*{box-sizing:border-box;margin:0;padding:0}.guide-heading-interactive-slot{margin:24px 0 34px}.matte4c-concept-lab{border:1px solid color-mix(in srgb, var(--purple) 22%, var(--line));background:radial-gradient(circle at 92% 8%, color-mix(in srgb, var(--pistachio) 34%, transparent), transparent 28%), linear-gradient(145deg, color-mix(in srgb, var(--card) 94%, var(--bronze-soft)), var(--card));box-shadow:0 18px 46px color-mix(in srgb, var(--navy) 8%, transparent);color:var(--ink);border-radius:20px;margin:0;padding:clamp(20px,3vw,30px)}.concept-lab-heading{justify-content:space-between;align-items:flex-start;gap:18px;display:flex}.concept-lab-kicker{color:var(--purple);font-family:var(--sans);letter-spacing:.11em;text-transform:uppercase;margin-bottom:7px;font-size:.72rem;font-weight:750;display:block}.matte4c-concept-lab h3{color:var(--navy);font-family:var(--serif);margin:0;font-size:clamp(1.42rem,2.5vw,2rem);line-height:1.12}.concept-lab-formula{border:1px solid color-mix(in srgb, var(--purple) 26%, var(--line));background:var(--card);color:var(--navy);font-family:var(--serif);white-space:nowrap;border-radius:999px;flex:none;padding:9px 13px;font-size:1rem;font-weight:700}.concept-lab-lead{max-width:820px;font-family:var(--serif);margin:13px 0 20px;font-size:1.04rem;line-height:1.62}.concept-lab-controls{gap:8px;margin:0 0 20px;display:grid}.concept-lab-controls button{border:1px solid var(--line);background:var(--card);min-width:0;min-height:48px;color:var(--ink-2);font:680 .84rem/1.2 var(--sans);cursor:pointer;border-radius:11px;justify-content:center;align-items:center;gap:8px;padding:9px 10px;display:flex}.concept-lab-controls button>span{background:var(--paper-2);width:21px;height:21px;color:var(--ink-2);border-radius:50%;flex:none;place-items:center;font-size:.7rem;display:grid}.concept-lab-controls button:hover{border-color:color-mix(in srgb, var(--purple) 48%, var(--line));color:var(--navy)}.concept-lab-controls button.active{border-color:var(--purple);background:color-mix(in srgb, var(--purple) 10%, var(--card));color:var(--navy);box-shadow:inset 0 0 0 1px color-mix(in srgb, var(--purple) 24%, transparent)}.concept-lab-controls button.active>span{background:var(--purple);color:#fff}.concept-lab-controls button:focus-visible,.math-range-label input[type=range]:focus-visible{outline:3px solid color-mix(in srgb, var(--purple) 58%, white);outline-offset:3px}.curve-vector-toggles label:has(input:focus-visible){outline:3px solid color-mix(in srgb, var(--purple) 58%, white);outline-offset:3px}.curve-kind-controls{grid-template-columns:repeat(2,minmax(0,1fr))}.smoothness-example-controls{grid-template-columns:repeat(3,minmax(0,1fr))}.curve-lab-grid,.surface-lab-grid{grid-template-columns:minmax(300px,1.35fr) minmax(235px,.65fr);align-items:stretch;gap:18px;display:grid}.curve-canvas,.surface-canvas,.curve-readout,.surface-controls,.smoothness-meter{border:1px solid var(--line);background:color-mix(in srgb, var(--paper) 72%, var(--card));border-radius:15px;min-width:0}.curve-canvas,.surface-canvas{overflow:hidden}.curve-canvas svg,.surface-canvas svg{width:100%;height:auto;display:block}.curve-grid-axis{fill:none;stroke:color-mix(in srgb, var(--ink-3) 35%, transparent);stroke-width:1.25px}.curve-trace{fill:none;stroke:var(--navy);stroke-linecap:round;stroke-linejoin:round;stroke-width:4px}.curve-vector,.surface-vector{stroke-linecap:round;stroke-width:4px}.curve-vector.velocity,.surface-vector.su{stroke:var(--purple)}.curve-vector.acceleration,.surface-vector.normal{stroke:var(--bronze)}.surface-vector.sv{stroke:var(--moss)}.curve-motion-lab marker path,.surface-tangent-lab marker[id$=-su] path{fill:var(--purple)}.curve-motion-lab marker[id$=-bronze] path,.surface-tangent-lab marker[id$=-normal] path{fill:var(--bronze)}.surface-tangent-lab marker[id$=-sv] path{fill:var(--moss)}.curve-moving-point,.surface-selected-point{fill:var(--logo-gold);stroke:var(--navy);stroke-width:3px}.math-range-label{border-top:1px solid var(--line);color:var(--ink-2);font:700 .82rem/1.35 var(--sans);gap:8px;padding:13px 16px 16px;display:grid}.math-range-label>span{justify-content:space-between;gap:12px;display:flex}.math-range-label small{color:var(--ink-3);font-weight:560}.math-range-label input[type=range]{width:100%;accent-color:var(--purple);cursor:grab}.math-range-label input[type=range]:active{cursor:grabbing}.curve-readout{grid-template-columns:repeat(2,minmax(0,1fr));align-content:start;gap:9px;padding:15px;display:grid}.curve-readout>div:not(.curve-vector-toggles){border:1px solid var(--line);background:var(--card);border-radius:11px;min-width:0;padding:11px}.curve-readout>div>span,.surface-vector-key b,.smoothness-status-label{color:var(--ink-3);font:720 .64rem/1.2 var(--sans);letter-spacing:.07em;text-transform:uppercase;margin-bottom:4px;display:block}.curve-readout>div>strong,.surface-vector-key strong{color:var(--navy);font:720 .98rem/1.25 var(--serif);font-variant-numeric:tabular-nums}.curve-vector-toggles{grid-column:1/-1;gap:8px;margin-top:3px;display:grid}.curve-vector-toggles label{border:1px solid var(--line);background:var(--card);min-height:42px;color:var(--ink-2);font:680 .79rem/1.25 var(--sans);cursor:pointer;border-radius:10px;align-items:center;gap:9px;padding:8px 10px;display:flex}.curve-vector-toggles input{accent-color:var(--purple)}.velocity-swatch,.acceleration-swatch,.su-swatch,.sv-swatch,.normal-swatch{background:var(--purple);border-radius:999px;flex:none;width:18px;height:3px;display:block}.acceleration-swatch,.normal-swatch{background:var(--bronze)}.sv-swatch{background:var(--moss)}.surface-grid-line{fill:none;stroke:color-mix(in srgb, var(--navy) 33%, var(--line));stroke-width:1.3px}.surface-tangent-plane{fill:color-mix(in srgb, var(--logo-gold) 31%, transparent);stroke:var(--bronze);stroke-dasharray:8 6;stroke-width:2.5px}.surface-controls{align-content:start;gap:10px;padding:14px;display:grid}.surface-controls .math-range-label{border:1px solid var(--line);background:var(--card);border-radius:10px;padding:10px 11px 12px}.surface-vector-key{gap:7px;display:grid}.surface-vector-key>div{border:1px solid var(--line);background:var(--card);border-radius:9px;grid-template-columns:auto 28px minmax(0,1fr);align-items:center;gap:8px;padding:8px 10px;display:grid}.surface-vector-key b{color:var(--ink-2);text-transform:none;margin:0}.surface-vector-key strong{overflow-wrap:anywhere;font-size:.85rem}.surface-controls .curve-vector-toggles{grid-template-columns:repeat(2,minmax(0,1fr))}.surface-status{border-left:4px solid var(--moss);background:color-mix(in srgb, var(--green-soft) 72%, var(--card));color:var(--ink-2);font:.82rem/1.45 var(--serif);border-radius:8px;margin:0;padding:10px 11px}.smoothness-meter{grid-template-columns:150px minmax(0,1fr);align-items:center;gap:22px;padding:20px;transition:border-color .18s,background .18s;display:grid}.smoothness-meter.smooth{border-color:color-mix(in srgb, var(--moss) 50%, var(--line));background:color-mix(in srgb, var(--green-soft) 58%, var(--card))}.smoothness-meter.collapsed{border-color:color-mix(in srgb, #b44f55 58%, var(--line));background:color-mix(in srgb, #f5dadd 45%, var(--card))}.smoothness-orbit{background:var(--card);width:126px;height:126px;box-shadow:inset 0 0 0 1px var(--line);border-radius:50%;place-items:center;display:grid;position:relative}.smoothness-orbit>span{background:conic-gradient(var(--moss) var(--smoothness-progress), color-mix(in srgb, var(--line) 70%, transparent) 0);border-radius:50%;position:absolute;inset:10px;-webkit-mask:radial-gradient(circle,#0000 54%,#000 56%);mask:radial-gradient(circle,#0000 54%,#000 56%)}.smoothness-meter.collapsed .smoothness-orbit>span{background:conic-gradient(#b44f55 var(--smoothness-progress), color-mix(in srgb, var(--line) 70%, transparent) 0)}.smoothness-orbit>b{z-index:1;color:var(--navy);font:750 1.45rem/1 var(--serif);font-variant-numeric:tabular-nums}.smoothness-meter>div:last-child>strong{color:var(--navy);font:680 clamp(1.16rem, 2vw, 1.5rem)/1.2 var(--serif);display:block}.smoothness-bar{background:color-mix(in srgb, var(--line) 72%, transparent);border-radius:999px;height:9px;margin:13px 0 10px;overflow:hidden}.smoothness-bar>i{border-radius:inherit;background:var(--moss);height:100%;transition:width .16s;display:block}.smoothness-meter.collapsed .smoothness-bar>i{background:#b44f55}.smoothness-meter p{color:var(--ink-2);font:.94rem/1.52 var(--serif);margin:0}.smoothness-range{border:1px solid var(--line);background:var(--card);border-radius:11px;margin-top:12px}@media (max-width:820px){.concept-lab-heading{flex-direction:column}.concept-lab-formula{align-self:flex-start}.curve-lab-grid,.surface-lab-grid{grid-template-columns:minmax(0,1fr)}.curve-readout{grid-template-columns:repeat(4,minmax(0,1fr))}.smoothness-meter{grid-template-columns:126px minmax(0,1fr)}}@media (max-width:620px){.matte4c-concept-lab{border-radius:15px;margin-inline:-4px;padding:18px 14px}.curve-readout{grid-template-columns:repeat(2,minmax(0,1fr))}.smoothness-example-controls,.smoothness-meter,.surface-controls .curve-vector-toggles{grid-template-columns:minmax(0,1fr)}.smoothness-orbit{justify-self:center}}@media (prefers-reduced-motion:reduce){.smoothness-meter,.smoothness-bar>i{transition:none}}:root{--paper:#f7f5f0;--paper-2:#efece5;--card:#fff;--ink:#171b40;--ink-2:#4e556e;--ink-3:#62687d;--navy:#142138;--navy-2:#1d3153;--line:#171b401a;--line-strong:#171b4033;--moss:#626b3d;--pistachio:#d9dd9a;--green-soft:#d9dd9a4d;--bronze:#806536;--bronze-soft:#886d3a17;--purple:#6b4a7a;--purple-soft:#f1eaf4;--logo-gold:#c9a15a;--paper-on-navy:#f4f1ea;--line-on-navy:#f4f1ea24;--serif:"STIX Two Text", Georgia, serif;--sans:"Schibsted Grotesk", -apple-system, sans-serif;--mono:"Spline Sans Mono", ui-monospace, monospace;--ease:cubic-bezier(.22, 1, .36, 1)}html{scroll-behavior:smooth}body{background:var(--paper);color:var(--ink);font-family:var(--sans);-webkit-font-smoothing:antialiased;font-size:16px;line-height:1.6;overflow-x:hidden}::selection{background:var(--navy);color:var(--paper-on-navy)}button{font-family:var(--sans)}.grid-bg{z-index:0;pointer-events:none;background-image:linear-gradient(#171b400b 1px,#0000 1px),linear-gradient(90deg,#171b400b 1px,#0000 1px);background-size:56px 56px;position:fixed;inset:0;-webkit-mask-image:radial-gradient(85% 60% at 50% 0,#000 0%,#0000 72%);mask-image:radial-gradient(85% 60% at 50% 0,#000 0%,#0000 72%)}.reveal{opacity:0;transition:opacity .9s var(--ease), transform .9s var(--ease);transform:translateY(26px)}.reveal.in{opacity:1;transform:none}.reveal.d1{transition-delay:.1s}.reveal.d2{transition-delay:.22s}.reveal.d3{transition-delay:.34s}@media (prefers-reduced-motion:reduce){*,:before,:after{transition-duration:.01ms!important;animation-duration:.01ms!important}.reveal{opacity:1;transform:none}}.site-nav{z-index:50;-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px);background:#f7f5f0d9;border-bottom:1px solid #0000;justify-content:space-between;align-items:center;padding:18px 48px;transition:border-color .4s;display:flex;position:fixed;top:0;left:0;right:0}.site-nav.scrolled{border-bottom-color:var(--line)}.brand{cursor:pointer;align-items:center;gap:12px;text-decoration:none;display:flex}.brand img,.brand svg{border-radius:9px;display:block}.brand-word{font-family:var(--sans);letter-spacing:.32em;color:var(--ink);text-transform:uppercase;font-size:15px;font-weight:700}.nav-links{align-items:center;gap:36px;display:flex}.nav-links a:not(.btn){color:var(--ink-2);cursor:pointer;font-size:14px;font-weight:500;text-decoration:none;transition:color .25s}.nav-links a:not(.btn):hover{color:var(--ink)}.nav-links .nav-personal-link{border:1px solid var(--line-strong);background:color-mix(in srgb, var(--card) 72%, transparent);min-height:38px;color:var(--ink);transition:border-color .2s, background .2s, transform .2s var(--ease);border-radius:999px;align-items:center;gap:7px;padding:7px 13px;font-weight:650;display:inline-flex}.nav-links .nav-personal-link:hover{border-color:var(--moss);background:var(--green-soft);transform:translateY(-1px)}.nav-personal-link:focus-visible{outline:2px solid var(--navy);outline-offset:3px}.btn{font-family:var(--sans);cursor:pointer;transition:transform .25s var(--ease), background .25s, border-color .25s, color .25s, box-shadow .25s;border:1px solid #0000;border-radius:100px;align-items:center;gap:10px;padding:13px 28px;font-size:14.5px;font-weight:600;text-decoration:none;display:inline-flex}.btn:focus-visible{outline:2px solid var(--navy);outline-offset:3px}.btn-navy{background:var(--navy);color:var(--paper-on-navy)}.btn-navy:hover{background:var(--navy-2);transform:translateY(-2px);box-shadow:0 14px 30px -14px #14213880}.btn-ghost{color:var(--ink);border-color:var(--line-strong);background:0 0}.btn-ghost:hover{border-color:var(--ink);transform:translateY(-2px)}.btn-paper{background:var(--paper-on-navy);color:var(--navy)}.btn-paper:hover{background:#fff;transform:translateY(-2px)}.hero{z-index:1;text-align:center;flex-direction:column;justify-content:center;align-items:center;min-height:100vh;padding:130px 24px 90px;display:flex;position:relative}.hero-curve{width:min(400px,78vw);margin-bottom:4px}.hero-curve .curve-path{stroke-dasharray:600;stroke-dashoffset:600px;animation:draw 1.6s var(--ease) .3s forwards}@keyframes draw{to{stroke-dashoffset:0}}.hero-curve .mean-line{opacity:0;animation:.6s 1.7s forwards fadein}.hero-curve .mean-dot{opacity:0;animation:dotDrop .55s var(--ease) 2s forwards;transform:translateY(-14px)}@keyframes fadein{to{opacity:1}}@keyframes dotDrop{to{opacity:1;transform:none}}.hero h1{font-family:var(--serif);letter-spacing:-.02em;max-width:16ch;color:var(--ink);font-size:clamp(2.9rem,6.8vw,5.1rem);font-weight:500;line-height:1.06}.hero h1 em{font-style:italic;font-weight:400}.hero .word{vertical-align:bottom;display:inline-block;overflow:hidden}.hero .word span{animation:rise .9s var(--ease) forwards;display:inline-block;transform:translateY(110%)}@keyframes rise{to{transform:none}}.hero-sub{color:var(--ink-2);opacity:0;max-width:54ch;margin-top:28px;font-size:clamp(1rem,1.6vw,1.15rem);animation:1s 2.5s forwards fadein}.hero-cta{opacity:0;gap:16px;margin-top:42px;animation:1s 2.75s forwards fadein;display:flex}.hero-stats{opacity:0;grid-template-columns:repeat(3,1fr);width:min(820px,92%);margin-top:84px;animation:1s 3s forwards fadein;display:grid}.stat{border-right:1px solid var(--line-strong);text-align:center;padding:6px 20px}.stat:last-child{border-right:none}.stat b{font-family:var(--serif);color:var(--ink);font-size:2.3rem;font-weight:500;line-height:1.15;display:block}.stat span{color:var(--ink-3);letter-spacing:.1em;text-transform:uppercase;font-size:12px;font-weight:500}.hero-updated{font-family:var(--mono);letter-spacing:.14em;color:var(--ink-3);opacity:0;margin-top:34px;font-size:11px;animation:1s 3.2s forwards fadein}.section{z-index:1;max-width:1240px;margin:0 auto;padding:130px 48px;position:relative}.eyebrow{font-family:var(--sans);letter-spacing:.24em;text-transform:uppercase;color:var(--ink-3);align-items:center;gap:14px;margin-bottom:24px;font-size:11.5px;font-weight:600;display:flex}.eyebrow:before{content:"";background:var(--moss);width:34px;height:1px}.section h2,.closing-inner h2,.problems-head h2{font-family:var(--serif);letter-spacing:-.015em;max-width:24ch;color:var(--ink);font-size:clamp(2rem,3.8vw,3.1rem);font-weight:500;line-height:1.12}.section h2 em,.closing-inner h2 em{font-style:italic;font-weight:400}.section-sub{color:var(--ink-2);max-width:58ch;margin-top:20px;font-size:1.05rem}.courses{grid-template-columns:repeat(auto-fit,minmax(255px,1fr));gap:26px;margin-top:70px;display:grid}.course{color:inherit;border:1px solid var(--line-strong);background:var(--card);cursor:pointer;transition:transform .35s var(--ease), box-shadow .35s var(--ease);box-shadow:6px 6px 0 -1px var(--paper), 6px 6px 0 0 var(--line-strong), 12px 12px 0 -2px var(--paper), 12px 12px 0 0 var(--line);border-radius:14px;padding:34px 30px 30px;text-decoration:none;display:block;position:relative}.course:hover,.course:focus-visible{box-shadow:9px 9px 0 -1px var(--paper), 9px 9px 0 0 var(--line-strong), 18px 18px 0 -2px var(--paper), 18px 18px 0 0 var(--line), 24px 30px 40px -24px #171b4047;transform:translate(-4px,-4px)}.course:focus-visible{outline:none}.course .curve-mini{opacity:.12;transition:opacity .35s;position:absolute;top:20px;right:16px}.course:hover .curve-mini{opacity:.32}.course .code{font-family:var(--mono);color:var(--ink-3);letter-spacing:.1em;font-size:11.5px}.course h3{font-family:var(--serif);color:var(--ink);margin:10px 0 6px;font-size:1.7rem;font-weight:600}.course p{color:var(--ink-2);max-width:30ch;font-size:14px;line-height:1.55}.course .meta{font-family:var(--mono);color:var(--ink-3);gap:18px;margin-top:26px;font-size:12px;display:flex}.course .meta b{color:var(--bronze);font-weight:500}.course .go{border:1px solid var(--line-strong);width:38px;height:38px;color:var(--ink-2);transition:all .3s var(--ease);border-radius:50%;place-items:center;display:grid;position:absolute;bottom:26px;right:26px}.course:hover .go{background:var(--navy);border-color:var(--navy);color:var(--paper-on-navy);transform:rotate(-45deg)}.course.course-wip{cursor:pointer;background:color-mix(in srgb, var(--card) 72%, var(--paper));border-color:var(--line);box-shadow:4px 4px 0 -1px var(--paper), 4px 4px 0 0 var(--line);opacity:1;overflow:hidden}.course.course-wip:hover,.course.course-wip:focus-visible{border-color:var(--line-strong);box-shadow:6px 6px 0 -1px var(--paper), 6px 6px 0 0 var(--line);transform:translate(-2px,-2px)}.course.course-wip .curve-mini,.course.course-wip:hover .curve-mini{opacity:.12}.course.course-wip .go{border-color:var(--line);color:var(--ink-3);background:0 0}.course-wip-badge{z-index:2;color:var(--ink-2);background:var(--paper);font-family:var(--mono);letter-spacing:.09em;text-transform:uppercase;border:1px solid;border-radius:999px;padding:5px 9px;font-size:10px;font-weight:600;position:absolute;top:18px;right:18px}.course-wip-access{color:var(--moss);flex-basis:100%;font-weight:600;display:block}.course.course-wip .meta{flex-wrap:wrap;gap:8px 18px;padding-right:44px}.stack-scroll{height:260vh;position:relative}.stack-sticky{grid-template-columns:1fr 1.1fr;align-items:center;gap:70px;max-width:1240px;height:100vh;margin:0 auto;padding:80px 48px 40px;display:grid;position:sticky;top:0}.layer-list{flex-direction:column;display:flex}.layer-item{text-align:left;border-bottom:1px solid var(--line);width:100%;font-family:var(--sans);color:var(--ink-2);align-items:baseline;gap:16px;padding:16px 4px;font-size:16px;font-weight:500;transition:color .3s;display:flex;position:relative}.layer-item:first-child{border-top:1px solid var(--line)}.layer-item .li-n{font-family:var(--mono);min-width:22px;color:var(--ink-2);font-size:11px;transition:color .3s}.layer-item .li-arrow{opacity:0;transition:all .3s var(--ease);color:var(--moss);margin-left:auto;transform:translate(-6px)}.layer-item.on{color:var(--ink);font-weight:600}.layer-item.on .li-n{color:var(--moss)}.layer-item.on .li-arrow{opacity:1;transform:none}.layer-item.done{color:var(--ink-2)}.layer-desc{color:var(--ink-2);max-width:46ch;min-height:104px;margin-top:28px;font-size:15.5px;line-height:1.7}.layer-desc.swap{animation:descIn .45s var(--ease)}@keyframes descIn{0%{transform:translateY(10px)}to{opacity:1;transform:none}}.stack-fig{justify-content:center;display:flex}.stack-fig svg{width:min(520px,100%);overflow:visible}.slab{filter:drop-shadow(0 22px 26px #171b4029)}.slab .slab-label{font-family:var(--sans);letter-spacing:.03em;fill:var(--ink);text-anchor:middle;font-size:15px;font-weight:600}.slab .slab-face{stroke:#0000;stroke-width:1.4px;transition:stroke .3s}.slab.on .slab-face{stroke:var(--moss)}#axiaLid .lid-label{font-family:var(--sans);letter-spacing:.28em;fill:var(--ink);text-anchor:middle;font-size:21px;font-weight:700}.how-band{background:var(--paper-2)}.how-band-inner{max-width:1240px;margin:0 auto;padding:130px 48px}.steps{grid-template-columns:repeat(3,1fr);gap:0;margin-top:74px;display:grid;position:relative}.steps:before{content:"";background-image:linear-gradient(90deg, var(--line-strong) 33%, transparent 0);background-size:9px 1px;height:1px;position:absolute;top:29px;left:12%;right:12%}.step{text-align:center;padding:0 30px}.step .n{z-index:1;background:var(--paper-2);border:1px solid var(--ink);width:58px;height:58px;color:var(--ink);font-family:var(--serif);border-radius:50%;place-items:center;margin:0 auto 26px;font-size:1.35rem;font-style:italic;display:grid;position:relative}.step h4{font-family:var(--serif);color:var(--ink);margin-bottom:10px;font-size:1.35rem;font-weight:600}.step p{color:var(--ink-2);font-size:14.5px}.closing-band{background:var(--navy);position:relative;overflow:hidden}.closing-inner{text-align:center;max-width:1240px;margin:0 auto;padding:150px 48px 140px;position:relative}.closing-inner h2{color:var(--paper-on-navy);margin:0 auto}.closing-inner h2 em{color:var(--pistachio)}.closing-inner .btn{margin-top:46px}.site-footer{background:var(--navy);border-top:1px solid var(--line-on-navy);color:#f4f1ea8c;justify-content:space-between;align-items:center;padding:34px 48px;font-size:13px;display:flex}.site-footer .brand-word{color:#f4f1ea8c;font-size:12px}.site-footer a{color:inherit;text-underline-offset:3px}.site-footer a:hover,.site-footer a:focus-visible{color:var(--paper-on-navy)}.footer-links{align-items:center;gap:20px;display:flex}.legal-page{background:var(--paper);min-height:100vh;color:var(--ink);padding:72px 48px 120px}.legal-hero,.legal-layout{width:min(1120px,100%);margin:0 auto}.legal-hero{border-bottom:1px solid var(--line-strong);padding:28px 0 64px}.legal-back{color:var(--ink-2);font-family:var(--mono);margin-bottom:64px;font-size:12px;text-decoration:none;display:inline-block}.legal-back:hover,.legal-back:focus-visible{color:var(--bronze)}.legal-hero h1{max-width:15ch;font-family:var(--serif);letter-spacing:-.035em;margin:14px 0 22px;font-size:clamp(2.7rem,6vw,5rem);font-weight:500;line-height:.98}.legal-hero>p{max-width:67ch;color:var(--ink-2);font-size:1.06rem;line-height:1.75}.legal-meta{color:var(--ink-3);font-family:var(--mono);letter-spacing:.06em;text-transform:uppercase;margin-top:24px;font-size:11px}.legal-layout{grid-template-columns:220px minmax(0,720px);justify-content:space-between;gap:80px;padding-top:64px;display:grid}.legal-toc{color:var(--ink-3);align-self:start;gap:11px;font-size:13px;display:grid;position:sticky;top:32px}.legal-toc span{color:var(--ink);font-family:var(--mono);letter-spacing:.1em;text-transform:uppercase;margin-bottom:7px;font-size:10px;font-weight:600}.legal-toc a{color:inherit;text-decoration:none}.legal-toc a:hover,.legal-toc a:focus-visible{color:var(--bronze)}.legal-copy section{padding:0 0 50px;scroll-margin-top:28px}.legal-copy h2{font-family:var(--serif);margin:0 0 20px;font-size:clamp(1.6rem,3vw,2.15rem);font-weight:600;line-height:1.2}.legal-copy h3{margin:28px 0 9px;font-size:1rem}.legal-copy p,.legal-copy li{color:var(--ink-2);font-size:15px;line-height:1.78}.legal-copy p+p{margin-top:14px}.legal-copy ul{gap:9px;margin:0 0 18px;padding-left:22px;display:grid}.legal-copy a{color:var(--ink);-webkit-text-decoration-color:var(--bronze);text-decoration-color:var(--bronze);text-underline-offset:3px}.legal-local-data-control .dashboard-panel-head{margin-bottom:16px}.legal-copy .legal-local-data-control h3{color:var(--navy);font-family:var(--serif);margin:4px 0 0;font-size:1.5rem;font-weight:550}@media (max-width:760px){.legal-page{padding:36px 22px 80px}.legal-back{margin-bottom:42px}.legal-layout{grid-template-columns:1fr;gap:44px;padding-top:44px}.legal-toc{grid-template-columns:repeat(2,minmax(0,1fr));position:static}.legal-toc span{grid-column:1/-1}}.course-shell{grid-template-columns:var(--col-units,280px) minmax(0, 1fr) var(--col-chat,minmax(400px, 34vw));background:var(--paper);min-height:100vh;transition:grid-template-columns .45s var(--ease);padding-top:73px;display:grid}.course-shell-wip{--paper:#f7f5f0;--paper-2:#efece5;--card:#fff}.course-shell-wip .problem,.course-shell-wip .ref-card,.course-shell-wip .guide-oppg,.course-shell-wip .formula-pane{filter:none}.course-shell-wip .problem{border-top:3px solid color-mix(in srgb, var(--moss) 78%, var(--pistachio));box-shadow:0 13px 32px -28px #171b4066}.course-shell-wip .problem-body .katex-display{background:linear-gradient(100deg, var(--green-soft), var(--card) 76%);border-left-width:4px}.course-shell-wip .solution{border-left:4px solid var(--purple);background:linear-gradient(135deg, var(--purple-soft), var(--paper) 68%)}.course-shell-wip .sol-label,.course-shell-wip .sol-pane strong{color:var(--purple)}.course-shell-wip .sol-pane .katex-display{border:1px solid color-mix(in srgb, var(--purple) 18%, var(--line));background:color-mix(in srgb, var(--card) 88%, var(--purple-soft));border-radius:10px;padding:10px 12px}.course-preview-label{border:1px solid color-mix(in srgb, var(--bronze) 48%, var(--line));color:var(--bronze);background:color-mix(in srgb, var(--bronze-soft) 82%, var(--card));font-family:var(--mono);letter-spacing:.09em;text-transform:uppercase;border-radius:999px;margin-top:14px;padding:5px 9px;font-size:10px;font-weight:600;display:inline-flex}.course-preview-warning{border:1px solid color-mix(in srgb, var(--moss) 28%, var(--line));border-left:5px solid var(--moss);background:linear-gradient(105deg, var(--green-soft), var(--card) 72%);color:var(--ink);border-radius:12px;grid-template-columns:minmax(0,1fr) auto;align-items:center;gap:18px 30px;margin-bottom:30px;padding:22px 24px;display:grid;position:relative;overflow:hidden}.course-preview-warning strong{font-family:var(--serif);margin-bottom:4px;font-size:1.08rem;display:block}.course-preview-warning p{max-width:72ch;color:var(--ink-2);font-size:13.5px;line-height:1.6}.course-preview-warning a{z-index:1;color:var(--ink);white-space:nowrap;text-underline-offset:3px;font-size:13px;font-weight:600;position:relative}.course-preview-warning-mark{color:var(--moss);opacity:.045;pointer-events:none;font-size:150px;font-weight:200;line-height:1;position:absolute;bottom:-72px;right:12%}.contact-page{background:var(--paper);min-height:100vh;padding:72px 48px 120px}.contact-wrap{width:min(820px,100%);margin:0 auto}.contact-form{border:1px solid var(--line-strong);background:var(--card);box-shadow:8px 8px 0 -1px var(--paper), 8px 8px 0 0 var(--line);border-radius:16px;gap:22px;margin-top:46px;padding:30px;display:grid}.contact-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:18px;display:grid}.contact-field{gap:8px;display:grid}.contact-field label{color:var(--ink);font-size:13px;font-weight:600}.contact-field input,.contact-field select,.contact-field textarea{border:1px solid var(--line-strong);background:var(--paper);width:100%;color:var(--ink);font:inherit;border-radius:9px;padding:12px 13px}.contact-field textarea{resize:vertical;min-height:190px}.contact-field input:focus,.contact-field select:focus,.contact-field textarea:focus{outline:2px solid var(--navy);outline-offset:2px}.contact-help{color:var(--ink-3);font-size:12px;line-height:1.6}.contact-actions{flex-wrap:wrap;align-items:center;gap:18px;display:flex}.contact-status{color:var(--moss);font-size:13px}@media (max-width:700px){.site-footer,.footer-links,.contact-actions{align-items:flex-start}.site-footer{flex-direction:column;gap:16px;padding:30px 22px}.footer-links{flex-wrap:wrap}.course-preview-warning{grid-template-columns:1fr}.contact-page{padding:36px 22px 80px}.contact-grid{grid-template-columns:1fr}.contact-form{padding:22px}}.dashboard-nav .nav-personal-link[aria-current=page]{border-color:var(--moss);background:var(--green-soft);color:var(--ink)}.dashboard-page{width:min(1420px,100%);min-height:100vh;margin:0 auto;padding:132px 48px 90px}.dashboard-hero{grid-template-columns:minmax(0,1.35fr) minmax(320px,.65fr);align-items:end;gap:42px;margin-bottom:38px;display:grid}.dashboard-hero h1{max-width:820px;color:var(--navy);font-family:var(--serif);letter-spacing:-.035em;margin-top:10px;font-size:clamp(2.5rem,5.2vw,5.1rem);font-weight:500;line-height:.98}.dashboard-hero>div>p{max-width:690px;color:var(--ink-2);margin-top:20px;font-size:16px;line-height:1.7}.local-data-note{border:1px solid color-mix(in srgb, var(--moss) 36%, transparent);background:var(--green-soft);color:var(--moss);border-radius:14px;grid-template-columns:auto minmax(0,1fr);align-items:start;gap:12px;padding:17px 18px;display:grid}.local-data-note.error{border-color:color-mix(in srgb, var(--purple) 35%, transparent);background:var(--purple-soft);color:var(--purple)}.local-data-note strong,.local-data-note span{display:block}.local-data-note strong{color:var(--ink);margin-bottom:3px;font-size:12.5px}.local-data-note span{color:var(--ink-2);font-size:11.5px;line-height:1.5}.dashboard-course-filter,.dashboard-item-filters{scrollbar-width:thin;gap:8px;display:flex;overflow-x:auto}.dashboard-course-filter{z-index:20;background:color-mix(in srgb, var(--paper) 94%, transparent);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);margin:0 0 26px;padding:12px 0;position:sticky;top:73px}.dashboard-course-filter button,.dashboard-item-filters button{border:1px solid var(--line-strong);background:var(--card);min-height:38px;color:var(--ink-2);cursor:pointer;border-radius:999px;flex:none;padding:8px 14px;font-size:12px;font-weight:650;transition:border-color .2s,background .2s,color .2s}.dashboard-course-filter button:hover,.dashboard-item-filters button:hover{border-color:var(--moss);color:var(--ink)}.dashboard-course-filter button.active,.dashboard-item-filters button.active{border-color:var(--navy);background:var(--navy);color:var(--paper-on-navy)}.dashboard-course-filter button:focus-visible,.dashboard-item-filters button:focus-visible,.dashboard-data-footer button:focus-visible{outline:2px solid var(--navy);outline-offset:3px}.dashboard-loading{grid-template-columns:repeat(3,minmax(0,1fr));gap:16px;display:grid}.dashboard-loading span{border:1px solid var(--line);background:linear-gradient(100deg, var(--paper-2) 20%, var(--card) 42%, var(--paper-2) 64%);background-size:300% 100%;border-radius:16px;height:150px;animation:1.4s ease-in-out infinite dashboard-shimmer;display:block}@keyframes dashboard-shimmer{to{background-position:-180% 0}}.dashboard-empty{border:1px solid var(--line-strong);background:var(--card);min-height:390px;box-shadow:12px 12px 0 -1px var(--paper), 12px 12px 0 0 var(--line);border-radius:22px;grid-template-columns:.45fr minmax(0,1fr);align-items:center;gap:44px;padding:clamp(30px,6vw,76px);display:grid;position:relative;overflow:hidden}.dashboard-empty-mark{color:var(--pistachio);font-family:var(--serif);text-align:center;font-size:clamp(8rem,20vw,17rem);font-weight:400;line-height:.6}.dashboard-empty h2,.dashboard-panel h2,.dashboard-worklist h2{color:var(--navy);font-family:var(--serif);letter-spacing:-.02em;font-weight:550}.dashboard-empty h2{margin:8px 0 12px;font-size:clamp(2rem,4vw,3.4rem);line-height:1.05}.dashboard-empty p{max-width:570px;color:var(--ink-2);margin-bottom:24px}.dashboard-kpis{grid-template-columns:repeat(4,minmax(0,1fr));gap:12px;margin-bottom:18px;display:grid}.dashboard-kpis article{border:1px solid var(--line);background:var(--card);border-radius:15px;min-height:160px;padding:20px}.dashboard-kpis article>span{color:var(--ink-3);font-family:var(--mono);letter-spacing:.12em;text-transform:uppercase;font-size:9.5px;font-weight:600}.dashboard-kpis strong{color:var(--navy);font-family:var(--serif);margin:8px 0 4px;font-size:3.2rem;font-weight:500;line-height:1;display:block}.dashboard-kpis p{color:var(--ink-3);font-size:11.5px;line-height:1.45}.dashboard-main-grid{grid-template-columns:minmax(0,1.35fr) minmax(320px,.65fr);gap:18px;margin-bottom:18px;display:grid}.dashboard-panel{border:1px solid var(--line);background:var(--card);border-radius:17px;padding:24px}.dashboard-panel-head,.dashboard-worklist-head{justify-content:space-between;align-items:flex-start;gap:18px;margin-bottom:20px;display:flex}.dashboard-panel-head h2,.dashboard-worklist-head h2{margin-top:4px;font-size:clamp(1.45rem,2.5vw,2rem);line-height:1.12}.dashboard-panel-head>span{background:var(--paper);color:var(--ink-3);font-family:var(--mono);border-radius:999px;flex:none;padding:5px 9px;font-size:9.5px}.priority-list{gap:8px;display:grid}.priority-row{border:1px solid var(--line);color:var(--ink);transition:border-color .2s, background .2s, transform .2s var(--ease);border-radius:12px;grid-template-columns:auto minmax(0,1fr) auto auto;align-items:center;gap:14px;padding:13px 14px;text-decoration:none;display:grid}.priority-row:hover{border-color:var(--moss);background:var(--green-soft);transform:translate(2px)}.priority-number{color:var(--bronze);font-family:var(--mono);font-size:10px}.priority-row>div:nth-child(2) strong,.priority-row>div:nth-child(2) span{display:block}.priority-row>div:nth-child(2) strong{font-size:13.5px}.priority-row>div:nth-child(2) span{color:var(--ink-3);margin-top:2px;font-size:10.5px}.priority-signals{flex-wrap:wrap;justify-content:flex-end;gap:5px;display:flex}.priority-signals span{background:var(--bronze-soft);color:var(--bronze);border-radius:999px;padding:4px 7px;font-size:9.5px;font-weight:650}.priority-arrow{color:var(--moss)}.dashboard-panel-empty,.dashboard-filter-empty{border:1px dashed var(--line-strong);color:var(--ink-3);text-align:center;border-radius:12px;padding:20px;font-size:13px}.difficulty-distribution-bar{background:var(--paper-2);border-radius:999px;height:18px;margin:34px 0 18px;display:flex;overflow:hidden}.difficulty-distribution-bar span{min-width:4px}.distribution-1{background:var(--moss)}.distribution-2{background:var(--bronze)}.distribution-3{background:var(--purple)}.distribution-legend{gap:8px;display:grid}.distribution-legend>div{color:var(--ink-2);grid-template-columns:auto 1fr auto;align-items:center;gap:8px;font-size:12px;display:grid}.legend-dot{border-radius:50%;width:8px;height:8px}.legend-dot-1{background:var(--moss)}.legend-dot-2{background:var(--bronze)}.legend-dot-3{background:var(--purple)}.distribution-legend strong{color:var(--ink);font-family:var(--mono);font-size:11px}.dashboard-distribution>p{border-top:1px solid var(--line);color:var(--ink-3);margin-top:20px;padding-top:16px;font-size:10.5px;line-height:1.55}.dashboard-units{margin-bottom:42px}.unit-progress-list{grid-template-columns:repeat(2,minmax(0,1fr));gap:9px;display:grid}.unit-progress-row{border:1px solid var(--line);min-height:74px;color:var(--ink);border-radius:12px;grid-template-columns:minmax(0,1fr) auto auto;align-items:center;gap:16px;padding:12px 14px;text-decoration:none;transition:border-color .2s,background .2s;display:grid}.unit-progress-row:hover{border-color:var(--moss);background:var(--green-soft)}.unit-progress-title span,.unit-progress-title strong{display:block}.unit-progress-title span{color:var(--ink-3);font-family:var(--mono);letter-spacing:.05em;text-transform:uppercase;margin-bottom:2px;font-size:8.5px}.unit-progress-title strong{font-size:12.5px}.unit-mini-bar{grid-template-columns:repeat(3,27px);gap:3px;display:grid}.unit-mini-bar span{color:#fff;height:24px;font-family:var(--mono);border-radius:6px;place-items:center;font-size:9px;display:grid}.unit-mini-1{background:var(--moss)}.unit-mini-2{background:var(--bronze)}.unit-mini-3{background:var(--purple)}.unit-progress-status{background:var(--green-soft);color:var(--moss);white-space:nowrap;border-radius:999px;padding:5px 8px;font-size:9.5px;font-weight:700}.unit-progress-status.needs-work{background:var(--purple-soft);color:var(--purple)}.dashboard-worklist{margin-bottom:42px}.dashboard-items-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;display:grid}.dashboard-item{border:1px solid var(--line);background:var(--card);min-height:250px;transition:border-color .2s, box-shadow .2s, transform .2s var(--ease);border-radius:15px;flex-direction:column;padding:19px;display:flex}.dashboard-item:hover{border-color:var(--line-strong);transform:translateY(-2px);box-shadow:0 18px 34px -28px #171b4066}.dashboard-item-top{flex-wrap:wrap;align-items:center;gap:6px;margin-bottom:16px;display:flex}.dashboard-kind,.dashboard-difficulty,.dashboard-saved{letter-spacing:.04em;text-transform:uppercase;border-radius:999px;padding:4px 7px;font-size:9px;font-weight:700}.dashboard-kind{background:var(--paper-2);color:var(--ink-2)}.dashboard-difficulty-1{background:var(--green-soft);color:var(--moss)}.dashboard-difficulty-2{background:var(--bronze-soft);color:var(--bronze)}.dashboard-difficulty-3{background:var(--purple-soft);color:var(--purple)}.dashboard-saved{border:1px solid color-mix(in srgb, var(--moss) 32%, transparent);color:var(--moss)}.dashboard-updated{color:var(--ink-3);font-family:var(--mono);margin-left:auto;font-size:8.5px}.dashboard-item h3{color:var(--navy);font-family:var(--serif);font-size:1.25rem;font-weight:600;line-height:1.2}.dashboard-item-context{color:var(--ink-3);margin-top:7px;font-size:10.5px;line-height:1.45}.dashboard-note{border-left:2px solid var(--moss);color:var(--ink-2);font-family:var(--serif);white-space:pre-wrap;margin:18px 0;padding-left:12px;font-size:13px;font-style:italic;line-height:1.55}.dashboard-item>a{width:fit-content;color:var(--moss);align-items:center;gap:8px;margin-top:auto;padding-top:18px;font-size:12px;font-weight:700;text-decoration:none;display:inline-flex}.dashboard-item>a:hover{color:var(--ink)}.dashboard-data-footer{border-top:1px solid var(--line);justify-content:space-between;align-items:center;gap:24px;padding-top:24px;display:flex}.dashboard-data-footer strong,.dashboard-data-footer span{display:block}.dashboard-data-footer strong{color:var(--ink);font-size:12px}.dashboard-data-footer span{color:var(--ink-3);margin-top:2px;font-size:10.5px}.dashboard-data-footer button{border:1px solid var(--line-strong);color:var(--ink-3);cursor:pointer;background:0 0;border-radius:999px;flex:none;padding:8px 13px;font-size:11px;font-weight:650}.dashboard-data-footer button:hover{border-color:var(--purple);color:var(--purple)}.dashboard-account-deletion{margin:-20px 0 42px}.dashboard-account-delete-confirm{border-top:1px solid var(--line);gap:13px;margin-top:20px;padding-top:20px;display:grid}.dashboard-account-delete-confirm p{max-width:66ch;color:var(--ink-3);margin-top:5px;font-size:11.5px;line-height:1.55}.dashboard-account-delete-confirm>label{color:var(--ink-2);font-size:11px;font-weight:650}.dashboard-account-delete-confirm>input{border:1px solid var(--line-strong);background:var(--paper);width:min(100%,280px);min-height:42px;color:var(--ink);font:inherit;border-radius:10px;padding:9px 11px;font-size:13px}.dashboard-account-delete-confirm>input:focus-visible{outline:2px solid var(--navy);outline-offset:3px}.dashboard-account-delete-confirm button:disabled{cursor:not-allowed;opacity:.5}.dashboard-import-prompt{border:1px solid color-mix(in srgb, var(--moss) 46%, var(--line));background:var(--green-soft);border-radius:17px;grid-template-columns:minmax(0,1fr) auto;align-items:end;gap:28px;margin:0 0 28px;padding:24px;display:grid}.dashboard-import-prompt h2{max-width:24ch;color:var(--navy);font-family:var(--serif);margin:6px 0 9px;font-size:clamp(1.45rem,2.8vw,2.1rem);font-weight:550;line-height:1.12}.dashboard-import-prompt p{max-width:72ch;color:var(--ink-2);font-size:12px;line-height:1.6}.dashboard-import-ownership{max-width:68ch;color:var(--ink-2);align-items:flex-start;gap:9px;margin-top:13px;font-size:12px;font-weight:650;line-height:1.45;display:flex}.dashboard-import-ownership input{width:16px;height:16px;accent-color:var(--navy);flex:none;margin-top:1px}.dashboard-import-actions{flex-wrap:wrap;justify-content:flex-end;gap:8px;max-width:310px;display:flex}.dashboard-import-actions button{border:1px solid var(--line-strong);background:var(--card);min-height:40px;color:var(--ink-2);cursor:pointer;border-radius:999px;padding:8px 13px;font-size:11px;font-weight:700}.dashboard-import-actions .dashboard-import-primary{border-color:var(--navy);background:var(--navy);color:var(--paper-on-navy)}.dashboard-import-actions button:hover{border-color:var(--moss);color:var(--moss)}.dashboard-import-actions .dashboard-import-primary:hover{border-color:var(--navy-2);background:var(--navy-2);color:var(--paper-on-navy)}.dashboard-import-actions button:focus-visible{outline:2px solid var(--navy);outline-offset:3px}.dashboard-import-actions button:disabled{cursor:not-allowed;opacity:.48}.dashboard-import-error,.dashboard-import-success{border-radius:10px;margin-top:12px;padding:10px 12px;font-size:11px}.dashboard-import-error{background:var(--purple-soft);color:var(--purple)}.dashboard-import-success{border:1px solid color-mix(in srgb, var(--moss) 34%, transparent);background:var(--green-soft);color:var(--moss);margin:-12px 0 28px}.sr-only{clip:rect(0 0 0 0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}.dashboard-home-hero,.dashboard-course-hero,.dashboard-section-heading{justify-content:space-between;align-items:flex-end;gap:28px;display:flex}.dashboard-home-hero{margin-bottom:40px}.dashboard-home-hero h1,.dashboard-course-hero h1{color:var(--navy);font-family:var(--serif);letter-spacing:-.045em;margin-top:8px;font-size:clamp(3.2rem,7vw,6.4rem);font-weight:500;line-height:.92}.dashboard-manage-courses,.dashboard-open-course,.dashboard-add-course-banner button{border:1px solid var(--line-strong);background:var(--card);min-height:42px;color:var(--ink-2);cursor:pointer;border-radius:999px;justify-content:center;align-items:center;gap:9px;padding:9px 15px;font-size:12px;font-weight:700;text-decoration:none;transition:border-color .2s,background .2s,color .2s;display:inline-flex}.dashboard-manage-courses:hover,.dashboard-open-course:hover,.dashboard-add-course-banner button:hover{border-color:var(--moss);background:var(--green-soft);color:var(--ink)}.dashboard-manage-courses:focus-visible,.dashboard-open-course:focus-visible,.dashboard-add-course-banner button:focus-visible{outline:2px solid var(--navy);outline-offset:3px}.dashboard-course-library{margin-bottom:52px}.dashboard-section-heading{margin-bottom:22px}.dashboard-section-heading h2{color:var(--navy);font-family:var(--serif);letter-spacing:-.025em;margin-top:5px;font-size:clamp(1.8rem,3vw,2.8rem);font-weight:550}.dashboard-section-heading>span{background:var(--paper-2);color:var(--ink-3);font-family:var(--mono);border-radius:999px;padding:6px 10px;font-size:9.5px}.dashboard-course-cards{grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;display:grid}.dashboard-course-card{border:1px solid var(--line-strong);background:var(--card);min-height:390px;color:var(--ink);box-shadow:10px 10px 0 -1px var(--paper), 10px 10px 0 0 var(--line);transition:border-color .2s, transform .25s var(--ease), box-shadow .25s;border-radius:20px;flex-direction:column;padding:clamp(24px,4vw,40px);text-decoration:none;display:flex;position:relative;overflow:hidden}.dashboard-course-card:hover{border-color:var(--moss);box-shadow:13px 13px 0 -1px var(--paper), 13px 13px 0 0 var(--moss);transform:translate(-2px,-2px)}.dashboard-course-card-top{color:var(--moss);font-family:var(--mono);letter-spacing:.08em;text-transform:uppercase;justify-content:space-between;font-size:10px;font-weight:700;display:flex}.dashboard-course-card-top span:last-child{font-family:var(--sans);font-size:18px}.dashboard-course-card h3{max-width:620px;color:var(--navy);font-family:var(--serif);letter-spacing:-.035em;margin-top:34px;font-size:clamp(2rem,4vw,3.5rem);font-weight:520;line-height:1}.dashboard-course-card>p{max-width:620px;color:var(--ink-2);margin-top:16px;font-size:12px;line-height:1.65}.dashboard-course-card-stats{grid-template-columns:repeat(3,minmax(0,1fr));gap:10px;margin-top:auto;padding-top:34px;display:grid}.dashboard-course-card-stats div{border-top:1px solid var(--line);padding-top:12px}.dashboard-course-card-stats strong,.dashboard-course-card-stats span{display:block}.dashboard-course-card-stats strong{color:var(--navy);font-family:var(--serif);font-size:1.8rem;font-weight:550}.dashboard-course-card-stats span{color:var(--ink-3);margin-top:2px;font-size:9.5px;line-height:1.35}.dashboard-course-card-progress{background:var(--paper-2);border-radius:999px;height:5px;margin-top:18px;overflow:hidden}.dashboard-course-card-progress span{border-radius:inherit;background:var(--moss);height:100%;display:block}.dashboard-course-empty button{width:fit-content}.subject-picker-dialog{border:1px solid var(--line-strong);background:var(--paper);width:min(860px,100% - 32px);max-height:min(820px,100dvh - 32px);color:var(--ink);border-radius:22px;margin:auto;padding:0;overflow:auto;box-shadow:0 30px 90px #171b4047}.subject-picker-dialog::backdrop{-webkit-backdrop-filter:blur(8px);backdrop-filter:blur(8px);background:#10143194}.subject-picker-topline{border-bottom:1px solid var(--line);color:var(--ink-3);font-family:var(--mono);letter-spacing:.11em;text-transform:uppercase;justify-content:space-between;align-items:center;padding:16px 22px;font-size:9px;font-weight:700;display:flex}.subject-picker-topline button{border:1px solid var(--line);background:var(--card);width:34px;height:34px;color:var(--ink-2);cursor:pointer;border-radius:50%;place-items:center;font-size:20px;line-height:1;display:grid}.subject-picker-copy{padding:34px 34px 24px}.subject-picker-copy h2{max-width:650px;color:var(--navy);font-family:var(--serif);letter-spacing:-.035em;font-size:clamp(2.2rem,5vw,4.2rem);font-weight:520;line-height:1}.subject-picker-copy p{max-width:650px;color:var(--ink-2);margin-top:16px;font-size:14px;line-height:1.65}.subject-picker-grid{border:0;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;padding:0 34px;display:grid}.subject-picker-grid legend{width:100%;color:var(--ink-3);font-family:var(--mono);letter-spacing:.09em;text-transform:uppercase;margin-bottom:10px;font-size:9px}.subject-picker-grid label{border:1px solid var(--line);background:var(--card);cursor:pointer;border-radius:13px;grid-template-columns:auto minmax(0,1fr);align-items:center;gap:12px;min-height:72px;padding:13px;transition:border-color .2s,background .2s;display:grid}.subject-picker-grid label.selected{border-color:var(--moss);background:var(--green-soft)}.subject-picker-grid input{opacity:0;width:1px;height:1px;position:absolute}.subject-picker-check{border:1px solid var(--line-strong);background:var(--paper);width:25px;height:25px;color:var(--moss);border-radius:7px;place-items:center;font-size:14px;font-weight:800;display:grid}.subject-picker-grid label:has(input:focus-visible){outline:2px solid var(--navy);outline-offset:3px}.subject-picker-grid strong,.subject-picker-grid small{display:block}.subject-picker-grid strong{color:var(--ink);font-size:13px}.subject-picker-grid small{color:var(--ink-3);font-family:var(--mono);margin-top:2px;font-size:9px}.subject-picker-actions{border-top:1px solid var(--line);justify-content:flex-end;align-items:center;gap:12px;margin-top:28px;padding:20px 34px 28px;display:flex}.subject-picker-actions .btn:disabled{opacity:.42;cursor:not-allowed}.subject-picker-later{color:var(--ink-3);cursor:pointer;background:0 0;border:0;padding:10px 12px;font-size:12px;font-weight:650}.dashboard-course-nav{z-index:20;background:color-mix(in srgb, var(--paper) 94%, transparent);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);scrollbar-width:thin;gap:7px;margin:-26px 0 38px;padding:12px 0;display:flex;position:sticky;top:73px;overflow-x:auto}.dashboard-course-nav a,.dashboard-course-nav button{border:1px solid var(--line);background:var(--card);min-height:36px;color:var(--ink-2);cursor:pointer;border-radius:999px;flex:none;padding:8px 13px;font-size:11px;font-weight:650;text-decoration:none}.dashboard-course-nav a[aria-current=page]{border-color:var(--navy);background:var(--navy);color:var(--paper-on-navy)}.dashboard-course-nav button{margin-left:auto}.dashboard-course-hero{margin-bottom:34px}.dashboard-open-course{flex:none}.dashboard-add-course-banner{border:1px solid color-mix(in srgb, var(--moss) 40%, transparent);background:var(--green-soft);border-radius:14px;justify-content:space-between;align-items:center;gap:20px;margin-bottom:22px;padding:15px 17px;display:flex}.dashboard-add-course-banner strong,.dashboard-add-course-banner span{display:block}.dashboard-add-course-banner strong{color:var(--ink);font-size:12.5px}.dashboard-add-course-banner span{color:var(--ink-2);margin-top:2px;font-size:10.5px}.dashboard-kpis-six{grid-template-columns:repeat(3,minmax(0,1fr))}.dashboard-course-page .unit-progress-row{grid-template-columns:minmax(230px,1.15fr) minmax(100px,.55fr) minmax(180px,.8fr) auto}.unit-mastery-meter{background:var(--paper-2);border-radius:999px;height:7px;overflow:hidden}.unit-mastery-meter span{border-radius:inherit;background:var(--moss);height:100%;display:block}.unit-row-signals{flex-wrap:wrap;gap:5px;display:flex}.unit-row-signals span,.unit-no-checklist{background:var(--paper-2);color:var(--ink-3);white-space:nowrap;border-radius:999px;padding:4px 7px;font-size:9px}.dashboard-storage-error{border:1px solid color-mix(in srgb, var(--purple) 34%, transparent);background:var(--purple-soft);color:var(--purple);border-radius:12px;margin-top:28px;padding:12px 14px;font-size:11px}.dashboard-storage-error>p{margin:0}.dashboard-storage-error>a{color:inherit;text-underline-offset:3px;margin-top:8px;font-weight:700;display:inline-block}.dashboard-checklist{border:1px solid var(--line-strong);background:var(--card);border-radius:20px;margin:0 0 44px;padding:clamp(20px,3.5vw,34px)}.dashboard-checklist-head{grid-template-columns:minmax(0,1fr) auto;align-items:end;gap:28px;display:grid}.dashboard-checklist h2{color:var(--navy);font-family:var(--serif);letter-spacing:-.025em;margin-top:5px;font-size:clamp(1.8rem,3vw,2.8rem);font-weight:550;line-height:1.08}.dashboard-checklist-head>div:first-child>p,.dashboard-checklist-coming>p{max-width:660px;color:var(--ink-2);margin-top:11px;font-size:12px;line-height:1.6}.checklist-total-progress{border-left:1px solid var(--line);min-width:150px;padding-left:24px}.checklist-total-progress strong,.checklist-total-progress span{display:block}.checklist-total-progress strong{color:var(--moss);font-family:var(--serif);font-size:3rem;font-weight:520;line-height:.9}.checklist-total-progress span{color:var(--ink-3);margin-top:7px;font-size:9.5px}.checklist-toolbar{border-top:1px solid var(--line);grid-template-columns:minmax(220px,.45fr) minmax(0,1fr);align-items:center;gap:12px;margin:28px 0 18px;padding-top:20px;display:grid}.checklist-search{border:1px solid var(--line-strong);background:var(--paper);height:42px;color:var(--ink-3);border-radius:999px;align-items:center;gap:9px;padding:0 14px;display:flex}.checklist-search:focus-within{outline:2px solid var(--navy);outline-offset:2px}.checklist-search input{min-width:0;color:var(--ink);font:inherit;background:0 0;border:0;outline:0;flex:1;font-size:11px}.checklist-filters{scrollbar-width:thin;justify-content:flex-end;gap:6px;display:flex;overflow-x:auto}.checklist-filters button{border:1px solid var(--line);background:var(--paper);min-height:36px;color:var(--ink-2);cursor:pointer;border-radius:999px;flex:none;align-items:center;gap:6px;padding:7px 10px;font-size:9.5px;font-weight:650;display:inline-flex}.checklist-filters button span{background:var(--paper-2);min-width:19px;height:19px;color:var(--ink-3);font-family:var(--mono);border-radius:999px;place-items:center;font-size:8px;display:grid}.checklist-filters button.active{border-color:var(--navy);background:var(--navy);color:var(--paper-on-navy)}.checklist-filters button.active span{color:inherit;background:#ffffff26}.checklist-units{gap:9px;display:grid}.checklist-unit{border:1px solid var(--line);background:var(--paper);border-radius:13px;overflow:hidden}.checklist-unit-toggle{width:100%;min-height:74px;color:var(--ink);text-align:left;cursor:pointer;background:0 0;border:0;grid-template-columns:auto minmax(210px,1fr) minmax(100px,.45fr) auto auto;align-items:center;gap:14px;padding:12px 15px;display:grid}.checklist-unit-toggle:hover{background:var(--green-soft)}.checklist-unit-toggle:focus-visible{outline:2px solid var(--navy);outline-offset:-3px}.checklist-unit-number{color:var(--bronze);font-family:var(--mono);font-size:10px}.checklist-unit-title strong,.checklist-unit-title small{display:block}.checklist-unit-title strong{font-size:13px}.checklist-unit-title small{color:var(--ink-3);margin-top:2px;font-size:9.5px}.checklist-unit-meter{background:var(--paper-2);border-radius:999px;height:6px;overflow:hidden}.checklist-unit-meter span{border-radius:inherit;background:var(--moss);height:100%;display:block}.checklist-unit-percent{color:var(--moss);white-space:nowrap;font-size:9.5px;font-weight:700}.checklist-unit-chevron{color:var(--ink-3);font-size:19px;transition:transform .2s;transform:rotate(0)}.checklist-unit-toggle[aria-expanded=true] .checklist-unit-chevron{transform:rotate(180deg)}.checklist-skill-list{border-top:1px solid var(--line);display:grid}.checklist-skill-row{border-bottom:1px solid var(--line);background:var(--card);content-visibility:auto;contain-intrinsic-size:140px;border-left:3px solid #0000;grid-template-columns:minmax(0,1fr) minmax(180px,.28fr);align-items:start;gap:24px;padding:18px 19px 18px 16px;display:grid}.checklist-skill-row:last-child{border-bottom:0}.checklist-skill-row.status-learning{border-left-color:var(--purple)}.checklist-skill-row.status-uncertain{border-left-color:var(--bronze)}.checklist-skill-row.status-can,.checklist-skill-row.status-solid{border-left-color:var(--moss)}.checklist-skill-copy>span{color:var(--ink-3);font-family:var(--mono);letter-spacing:.09em;text-transform:uppercase;font-size:8px;font-weight:700}.checklist-skill-copy h3{color:var(--navy);font-family:var(--serif);margin-top:5px;font-size:1.15rem;font-weight:600;line-height:1.2}.checklist-skill-copy>p{max-width:790px;color:var(--ink-2);margin-top:6px;font-size:11px;line-height:1.55}.checklist-study-links{flex-wrap:wrap;gap:6px;margin-top:12px;display:flex}.checklist-study-links a{border-bottom:1px solid color-mix(in srgb, var(--moss) 38%, transparent);color:var(--moss);font-size:9.5px;font-weight:700;text-decoration:none}.checklist-study-links a:hover{color:var(--ink)}.checklist-mastery-select span{color:var(--ink-3);margin-bottom:6px;font-size:8.5px;font-weight:650;display:block}.checklist-mastery-select select{border:1px solid var(--line-strong);background:var(--paper);width:100%;min-height:39px;color:var(--ink-2);font:inherit;border-radius:10px;padding:8px 30px 8px 10px;font-size:10.5px;font-weight:700}.checklist-mastery-select select.status-learning{border-color:var(--purple);color:var(--purple)}.checklist-mastery-select select.status-uncertain{border-color:var(--bronze);color:var(--bronze)}.checklist-mastery-select select.status-can,.checklist-mastery-select select.status-solid{border-color:var(--moss);color:var(--moss)}.checklist-mastery-select select:focus-visible{outline:2px solid var(--navy);outline-offset:2px}@media (max-width:1080px){.dashboard-hero,.dashboard-main-grid{grid-template-columns:1fr}.dashboard-hero{align-items:start}.local-data-note{max-width:680px}.dashboard-items-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.unit-progress-list{grid-template-columns:1fr}.dashboard-course-page .unit-progress-row{grid-template-columns:minmax(210px,1fr) minmax(100px,.5fr) auto}.dashboard-course-page .unit-row-signals{grid-column:1/3}.checklist-toolbar{grid-template-columns:1fr}.checklist-filters{justify-content:flex-start}}@media (max-width:760px){.dashboard-page{padding:112px 22px 70px}.dashboard-hero{gap:24px;margin-bottom:20px}.dashboard-hero h1{font-size:clamp(2.4rem,13vw,4rem)}.dashboard-course-filter{margin-inline:-22px;padding-inline:22px;top:72px}.dashboard-kpis{grid-template-columns:repeat(2,minmax(0,1fr))}.dashboard-kpis article{min-height:145px;padding:17px}.dashboard-kpis strong{font-size:2.7rem}.dashboard-panel{padding:19px 16px}.priority-row{grid-template-columns:auto minmax(0,1fr) auto}.priority-signals{grid-column:2/-1;justify-content:flex-start}.dashboard-items-grid{grid-template-columns:1fr}.dashboard-worklist-head{flex-direction:column}.dashboard-item-filters{width:100%}.dashboard-empty{grid-template-columns:1fr;gap:20px;min-height:0}.dashboard-empty-mark{text-align:left}.dashboard-data-footer{flex-direction:column;align-items:flex-start}.dashboard-import-prompt{grid-template-columns:1fr;align-items:start}.dashboard-import-actions{justify-content:flex-start;max-width:none}.dashboard-home-hero,.dashboard-course-hero,.dashboard-section-heading,.dashboard-add-course-banner{flex-direction:column;align-items:flex-start}.dashboard-home-hero h1,.dashboard-course-hero h1{font-size:clamp(3rem,17vw,5rem)}.dashboard-course-cards{grid-template-columns:1fr}.dashboard-course-card{min-height:350px}.dashboard-course-nav{margin-inline:-22px;padding-inline:22px}.dashboard-course-nav button{margin-left:0}.dashboard-checklist-head{grid-template-columns:1fr}.checklist-total-progress{border-left:0;border-top:1px solid var(--line);padding:18px 0 0}.checklist-unit-toggle{grid-template-columns:auto minmax(0,1fr) auto}.checklist-unit-meter,.checklist-unit-percent{grid-column:2}.checklist-unit-chevron{grid-area:1/3/3}.checklist-skill-row{grid-template-columns:1fr;gap:16px}.dashboard-course-page .unit-progress-row{grid-template-columns:minmax(0,1fr) auto}.dashboard-course-page .unit-mastery-meter,.dashboard-course-page .unit-row-signals{grid-column:1/-1}.subject-picker-dialog{width:min(100% - 20px,860px);max-height:calc(100dvh - 20px)}.subject-picker-copy{padding:28px 20px 20px}.subject-picker-grid{grid-template-columns:1fr;padding-inline:20px}.subject-picker-actions{padding:18px 20px 22px}}@media (max-width:520px){.subject-picker-dialog{border-radius:22px 22px 0 0;width:100%;max-width:none;max-height:calc(100dvh - 12px);margin:auto 0 0}.subject-picker-actions{padding-bottom:calc(22px + env(safe-area-inset-bottom))}.dashboard-kpis{grid-template-columns:1fr}.dashboard-panel-head{flex-direction:column}.unit-progress-row{grid-template-columns:minmax(0,1fr) auto}.unit-mini-bar,.unit-progress-status{grid-row:2}}.panel-toggle{cursor:pointer;border:1px solid var(--line-strong);color:var(--ink-2);background:0 0;border-radius:100px;align-items:center;gap:7px;padding:8px 15px;font-size:12.5px;font-weight:600;transition:all .25s;display:inline-flex}.panel-toggle:hover{border-color:var(--ink);color:var(--ink)}.panel-toggle.on{background:var(--navy);border-color:var(--navy);color:var(--paper-on-navy)}.units{border-right:1px solid var(--line);height:calc(100vh - 73px);position:sticky;top:73px;overflow:hidden auto}.units.closed{border-right:none;overflow:hidden}.units-inner{width:280px;padding:36px 0}.units-head{padding:0 28px 8px}.units-head .code{font-family:var(--mono);color:var(--ink-3);letter-spacing:.12em;font-size:11px}.units-head h1{font-family:var(--serif);color:var(--ink);margin-top:4px;font-size:1.5rem;font-weight:600}.not-found-page{text-align:center;background:var(--paper);flex-direction:column;justify-content:center;align-items:center;gap:18px;min-height:100vh;padding:48px 24px;display:flex}.not-found-mark{color:var(--moss);font-family:var(--mono);letter-spacing:.24em;font-size:12px;font-weight:600}.not-found-page h1{color:var(--ink);font-family:var(--serif);font-size:clamp(2.4rem,7vw,5rem);line-height:1.05}.not-found-page p{max-width:520px;color:var(--ink-2)}.not-found-page .btn{margin-top:10px}.units-label{font-family:var(--sans);letter-spacing:.22em;text-transform:uppercase;color:var(--ink-3);padding:26px 28px 12px;font-size:10.5px;font-weight:600}.unit{text-align:left;cursor:pointer;width:100%;color:var(--ink-2);font-family:var(--sans);background:0 0;border:none;border-left:2px solid #0000;align-items:baseline;gap:14px;padding:13px 28px;font-size:14.5px;font-weight:500;transition:all .25s;display:flex}.unit .un{font-family:var(--mono);color:var(--ink-3);min-width:20px;font-size:11px}.unit .uc{font-family:var(--mono);color:var(--ink-3);margin-left:auto;font-size:11px}.unit:hover{color:var(--ink);background:#171b4009}.unit.active{color:var(--ink);border-left-color:var(--moss);background:var(--green-soft);font-weight:600}.unit.active .un,.unit.active .uc{color:var(--moss)}.crumb{color:var(--ink-3);cursor:pointer;font-size:13px;font-weight:500;font-family:var(--sans);background:0 0;border:none;align-items:center;gap:8px;margin-bottom:6px;text-decoration:none;transition:color .25s;display:inline-flex}.crumb:hover{color:var(--ink)}.problems{min-width:0;padding:40px 44px 100px}.problems-head h2{font-size:2.1rem}.problems-head .eyebrow{margin-bottom:12px}.problems-head p{color:var(--ink-2);margin-top:8px;font-size:14.5px}.problem{border:1px solid var(--line);background:var(--card);border-radius:14px;margin-top:26px;transition:border-color .3s,box-shadow .3s;overflow:hidden}.problem:hover{border-color:var(--line-strong);box-shadow:0 16px 34px -26px #171b404d}.problem-top{grid-template-columns:minmax(0,1fr) auto;align-items:flex-start;gap:12px 18px;padding:26px 30px 4px;display:grid}.problem-top-meta{flex-wrap:wrap;align-items:center;gap:14px;min-width:0;min-height:44px;display:flex}.ptag{font-family:var(--mono);letter-spacing:.06em;color:var(--bronze);background:var(--bronze-soft);border-radius:6px;padding:5px 11px;font-size:11px}.shared-tag{font-family:var(--mono);letter-spacing:.08em;text-transform:uppercase;color:var(--moss);border:1px solid color-mix(in srgb, var(--moss) 35%, transparent);border-radius:999px;padding:4px 9px;font-size:10px}.ptopic{color:var(--ink-3);margin-left:auto;font-size:12.5px}.problem-learning-actions{flex:none;align-items:center;gap:8px;display:flex;position:relative}.difficulty-picker{z-index:5;font-family:var(--sans);position:relative}.difficulty-picker[open]{z-index:15}.difficulty-picker>summary{border:1px solid var(--line-strong);background:var(--card);min-height:44px;color:var(--ink-2);cursor:pointer;border-radius:999px;align-items:center;gap:8px;padding:8px 13px;font-size:12.5px;font-weight:650;line-height:1;list-style:none;transition:border-color .2s,background .2s,color .2s;display:inline-flex}.difficulty-picker>summary::-webkit-details-marker{display:none}.difficulty-picker>summary:hover,.difficulty-picker[open]>summary{border-color:color-mix(in srgb, var(--bronze) 58%, transparent);background:var(--bronze-soft);color:var(--ink)}.difficulty-picker>summary:focus-visible,.bookmark-button:focus-visible,.difficulty-option:focus-visible,.difficulty-clear:focus-visible{outline:2px solid var(--navy);outline-offset:3px}.difficulty-bars{align-items:flex-end;gap:2px;width:15px;height:15px;display:inline-flex}.difficulty-bars span{background:var(--line-strong);border-radius:3px;width:3px}.difficulty-bars span:first-child{height:5px}.difficulty-bars span:nth-child(2){height:9px}.difficulty-bars span:nth-child(3){height:14px}.difficulty-bars-1 span:first-child,.difficulty-bars-2 span:nth-child(-n+2),.difficulty-bars-3 span{background:var(--bronze)}.difficulty-popover{border:1px solid var(--line-strong);background:var(--card);border-radius:14px;width:min(310px,100vw - 60px);padding:16px;position:absolute;top:calc(100% + 8px);right:-52px;box-shadow:0 22px 50px -24px #171b406b}.difficulty-popover-title{color:var(--ink);margin-bottom:11px;font-size:13px;font-weight:700}.difficulty-options{font-family:var(--sans);grid-template-columns:repeat(3,minmax(0,1fr));gap:7px;display:grid}.difficulty-option{border:1px solid var(--line);background:var(--paper);min-height:38px;color:var(--ink-2);font:600 11.5px/1.2 var(--sans);cursor:pointer;border-radius:9px;justify-content:center;align-items:center;gap:6px;padding:7px 8px;transition:border-color .2s,background .2s,color .2s;display:inline-flex}.difficulty-option:hover{border-color:var(--line-strong);color:var(--ink)}.difficulty-option.selected{border-color:var(--bronze);background:var(--bronze-soft);color:var(--ink)}.difficulty-option-dot{background:var(--ink-3);border-radius:50%;flex:none;width:7px;height:7px}.difficulty-option-1 .difficulty-option-dot{background:var(--moss)}.difficulty-option-2 .difficulty-option-dot{background:var(--bronze)}.difficulty-option-3 .difficulty-option-dot{background:var(--purple)}.difficulty-clear{color:var(--ink-3);text-underline-offset:3px;cursor:pointer;background:0 0;border:none;margin:11px auto 0;padding:2px 4px;font-size:11px;text-decoration:underline;display:block}.difficulty-clear-inline{grid-column:1/-1;justify-self:center;margin-top:4px}.learning-storage-warning{border:1px solid color-mix(in srgb, var(--bronze) 48%, var(--line));background:var(--bronze-soft);color:var(--ink-2);border-radius:10px;margin:0 0 22px;padding:10px 13px;font-size:12px;line-height:1.45}.learning-tooltip{font-family:var(--sans);display:inline-flex;position:relative}.bookmark-button{border:1px solid var(--line-strong);background:var(--card);min-width:44px;min-height:44px;color:var(--ink-2);cursor:pointer;transition:border-color .2s, background .2s, color .2s, transform .2s var(--ease);border-radius:999px;justify-content:center;align-items:center;gap:8px;padding:9px 12px;font-size:12.5px;font-weight:650;display:inline-flex}.bookmark-button:hover{border-color:var(--moss);color:var(--moss);transform:translateY(-1px)}.bookmark-button.active{border-color:var(--moss);background:var(--green-soft);color:var(--moss)}.bookmark-button.active svg{fill:currentColor}.learning-tooltip>[role=tooltip]{z-index:20;background:var(--navy);width:max-content;max-width:180px;color:var(--paper-on-navy);opacity:0;pointer-events:none;border-radius:7px;padding:6px 9px;font-size:11px;font-weight:600;line-height:1.25;transition:opacity .16s,transform .16s;position:absolute;bottom:calc(100% + 8px);right:0;transform:translateY(3px)}.learning-tooltip:hover>[role=tooltip],.learning-tooltip:focus-within>[role=tooltip]{opacity:1;transform:none}.learning-tooltip.compact>[role=tooltip]{top:calc(100% + 8px);bottom:auto}.problem.learning-focus,.guide-part.learning-focus{outline:3px solid color-mix(in srgb, var(--pistachio) 88%, var(--moss));outline-offset:5px;animation:1.2s ease-out learning-focus-pulse}@keyframes learning-focus-pulse{0%{outline-offset:12px}to{outline-offset:5px}}.problem-body{color:var(--ink);padding:14px 30px 24px;font-size:15.5px;line-height:1.75;overflow-x:auto}.problem-body p{max-width:68ch;margin:0 0 1.15rem}.problem-body .katex{font-size:1.05em}.problem-body p+p{margin-top:0}.problem-body .katex-display{background:var(--paper);border-left:2px solid var(--moss);border-radius:0 9px 9px 0;margin:1.45rem 0;padding:.85rem 1rem;overflow-x:auto}.problem-body h2,.problem-body h3,.problem-body h4{font-family:var(--sans);letter-spacing:.16em;text-transform:uppercase;color:var(--ink-3);margin:18px 0 8px;font-size:10.5px;font-weight:700}.problem-body ul,.problem-body ol{margin:6px 0 10px;padding-left:22px}.problem-body li{margin:5px 0;padding-left:4px}.problem-body li::marker{color:var(--moss);font-weight:600;font-family:var(--mono);font-size:.9em}.problem-body .problem-subparts{margin:8px 0 12px;padding-left:30px}.problem-body .problem-subparts>li{margin:8px 0;padding-left:7px}.problem-body .problem-subparts>li::marker{content:counter(list-item, lower-alpha) ") "}.problem-body .problem-subparts .markdown-content>:first-child{margin-top:0}.problem-body .problem-subparts .markdown-content>:last-child{margin-bottom:0}.problem-hint{border:1px solid color-mix(in srgb, var(--purple) 24%, transparent);border-left:3px solid var(--purple);background:var(--purple-soft);border-radius:12px;grid-template-columns:auto minmax(0,1fr);gap:12px;max-width:68ch;margin:18px 0 4px;padding:16px 18px;display:grid}.problem-hint-icon{border:1px solid color-mix(in srgb, var(--purple) 38%, transparent);background:color-mix(in srgb, var(--card) 72%, transparent);width:28px;height:28px;color:var(--purple);border-radius:50%;place-items:center;margin-top:1px;display:grid}.problem-hint-icon svg{fill:none;stroke:currentColor;stroke-width:1.9px;stroke-linecap:round;width:18px;height:18px;overflow:visible}.problem-hint-icon .problem-hint-icon-dot{fill:currentColor;stroke:none}.problem-hint-copy{min-width:0}.problem-hint-title{color:var(--purple);letter-spacing:.02em;margin-bottom:4px;font-size:13px;font-weight:700}.problem-hint .markdown-content>:first-child{margin-top:0}.problem-hint .markdown-content>:last-child{margin-bottom:0}.problem-hint .katex-display{border-left-color:var(--purple);background:color-mix(in srgb, var(--card) 58%, transparent)}.problem-actions{flex-wrap:wrap;align-items:center;gap:12px;padding:0 30px 24px;display:flex}.problem-study-link{border:1px solid color-mix(in srgb, var(--moss) 48%, var(--line));background:var(--green-soft);color:var(--moss);border-radius:100px;align-items:center;gap:8px;margin-left:auto;padding:10px 17px;font-size:13.5px;font-weight:650;line-height:1;text-decoration:none;transition:border-color .2s,background .2s,color .2s,transform .2s;display:inline-flex}.problem-study-link svg{fill:none;stroke:currentColor;stroke-width:1.8px;stroke-linecap:round;stroke-linejoin:round;width:15px;height:15px}.problem-study-link:hover{border-color:var(--moss);background:color-mix(in srgb, var(--green-soft) 72%, var(--card));color:var(--ink);transform:translateY(-1px)}.problem-study-link:focus-visible{outline:2px solid var(--moss);outline-offset:3px}.problem-study-link+.ask-btn{margin-left:0}.toggle-btn{cursor:pointer;border:1px solid var(--line-strong);color:var(--ink-2);background:0 0;border-radius:100px;align-items:center;gap:9px;padding:10px 20px;font-size:13.5px;font-weight:600;transition:all .25s;display:inline-flex}.toggle-btn:hover{border-color:var(--ink);color:var(--ink)}.toggle-btn .car{transition:transform .35s var(--ease);font-size:10px}.toggle-btn.open{border-color:var(--moss);color:var(--moss);background:var(--green-soft)}.toggle-btn.open .car{transform:rotate(180deg)}.ask-btn{cursor:pointer;background:var(--navy);border:1px solid var(--navy);color:var(--paper-on-navy);transition:all .25s var(--ease);border-radius:100px;align-items:center;gap:9px;margin-left:auto;padding:10px 20px;font-size:13.5px;font-weight:600;display:inline-flex}.ask-btn:hover{background:var(--navy-2);transform:translateY(-1px)}.ask-btn:focus-visible{outline:2px solid var(--navy);outline-offset:3px}.guide h2.learning-focus,.guide h3.learning-focus{outline:3px solid color-mix(in srgb, var(--pistachio) 88%, var(--moss));outline-offset:6px;border-radius:4px;animation:1.2s ease-out learning-focus-pulse}.problem-report{border:1px solid var(--line);background:var(--paper);color:var(--ink-3);border-radius:9px;justify-content:space-between;align-items:center;gap:14px;margin:24px 0 0;padding:11px 14px;font-size:12px;display:flex}.problem-report a{color:var(--ink-2);flex:none;font-weight:650;text-decoration:none}.problem-report a:hover{color:var(--moss)}.contact-honeypot{width:1px;height:1px;position:absolute;left:-10000px;overflow:hidden}.optional{color:var(--ink-3);font-weight:400}.solution{background:var(--paper);border:1px solid var(--line);border-radius:10px;margin:0 30px 26px;animation:.4s fadein}.sol-pane{color:var(--ink-2);padding:18px 26px 24px;font-size:14px;line-height:1.7;overflow-x:auto}.sol-pane strong,.sol-pane .katex{color:var(--ink)}.sol-label{font-family:var(--mono);letter-spacing:.2em;text-transform:uppercase;color:var(--moss);padding:20px 26px 0;font-size:10.5px;font-weight:500}.sol-fasit{flex-wrap:wrap;align-items:baseline;gap:12px;margin-bottom:14px;display:flex}.sol-fasit+*{border-top:1px solid var(--line);padding-top:14px}.sol-fasit-k{font-family:var(--mono);letter-spacing:.16em;text-transform:uppercase;color:var(--moss);flex:none;font-size:10.5px}.sol-fasit-v{color:var(--ink);font-weight:500}.sol-fasit-v p{margin:0}.chat-note{color:var(--ink-3);font-size:10.5px;font-family:var(--mono);letter-spacing:.04em;margin:8px 2px 0}.units-note{border-top:1px solid var(--line);color:var(--ink-3);margin:28px 26px 0;padding-top:20px;font-size:12px;line-height:1.6}.units-privacy{color:var(--ink-2);text-underline-offset:3px;margin-top:10px;display:block}.msg .kilde{font-family:var(--mono);letter-spacing:.1em;color:var(--ink-3);margin-bottom:11px;font-size:10.5px}.empty-note{border:1px dashed var(--line-strong);text-align:center;color:var(--ink-3);border-radius:14px;margin-top:26px;padding:60px 30px}.load-more{margin:30px auto 0;display:block}.chat{border-left:1px solid var(--line);background:var(--card);height:calc(100vh - 73px);position:sticky;top:73px;overflow:hidden}.chat.closed{border-left:none}.chat-inner{flex-direction:column;min-width:400px;height:100%;display:flex}.chat-head{border-bottom:1px solid var(--line);align-items:center;gap:12px;padding:26px 28px 18px;display:flex}.chat-head .dot{background:var(--moss);border-radius:50%;width:8px;height:8px;animation:2.4s infinite pulse}@keyframes pulse{50%{opacity:.35}}.chat-head h4{font-family:var(--serif);color:var(--ink);font-size:1.15rem;font-weight:600}.ai-badge{border:1px solid var(--bronze);min-height:20px;color:var(--bronze);font-family:var(--mono);letter-spacing:.1em;border-radius:999px;align-items:center;padding:2px 7px;font-size:9px;font-weight:700;display:inline-flex}.chat-head .plib-open{border:1px solid var(--line-strong);color:var(--ink-2);letter-spacing:.04em;cursor:pointer;background:0 0;border-radius:100px;margin-left:auto;padding:7px 14px;font-size:11.5px;font-weight:500;transition:all .25s}.chat-head .plib-open:hover{border-color:var(--ink);color:var(--ink)}.chat-head .plib-open:disabled{cursor:not-allowed;opacity:.45}.chat-mobile-close{border:1px solid var(--line-strong);background:var(--paper);color:var(--ink);font-family:var(--sans);cursor:pointer;border-radius:999px;align-items:center;gap:6px;padding:6px 11px;font-size:12px;font-weight:600;display:inline-flex}.chat-mobile-close span{font-size:17px;line-height:.8}.chat-body{flex-direction:column;flex:1;gap:16px;padding:24px 28px;display:flex;overflow-y:auto}.tutor-lock{border:1px solid var(--line-strong);background:var(--paper);border-radius:16px;margin:auto 0;padding:32px 28px;position:relative;overflow:hidden}.tutor-lock-mark{color:var(--ink);opacity:.06;pointer-events:none;font-size:150px;font-weight:200;line-height:1;position:absolute;bottom:-55px;right:8px}.tutor-lock h5{font-family:var(--serif);color:var(--ink);margin:0 0 12px;font-size:1.4rem;position:relative}.tutor-lock p{color:var(--ink-2);margin:0 0 20px;font-size:13.5px;line-height:1.65;position:relative}.tutor-lock a{color:var(--bronze);text-underline-offset:3px;font-size:12px;font-weight:600;position:relative}.msg{max-width:94%;animation:msgIn .45s var(--ease);border-radius:16px;padding:15px 19px;font-size:14px;line-height:1.65;overflow-x:auto}@keyframes msgIn{0%{opacity:0;transform:translateY(12px)}to{opacity:1;transform:none}}.msg.assistant{background:var(--paper);border:1px solid var(--line);color:var(--ink-2);border-bottom-left-radius:5px;align-self:flex-start}.msg.user{background:var(--navy);color:var(--paper-on-navy);white-space:pre-wrap;border-bottom-right-radius:5px;align-self:flex-end}.markdown-content{min-width:0}.markdown-content table{border-collapse:collapse;border-spacing:0;width:max-content;max-width:100%;margin:1.35rem 0 1.7rem;font-size:.96em;display:block;overflow-x:auto}.markdown-content th,.markdown-content td{text-align:left;vertical-align:top;border:1px solid var(--line-strong);min-width:8rem;padding:.8rem 1rem}.markdown-content th{color:var(--navy);background:color-mix(in srgb, var(--paper-2) 72%, white);font-weight:700}.markdown-content tr:nth-child(2n) td{background:color-mix(in srgb, var(--paper-2) 40%, white)}.msg.assistant strong,.sol-pane strong{color:var(--ink)}.msg.assistant .katex,.sol-pane .katex{color:var(--ink);font-size:1.04em}.msg.assistant p{margin:0 0 9px}.msg.assistant>:last-child,.msg.assistant p:last-child{margin-bottom:0}.msg.assistant h1,.msg.assistant h2,.msg.assistant h3,.msg.assistant h4,.sol-pane h1,.sol-pane h2,.sol-pane h3,.sol-pane h4{font-family:var(--sans);letter-spacing:.16em;text-transform:uppercase;color:var(--ink);margin:16px 0 7px;font-size:10.5px;font-weight:700}.msg.assistant h1:first-child,.msg.assistant h2:first-child,.msg.assistant h3:first-child{margin-top:2px}.msg.assistant ul,.msg.assistant ol,.sol-pane ul,.sol-pane ol{margin:4px 0 10px;padding-left:22px}.msg.assistant li,.sol-pane li{margin:4px 0}.msg.assistant li::marker{color:var(--moss);font-weight:600;font-family:var(--mono);font-size:.9em}.sol-pane li::marker{color:var(--moss);font-weight:600;font-family:var(--mono);font-size:.9em}.msg.assistant .katex-display,.sol-pane .katex-display{margin:10px 0;padding:3px 0;overflow:auto hidden}.msg.assistant code,.sol-pane code{font-family:var(--mono);background:var(--paper-2);border:1px solid var(--line);border-radius:5px;padding:1px 5px;font-size:.88em}.msg.assistant pre,.sol-pane pre{background:var(--paper-2);border:1px solid var(--line);border-radius:8px;margin:8px 0 10px;padding:10px 12px;overflow-x:auto}.msg.assistant pre code,.sol-pane pre code{background:0 0;border:none;padding:0}.msg.assistant hr,.sol-pane hr{border:none;border-top:1px solid var(--line);margin:12px 0}.msg.assistant blockquote,.sol-pane blockquote{border-left:2px solid var(--moss);color:var(--ink-3);margin:8px 0 10px;padding-left:12px}.msg.thinking{color:var(--ink-3);font-style:italic}.msg.error-text{color:#a04432;border-color:#b43c2866}.sugg-label{font-family:var(--sans);letter-spacing:.2em;text-transform:uppercase;color:var(--ink-3);margin-top:6px;font-size:10px;font-weight:600}.sugg{text-align:left;border:1px solid var(--line);color:var(--ink-2);cursor:pointer;background:0 0;border-radius:12px;padding:12px 16px;font-size:13.5px;line-height:1.5;transition:all .25s}.sugg:hover{border-color:var(--moss);color:var(--ink);background:var(--green-soft)}.chat-input{border-top:1px solid var(--line);padding:18px 24px 24px}.tutor-controls{justify-content:flex-end;align-items:center;gap:10px;margin-bottom:10px;display:flex}.mode-switch{border:1px solid var(--line);background:var(--paper-2);border-radius:10px;min-width:0;padding:3px;display:flex}.mode-switch button{color:var(--ink-3);font-family:var(--sans);white-space:nowrap;cursor:pointer;background:0 0;border:none;border-radius:7px;padding:6px 8px;font-size:10.5px;font-weight:600;transition:background .2s,color .2s,box-shadow .2s}.mode-switch button.active{background:var(--card);color:var(--ink);box-shadow:0 1px 4px #171b401f}.mode-switch button:disabled{cursor:default;opacity:.6}.tutor-disabled-note{text-align:center;margin:0}.chat-input .box{background:var(--paper);border:1px solid var(--line-strong);border-radius:16px;align-items:flex-end;gap:10px;padding:12px 14px;transition:border-color .25s;display:flex}.chat-input .box:focus-within{border-color:var(--navy)}.chat-input textarea{resize:none;color:var(--ink);font-family:var(--sans);background:0 0;border:none;outline:none;flex:1;max-height:120px;font-size:14px;line-height:1.5}.chat-input textarea::placeholder{color:var(--ink-3)}.send{background:var(--navy);width:36px;height:36px;color:var(--paper-on-navy);cursor:pointer;border:none;border-radius:11px;flex-shrink:0;place-items:center;transition:background .25s,transform .25s;display:grid}.send:hover{background:var(--navy-2);transform:translateY(-1px)}.send:disabled{opacity:.45;cursor:default}@media (max-width:460px){.tutor-controls{flex-direction:column;align-items:flex-start}.mode-switch{width:100%}.mode-switch button{flex:1}}.overlay{z-index:100;-webkit-backdrop-filter:blur(5px);backdrop-filter:blur(5px);background:#171b4066;justify-content:center;align-items:center;padding:24px;animation:.3s fadein;display:flex;position:fixed;inset:0}.plib{background:var(--card);border:1px solid var(--line);width:min(680px,100%);max-height:82vh;animation:msgIn .45s var(--ease);border-radius:20px;padding:38px 40px;overflow-y:auto;box-shadow:0 40px 80px -30px #171b4073}.plib h3{font-family:var(--serif);color:var(--ink);font-size:1.65rem;font-weight:600}.plib>p{color:var(--ink-2);margin-top:8px;font-size:14px}.plib-cat{font-family:var(--sans);letter-spacing:.22em;text-transform:uppercase;color:var(--moss);margin:30px 0 12px;font-size:10.5px;font-weight:600}.plib-item{text-align:left;background:var(--paper);border:1px solid var(--line);width:100%;color:var(--ink-2);cursor:pointer;border-radius:12px;margin-bottom:9px;padding:14px 18px;font-size:13.5px;line-height:1.55;transition:all .25s;display:block}.plib-item:hover{border-color:var(--moss);color:var(--ink);transform:translate(4px)}.plib-close{float:right;background:var(--paper);border:1px solid var(--line-strong);width:34px;height:34px;color:var(--ink-2);cursor:pointer;border-radius:50%;font-size:15px;position:sticky;top:0}.plib-close:hover{color:var(--ink);border-color:var(--ink)}.chat-fab{z-index:70;background:var(--navy);width:60px;height:60px;color:var(--paper-on-navy);cursor:pointer;transition:transform .25s var(--ease);border:none;border-radius:50%;place-items:center;display:none;position:fixed;bottom:28px;right:28px;box-shadow:0 16px 40px -10px #14213880}.chat-fab:hover{transform:scale(1.07)}@media (max-width:1180px){.course-shell{grid-template-columns:var(--col-units,250px) minmax(0, 1fr)}.chat{display:none}.chat.mobile-open{z-index:60;background:var(--card);display:flex;position:fixed;inset:73px 0 0}.chat.mobile-open .chat-inner{width:100%;min-width:0}.chat-fab{display:grid}}@media (max-width:860px){.site-nav{padding:16px 22px}.nav-links{gap:9px}.nav-links a:not(.btn):not(.nav-personal-link){display:none}.section,.how-band-inner{padding:90px 22px}.closing-inner{padding:110px 22px 100px}.course-shell{grid-template-columns:1fr}.units{border-right:none;border-bottom:1px solid var(--line);height:auto;padding-bottom:10px;position:static}.units.closed{display:none}.units-inner{width:100%;padding:8px 0 0}.units .units-head,.units .units-label,.units .units-note{display:none}.unit-list{padding:0 16px;display:flex;overflow-x:auto}.unit{white-space:nowrap;border-bottom:2px solid #0000;border-left:none;padding:12px 16px}.unit.active{border-bottom-color:var(--moss);border-left:none}.unit .uc{display:none}.problems{padding:30px 22px 120px}.problem-report{flex-direction:column;align-items:flex-start}.hero-stats{grid-template-columns:1fr;width:100%;max-width:340px}.stat{border-right:none;border-bottom:1px solid var(--line);padding:18px 0}.stat:last-child{border-bottom:none}.steps{grid-template-columns:1fr;gap:44px}.steps:before{display:none}.stack-sticky{grid-template-columns:1fr;align-content:center;gap:28px;padding:80px 22px 30px}.stack-fig{order:-1}.stack-fig svg{width:min(300px,80vw)}.layer-desc{min-height:120px}.site-footer{flex-direction:column;gap:14px}}@media (max-width:600px){.site-nav .nav-personal-link,.site-nav .panel-toggle{justify-content:center;width:40px;height:40px;padding:0}.site-nav .nav-personal-link span{display:none}.site-nav .panel-toggle{font-size:0;overflow:hidden}.problem-top{grid-template-columns:minmax(0,1fr);padding:20px 20px 4px}.problem-top-meta{flex-basis:100%;min-height:0}.problem-top-meta .ptopic{margin-left:0}.problem-learning-actions{justify-content:flex-end;width:100%}.problem-body,.problem-actions{padding-inline:20px}}.section-tabs{border-bottom:1px solid var(--line);flex-wrap:wrap;gap:2px;margin:0 0 26px;display:flex}.section-tab{appearance:none;font-family:var(--sans);color:var(--ink-2);cursor:pointer;transition:color .2s var(--ease);background:0 0;border:none;padding:10px 14px 13px;font-size:14px;font-weight:600;position:relative}.section-tab:hover,.section-tab.active{color:var(--ink)}.section-tab.active:after{content:"";background:var(--moss);border-radius:2px 2px 0 0;height:2px;position:absolute;bottom:-1px;left:12px;right:12px}.ref-group{margin-bottom:30px}.ref-group-h{font-family:var(--sans);text-transform:uppercase;letter-spacing:.09em;color:var(--bronze);border-bottom:1px solid var(--line);margin:0 0 12px;padding-bottom:8px;font-size:12px;font-weight:600}.ref-grid{grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:12px;display:grid}.ref-card{background:var(--card);border:1px solid var(--line);color:var(--ink);transition:border-color .2s var(--ease), transform .2s var(--ease), box-shadow .2s var(--ease);border-radius:12px;align-items:center;gap:12px;padding:14px 16px;text-decoration:none;display:flex}.ref-card:hover{border-color:var(--line-strong);transform:translateY(-1px);box-shadow:0 6px 20px #171b400f}.ref-ext{font-family:var(--mono);text-transform:uppercase;letter-spacing:.04em;color:var(--moss);background:var(--green-soft);border-radius:6px;flex:none;padding:5px 7px;font-size:10px;font-weight:500}.ref-title{text-overflow:ellipsis;flex:1;font-size:14px;line-height:1.35;overflow:hidden}.ref-open{font-family:var(--sans);color:var(--bronze);opacity:0;transition:opacity .2s var(--ease);flex:none;font-size:12.5px;font-weight:600}.ref-card:hover .ref-open{opacity:1}.ref-card:focus-visible{outline:2px solid var(--navy);outline-offset:2px}.ref-card:focus-visible .ref-open{opacity:1}.code-learning-page{grid-template-columns:minmax(0,1fr);gap:24px;width:100%;max-width:1040px;display:grid}.code-guide{border:1px solid var(--line);background:var(--card);color:#171b40e6;width:100%;min-width:0;font-family:var(--serif);border-radius:18px;padding:clamp(26px,3.4vw,46px);font-size:17px;line-height:1.72}.code-guide .markdown-content>:first-child{margin-top:0}.code-guide .markdown-content>:last-child{margin-bottom:0}.code-guide h2{border-top:1px solid var(--line);color:var(--navy);font-family:var(--serif);letter-spacing:-.01em;margin:42px 0 14px;padding-top:25px;scroll-margin-top:110px;font-size:1.42rem;font-weight:500;line-height:1.25}.code-guide h2:first-of-type{border-top:0;margin-top:4px;padding-top:0}.code-guide h3{color:var(--bronze);font-family:var(--serif);margin:28px 0 10px;font-size:1.08rem;font-weight:600}.code-guide p{margin:0 0 15px}.code-guide ul,.code-guide ol{margin:4px 0 18px;padding-inline-start:24px}.code-guide li{margin-bottom:7px}.code-guide li::marker{color:var(--moss)}.code-guide :not(pre)>code{background:var(--bronze-soft);font-family:var(--mono);border-radius:5px;padding:1.5px 5px;font-size:.88em}.code-guide pre{background:var(--navy);color:#f8f7ef;max-width:100%;font:13.5px/1.7 var(--mono);tab-size:4;border:1px solid #ffffff1f;border-radius:13px;margin:20px 0 24px;padding:19px 21px;overflow-x:auto;box-shadow:0 12px 28px #171b401f}.code-guide pre code{color:inherit;font:inherit;background:0 0;border:0;padding:0}.code-guide pre:focus-visible{outline:3px solid var(--bronze);outline-offset:3px}.code-sources{border:1px solid var(--line);background:color-mix(in srgb, var(--paper) 78%, var(--card));border-radius:15px;padding:20px}.code-sources>p{color:var(--ink-3);margin:-2px 0 15px;font-size:13px;line-height:1.5}.code-empty-state{border:1px solid var(--line);background:var(--card);border-radius:15px;align-items:flex-start;gap:15px;padding:22px;display:flex}.code-empty-state>span{background:var(--green-soft);width:30px;height:30px;color:var(--moss);font-family:var(--sans);border-radius:50%;flex:none;place-items:center;font-weight:750;display:grid}.code-empty-state strong{color:var(--navy);font-family:var(--serif);margin-bottom:4px;font-size:1.03rem;display:block}.code-empty-state p{color:var(--ink-3);margin:0;font-size:13.5px;line-height:1.55}.code-guide blockquote,.formula-pane blockquote{border:1px solid var(--line);border-left:3px solid var(--bronze);background:var(--bronze-soft);color:var(--ink-2);font-family:var(--sans);border-radius:11px;margin:0 0 24px;padding:14px 17px;font-size:13px;line-height:1.55}.code-guide blockquote>:last-child,.formula-pane blockquote>:last-child{margin-bottom:0}.course-language-row{width:100%;max-width:1040px;color:var(--ink-3);justify-content:flex-end;align-items:center;gap:10px 14px;margin:2px 0 18px;font-size:11px;font-weight:650;display:flex}.course-language-switch{border:1px solid var(--line-strong);background:var(--card);border-radius:999px;gap:3px;padding:3px;display:inline-flex;box-shadow:0 6px 18px #171b400d}.course-language-switch button{min-height:34px;color:var(--ink-2);cursor:pointer;font:650 11.5px/1 var(--sans);transition:background .16s var(--ease), color .16s var(--ease);background:0 0;border:0;border-radius:999px;padding:6px 14px}.course-language-switch button:hover{color:var(--navy)}.course-language-switch button.active{background:var(--navy);color:#fff}.course-language-switch button:focus-visible{outline:3px solid var(--bronze);outline-offset:2px}.svd-exam-empty{border:1px solid var(--line);border-left:3px solid var(--bronze);background:var(--card);border-radius:15px;align-items:flex-start;gap:18px;width:100%;max-width:760px;padding:22px;display:flex}.svd-exam-empty>span{background:var(--bronze-soft);width:42px;height:42px;color:var(--bronze);font:700 11px/1 var(--mono);border-radius:50%;flex:none;place-items:center;display:grid}.svd-exam-empty strong{color:var(--navy);font-family:var(--serif);margin:1px 0 7px;font-size:1.08rem;display:block}.svd-exam-empty p{max-width:66ch;color:var(--ink-2);margin:0 0 16px;font-size:13.5px;line-height:1.6}.guide,.formula-pane{background:var(--card);border:1px solid var(--line);color:#171b40e6;width:100%;max-width:1040px;font-family:var(--serif);letter-spacing:.002em;border-radius:18px;padding:clamp(26px,3.4vw,46px);font-size:17px;line-height:1.78}.guide>:first-child,.formula-pane>:first-child{margin-top:0}.guide h1,.formula-pane h1{font-family:var(--serif);letter-spacing:-.015em;color:var(--navy);margin:0 0 6px;font-size:clamp(1.7rem,2.6vw,2.1rem);font-weight:500;line-height:1.15}.guide h2,.formula-pane h2{font-family:var(--serif);letter-spacing:-.01em;color:var(--navy);border-top:1px solid var(--line);margin:44px 0 14px;padding-top:26px;scroll-margin-top:110px;font-size:1.44rem;font-weight:500;line-height:1.25}.guide h2:first-of-type,.formula-pane h2:first-of-type{border-top:none;margin-top:6px;padding-top:0}.guide h3,.formula-pane h3{font-family:var(--serif);text-transform:none;letter-spacing:0;color:var(--bronze);margin:30px 0 10px;scroll-margin-top:110px;font-size:1.08rem;font-weight:600}.guide p,.formula-pane p{margin:0 0 15px}.guide strong,.formula-pane strong{color:var(--navy);font-weight:650}.guide em,.formula-pane em{color:#171b40a8;font-style:italic}.guide ul,.guide ol,.formula-pane ul,.formula-pane ol{margin:4px 0 16px;padding-inline-start:22px;list-style-position:outside}.guide li,.formula-pane li{margin:0 0 7px}.guide li::marker{color:var(--moss)}.formula-pane li::marker{color:var(--moss)}.guide hr,.formula-pane hr{background:var(--line);border:none;height:1px;margin:36px 0}.guide a,.formula-pane a{color:var(--bronze);text-underline-offset:2px;text-decoration:underline;text-decoration-thickness:1px}.guide code,.formula-pane code{font-family:var(--mono);background:var(--bronze-soft);border-radius:5px;padding:1.5px 5px;font-size:.88em}.guide .katex-display,.formula-pane .katex-display{margin:18px 0;padding:2px 0;overflow:auto hidden}.guide .katex,.formula-pane .katex{font-size:1.03em}.guide h2[id],.guide h3[id]{scroll-margin-top:182px}.guide-toc{z-index:6;border:1px solid var(--line);background:color-mix(in srgb, var(--card) 94%, transparent);-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);font-family:var(--sans);border-radius:12px;margin:-12px -14px 28px;padding:12px 14px;position:sticky;top:88px;box-shadow:0 8px 22px #171b400f}.guide-toc>span{color:var(--ink-3);letter-spacing:.16em;text-transform:uppercase;margin-bottom:7px;font-size:10px;font-weight:700;display:block}.guide-toc>div{scrollbar-width:thin;gap:7px;padding-bottom:2px;display:flex;overflow-x:auto}.guide-toc a{border:1px solid var(--line);background:var(--paper);color:var(--ink-2);border-radius:999px;flex:none;padding:5px 10px;font-size:11.5px;line-height:1.2;text-decoration:none}.guide-toc a:hover{border-color:var(--moss);color:var(--ink)}.guide-callout,.guide-proof{border:1px solid var(--line);border-left:3px solid var(--moss);background:var(--green-soft);border-radius:12px;margin:24px 0;padding:17px 20px}.guide-callout.funfact{border-left-color:var(--purple);background:var(--purple-soft)}.guide-callout-title{color:var(--navy);font-family:var(--serif);margin-bottom:8px;font-size:1.02rem;font-weight:600}.guide-callout .markdown-content>:last-child,.guide-proof-body .markdown-content>:last-child{margin-bottom:0}.guide-callout .markdown-content>ul,.guide-callout .markdown-content>ol{margin-top:8px}.guide-proof{background:var(--paper);padding:0}.guide-proof>summary{cursor:pointer;color:var(--navy);font-family:var(--serif);justify-content:space-between;align-items:center;gap:12px;padding:15px 19px;font-weight:600;list-style:none;display:flex}.guide-proof>summary::-webkit-details-marker{display:none}.guide-proof>summary:after{content:"+";font-family:var(--sans);color:var(--moss);font-size:18px}.guide-proof[open]>summary:after{content:"−"}.guide-proof-body{border-top:1px solid var(--line);background:var(--card);border-radius:0 0 11px 11px;padding:18px 20px}.guide-toggle{border:1px solid color-mix(in srgb, var(--purple) 30%, var(--line));background:linear-gradient(135deg, var(--purple-soft), var(--card) 72%);border-radius:14px;margin:24px 0;overflow:hidden;box-shadow:0 10px 28px #171b400e}.guide-toggle>summary{cursor:pointer;min-height:58px;color:var(--navy);font-family:var(--sans);letter-spacing:.015em;justify-content:space-between;align-items:center;gap:14px;padding:15px 19px;font-size:13px;font-weight:750;list-style:none;display:flex}.guide-toggle>summary::-webkit-details-marker{display:none}.guide-toggle>summary:before{content:"REP";background:var(--purple);color:#fff;font-family:var(--mono);letter-spacing:.12em;border-radius:999px;flex:none;padding:4px 8px;font-size:8.5px}.guide-toggle>summary:after{content:"+";color:var(--purple);margin-left:auto;font-size:20px;font-weight:500}.guide-toggle[open]>summary:after{content:"−"}.guide-toggle-body{border-top:1px solid color-mix(in srgb, var(--purple) 20%, var(--line));background:color-mix(in srgb, var(--card) 90%, var(--purple-soft));padding:20px 22px}.guide-toggle-body .markdown-content>:last-child{margin-bottom:0}.guide-intuition{border-left:3px solid var(--moss);color:var(--moss);font-family:var(--serif);margin:-10px 18px 26px;padding:4px 0 4px 16px;font-size:1rem;font-style:italic;line-height:1.62}.guide-intuition .markdown-content>:first-child{margin-top:0}.guide-intuition .markdown-content>:last-child{margin-bottom:0}.guide-part{scroll-margin-top:112px}.guide-reflection{border:1px solid var(--line-strong);background:color-mix(in srgb, var(--paper) 82%, var(--card));color:var(--ink);font-family:var(--sans);border-radius:15px;gap:18px;margin:28px 0 10px;padding:20px;line-height:1.45;display:grid}.guide-reflection-head,.guide-reflection-rating,.guide-part-actions{flex-wrap:wrap;justify-content:space-between;align-items:center;gap:14px 20px;display:flex}.guide-reflection-head strong{color:var(--navy);font-family:var(--serif);font-size:1.05rem;font-weight:600;display:block}.guide-reflection-kicker{color:var(--bronze);font-family:var(--mono);letter-spacing:.14em;text-transform:uppercase;margin-bottom:2px;font-size:9.5px;font-weight:600;display:block}.guide-reflection-rating{border-top:1px solid var(--line);padding-top:16px}.guide-reflection-rating>span,.guide-note-field>span{color:var(--ink-2);font-size:12.5px;font-weight:650}.guide-note-field{gap:7px;display:grid}.guide-note-field textarea{resize:vertical;border:1px solid var(--line-strong);background:var(--card);width:100%;min-height:82px;color:var(--ink);font:13px/1.55 var(--sans);border-radius:10px;padding:11px 13px}.guide-note-field textarea::placeholder{color:var(--ink-3)}.guide-note-field textarea:focus{outline:2px solid var(--navy);outline-offset:2px}.guide-note-privacy{color:var(--ink-3);font-size:10.5px;line-height:1.45}.guide-part-actions{border-top:1px solid var(--line);padding-top:16px}.guide-part-actions>span{color:var(--ink-3);font-size:11px}.guide-part-ask{width:min(240px,100%);min-height:44px;font-family:var(--sans);justify-content:space-between;margin-left:0;padding:9px 18px}.guide-visual-pair{flex-wrap:wrap;align-items:flex-start;gap:18px;margin:24px 0 30px;display:flex}.guide-visual-main,.guide-visual-side{min-width:0}.guide-visual-main{flex:1.35 430px}.guide-visual-side{flex:.85 300px}.guide-visual-main .guide-figure{max-width:none;margin:0}.guide-visual-main .markdown-content>p{margin:0}.guide-visual-side{border:1px solid var(--line);border-left:3px solid var(--bronze);background:var(--paper);font-family:var(--serif);border-radius:12px;padding:19px 21px;font-size:16.5px;line-height:1.58}.guide-visual-side-title{color:var(--navy);font-family:var(--serif);margin-bottom:12px;font-size:1.08rem;font-weight:600}.guide-visual-side .markdown-content>:first-child{margin-top:0}.guide-visual-side .markdown-content>:last-child{margin-bottom:0}.guide-visual-side .markdown-content table{table-layout:fixed;width:100%;margin:0 0 15px;font-size:.96rem;display:table;overflow:visible}.guide-visual-side .markdown-content th,.guide-visual-side .markdown-content td{text-align:center;min-width:0;padding:8px 9px}.guide-oppg{background:var(--paper);border:1px solid var(--line);border-left:2px solid var(--moss);border-radius:12px;margin:26px 0;padding:18px 22px}.guide-oppg-q{font-size:15.5px}.guide-oppg-q>:first-child{margin-top:0}.guide-oppg-q p:last-child{margin-bottom:0}.guide-sol{margin-top:14px}.guide-sol>summary{cursor:pointer;font-family:var(--sans);letter-spacing:.02em;color:var(--moss);background:var(--green-soft);-webkit-user-select:none;user-select:none;transition:background .2s var(--ease);border-radius:999px;align-items:center;gap:7px;padding:6px 13px;font-size:12px;font-weight:600;list-style:none;display:inline-flex}.guide-sol>summary:hover{background:#d9dd9a8c}.guide-sol>summary::-webkit-details-marker{display:none}.guide-sol>summary:after{content:"▾";transition:transform .2s var(--ease);font-size:9px}.guide-sol[open]>summary:after{transform:rotate(180deg)}.guide-sol-body{background:var(--card);border:1px solid var(--line);border-radius:10px;margin-top:14px;padding:16px 18px;font-size:15px}.guide-sol-body>:first-child{margin-top:0}.guide-sol-body p:last-child{margin-bottom:0}.guide-matte4c h2{border:1px solid color-mix(in srgb, var(--moss) 24%, var(--line));border-left:5px solid var(--moss);background:linear-gradient(105deg, var(--green-soft), var(--card) 78%);border-radius:14px;padding:18px 20px;box-shadow:0 10px 28px #171b400b}.guide-matte4c h2:first-of-type{border-top:1px solid color-mix(in srgb, var(--moss) 24%, var(--line));padding-top:18px}.guide-matte4c h3{color:var(--navy);align-items:center;gap:9px;display:flex}.guide-matte4c h3:before{content:"";background:linear-gradient(90deg, var(--purple), var(--logo-gold));border-radius:999px;width:18px;height:4px}.guide-matte4c .katex-display{border:1px solid color-mix(in srgb, var(--navy) 12%, var(--line));background:color-mix(in srgb, var(--paper-2) 44%, var(--card));border-radius:12px;padding:13px 15px}.guide-matte4c .katex{font-size:1.08em}.guide-matte4c .guide-oppg{border-left:4px solid var(--purple);background:linear-gradient(130deg, var(--purple-soft), var(--card) 62%);box-shadow:0 12px 30px #171b400e}.guide-matte4c .guide-sol>summary{background:var(--purple);color:#fff}.guide-matte4c .guide-sol>summary:hover{background:color-mix(in srgb, var(--purple) 88%, var(--navy))}.guide-matte4c .guide-visual-pair{grid-template-columns:minmax(0,1fr);gap:14px;display:grid}.guide-matte4c .guide-visual-main,.guide-matte4c .guide-visual-side{width:100%}.guide-matte4c .guide-visual-side{background:linear-gradient(110deg, var(--bronze-soft), var(--card) 74%);border-left-width:5px}.guide-matte4c .guide-figure{max-width:100%}.guide-matte4c .guide-figure-scroll{overflow-x:auto}.guide-matte4c .guide-figure img{background:linear-gradient(145deg, #fff, var(--paper));min-width:760px;padding:10px}.guide-matte4c .markdown-content th{background:color-mix(in srgb, var(--pistachio) 38%, white)}.guide-figure{max-width:min(620px,100%);margin:20px auto}.guide-figure-scroll{max-width:100%}.guide-figure img{background:var(--card);border:1px solid var(--line);border-radius:12px;width:100%;height:auto;padding:16px 18px;display:block}.guide-figure figcaption{font-family:var(--sans);color:var(--ink-3);text-align:left;justify-content:space-between;align-items:baseline;gap:12px;margin-top:9px;font-size:12.5px;font-style:italic;line-height:1.45;display:flex}.guide-figure figcaption a{color:var(--purple);flex:none;font-size:11px;font-style:normal;font-weight:700;text-decoration:none}.guide-figure figcaption a:hover{text-decoration:underline}@media (max-width:700px){.guide-figure figcaption{flex-direction:column;align-items:flex-start;gap:5px}.course-language-row{justify-content:space-between;align-items:stretch;margin-top:-2px}.course-language-switch{flex:none}.svd-exam-empty{padding:18px 16px}.svd-exam-empty>span{display:none}.section-tabs{overscroll-behavior-x:contain;scrollbar-width:thin;flex-wrap:nowrap;overflow-x:auto}.section-tab{flex:none}.ref-open{opacity:1}.guide,.formula-pane,.code-guide{padding:22px 18px;font-size:16px}.code-guide pre{border-radius:10px;margin-inline:-8px;padding:16px;font-size:12px}.code-sources{padding:17px 15px}.guide-reflection{margin-inline:-4px;padding:17px 15px}.guide-reflection-head,.guide-reflection-rating,.guide-part-actions{flex-direction:column;align-items:stretch}.guide-reflection-rating .difficulty-options,.guide-reflection-head .learning-tooltip,.guide-reflection-head .bookmark-button,.guide-part-ask{width:100%}.guide-toc{margin-left:-8px;margin-right:-8px;top:78px}.guide-figure-scroll{overscroll-behavior-x:contain;-webkit-overflow-scrolling:touch;overflow-x:auto}.guide-figure img{min-width:600px;padding:10px}}.course-page{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--course-page:#f4f2ed;--course-recessed:#ebe8e1;--course-surface:#fbfaf7;--course-ink:#0a0909;--course-muted:#514c56;--course-faint:#716a75;--course-line:#0a09091f;--course-line-strong:#0a09093d;--course-deep:#09090b;--course-deep-2:#1b1820;--course-on-deep:#f7f4ef;--course-shadow:#120e172e;--accent-1:#ff6c96;--accent-1-ink:#a82150;--accent-1-soft:#ffe7ee;--accent-1-side:#ff9ab7;--accent-1-on:#09090b;--accent-2:#4547ea;--accent-2-ink:#3436ba;--accent-2-soft:#e9e9ff;--accent-2-side:#a6a7ff;--accent-3:#ffb31a;--accent-3-ink:#775000;--accent-3-soft:#fff1c9;--accent-3-side:#ffd36a;--course-action:var(--accent-1-ink);--course-on-action:#fff;--paper:var(--course-page);--paper-2:var(--course-recessed);--card:var(--course-surface);--ink:var(--course-ink);--ink-2:var(--course-muted);--ink-3:var(--course-faint);--line:var(--course-line);--line-strong:var(--course-line-strong);--navy:var(--course-ink);--navy-2:color-mix(in srgb, var(--course-ink) 82%, var(--accent-1));--paper-on-navy:var(--course-page);--line-on-navy:#f7f4ef29;--moss:var(--accent-1-ink);--pistachio:var(--accent-1);--green-soft:var(--accent-1-soft);--bronze:var(--accent-2-ink);--bronze-soft:var(--accent-2-soft);--purple:var(--accent-3-ink);--purple-soft:var(--accent-3-soft);--logo-gold:var(--accent-2);background:var(--course-page);min-height:100vh;color:var(--course-ink)}.course-page[data-course=matte1]{--accent-1:#ff6c96;--accent-1-ink:#a82150;--accent-1-soft:#ffe7ee;--accent-1-side:#ff9ab7;--accent-1-on:#09090b;--accent-2:#4547ea;--accent-2-ink:#3436ba;--accent-2-soft:#e9e9ff;--accent-2-side:#a6a7ff;--accent-3:#ffb31a;--accent-3-ink:#775000;--accent-3-soft:#fff1c9;--accent-3-side:#ffd36a}.course-page[data-course=matte2c]{--accent-1:#4547ea;--accent-1-ink:#3436ba;--accent-1-soft:#e9e9ff;--accent-1-side:#a6a7ff;--accent-1-on:#fff;--accent-2:#d8ff70;--accent-2-ink:#4e6500;--accent-2-soft:#f2ffd0;--accent-2-side:#d8ff70;--accent-3:#ff9b63;--accent-3-ink:#98401b;--accent-3-soft:#ffeadf;--accent-3-side:#ffb18d}.course-page[data-course=matte3c]{--accent-1:#8a53ff;--accent-1-ink:#6534c8;--accent-1-soft:#f0e9ff;--accent-1-side:#bea3ff;--accent-1-on:#09090b;--accent-2:#78b8ff;--accent-2-ink:#205e99;--accent-2-soft:#e7f3ff;--accent-2-side:#8dc7ff;--accent-3:#ff8057;--accent-3-ink:#a93f1e;--accent-3-soft:#fff0ea;--accent-3-side:#ffab8d}.course-page[data-course=matte2b]{--accent-1:#ff6c96;--accent-1-ink:#a82150;--accent-1-soft:#ffe7ee;--accent-1-side:#ff9ab7;--accent-1-on:#09090b;--accent-2:#5cdba8;--accent-2-ink:#11694c;--accent-2-soft:#ddf8ed;--accent-2-side:#86e5be;--accent-3:#5d73ff;--accent-3-ink:#3548bd;--accent-3-soft:#e8ebff;--accent-3-side:#aeb9ff}.course-page[data-course=matte4c]{--accent-1:#ff8057;--accent-1-ink:#a93f1e;--accent-1-soft:#fff0ea;--accent-1-side:#ffab8d;--accent-1-on:#09090b;--accent-2:#c9afff;--accent-2-ink:#6949a8;--accent-2-soft:#f1ebff;--accent-2-side:#d4c0ff;--accent-3:#ff6c96;--accent-3-ink:#a82150;--accent-3-soft:#ffe7ee;--accent-3-side:#ff9ab7}.course-page[data-course=tdt4160]{--accent-1:#78b8ff;--accent-1-ink:#205e99;--accent-1-soft:#e7f3ff;--accent-1-side:#8dc7ff;--accent-1-on:#09090b;--accent-2:#5cdba8;--accent-2-ink:#11694c;--accent-2-soft:#ddf8ed;--accent-2-side:#86e5be;--accent-3:#ffe15a;--accent-3-ink:#765900;--accent-3-soft:#fff8cf;--accent-3-side:#ffe57b}.course-page[data-theme=dark]{--lightningcss-light: ;--lightningcss-dark:initial;color-scheme:dark;--course-page:#0e0d10;--course-recessed:#1d1b21;--course-surface:#151419;--course-ink:#f4f2ed;--course-muted:#c6c0ca;--course-faint:#a49da8;--course-line:#f4f2ed21;--course-line-strong:#f4f2ed40;--course-shadow:#00000080;--course-action:var(--accent-1);--course-on-action:var(--accent-1-on);--paper-on-navy:#0e0d10}.course-page[data-course=matte1][data-theme=dark]{--accent-1-ink:#ff9ab7;--accent-1-soft:#29151d;--accent-2-ink:#a6a7ff;--accent-2-soft:#17172d;--accent-3-ink:#ffd36a;--accent-3-soft:#2a2111}.course-page[data-course=matte2c][data-theme=dark]{--accent-1-ink:#a6a7ff;--accent-1-soft:#17172d;--accent-2-ink:#d8ff70;--accent-2-soft:#1d260e;--accent-3-ink:#ffb18d;--accent-3-soft:#2c1911}.course-page[data-course=matte3c][data-theme=dark]{--accent-1-ink:#bea3ff;--accent-1-soft:#21172e;--accent-2-ink:#8dc7ff;--accent-2-soft:#10202f;--accent-3-ink:#ffab8d;--accent-3-soft:#2b1712}.course-page[data-course=matte2b][data-theme=dark]{--accent-1-ink:#ff9ab7;--accent-1-soft:#29151d;--accent-2-ink:#86e5be;--accent-2-soft:#10261e;--accent-3-ink:#aeb9ff;--accent-3-soft:#161a30}.course-page[data-course=matte4c][data-theme=dark]{--accent-1-ink:#ffab8d;--accent-1-soft:#2b1712;--accent-2-ink:#d4c0ff;--accent-2-soft:#211a2f;--accent-3-ink:#ff9ab7;--accent-3-soft:#29151d}.course-page[data-course=tdt4160][data-theme=dark]{--accent-1-ink:#8dc7ff;--accent-1-soft:#10202f;--accent-2-ink:#86e5be;--accent-2-soft:#10261e;--accent-3-ink:#ffe57b;--accent-3-soft:#29240d}.course-page .site-nav{background:color-mix(in srgb, var(--course-deep) 91%, transparent);height:73px;color:var(--course-on-deep);-webkit-backdrop-filter:blur(18px);backdrop-filter:blur(18px);border-bottom-color:#f7f4ef24;padding:10px 28px}.course-page .brand{gap:10px}.course-page .course-brand-mark{border:0;border-radius:9px;width:40px;height:40px}.course-page .course-brand-wordmark{border:0;border-radius:0;width:86px;height:auto}.course-page .site-nav .nav-links{gap:12px}.course-page .site-nav .nav-links a:not(.btn){color:#f7f4efb8}.course-page .site-nav .nav-links a:not(.btn):hover{color:#fff}.course-page .site-nav .nav-personal-link,.course-page .site-nav .panel-toggle{color:#f7f4efc7;background:#f7f4ef0d;border-color:#f7f4ef33}.course-page .site-nav .panel-toggle:hover,.course-page .site-nav .nav-personal-link:hover{color:#fff;border-color:#f7f4ef80}.course-page .site-nav .panel-toggle.on{border-color:var(--accent-1);background:var(--accent-1);color:var(--accent-1-on)}.course-theme-toggle{color:#f7f4ef94;cursor:pointer;background:#f7f4ef0d;border:1px solid #f7f4ef33;border-radius:999px;grid-template-columns:repeat(2,28px);align-items:center;gap:2px;min-width:64px;height:38px;padding:4px;display:grid}.course-theme-icon{width:28px;height:28px;transition:color .22s var(--ease), background .22s var(--ease), transform .22s var(--ease);border-radius:50%;place-items:center;display:grid}.course-theme-icon svg{width:16px;height:16px}.course-page[data-theme=light] .course-theme-sun,.course-page[data-theme=dark] .course-theme-moon{background:var(--accent-1);color:var(--accent-1-on);transform:rotate(0)}.course-theme-toggle:hover{border-color:#f7f4ef7a}.course-theme-toggle:focus-visible{outline:3px solid var(--accent-1-side);outline-offset:3px}.course-page .course-shell,.course-page .problems{background:var(--course-page)}.course-page .units{--ink:var(--course-on-deep);--ink-2:#d7d1db;--ink-3:#aaa2af;--line:#f7f4ef21;--line-strong:#f7f4ef3d;--moss:var(--accent-1-side);--green-soft:color-mix(in srgb, var(--accent-1) 18%, transparent);background:radial-gradient(circle at 112% 18%, transparent 0 72px, color-mix(in srgb, var(--accent-1) 50%, transparent) 73px 75px, transparent 76px 104px, color-mix(in srgb, var(--accent-2) 34%, transparent) 105px 107px, transparent 108px), var(--course-deep);border-right-color:#f7f4ef1f}.course-page .unit:hover{color:#fff;background:#f7f4ef0f}.course-page .unit.active{border-left-color:var(--accent-1-side);background:color-mix(in srgb, var(--accent-1) 18%, transparent);color:#fff}.course-page .unit.active .un,.course-page .unit.active .uc{color:var(--accent-1-side)}.course-page .units-note{color:#aaa2af}.course-page .units-privacy{color:#d7d1db}.course-page .problem,.course-page .guide,.course-page .formula-pane,.course-page .code-guide,.course-page .ref-card,.course-page .tdt-journey,.course-page .tdt-long-answer,.course-page .tdt-performance-lab,.course-page .tdt-flashcards{box-shadow:0 18px 52px -42px var(--course-shadow)}.course-page .problem{border-top:2px solid var(--accent-1)}.course-page .problem:hover{box-shadow:0 22px 58px -40px var(--course-shadow)}.course-page .section-tab.active:after{background:var(--accent-1)}.course-page .eyebrow:before{background:var(--accent-1-ink)}.course-page .ask-btn,.course-page .send,.course-page .chat-fab,.course-page .course-language-switch button.active{border-color:var(--course-action);background:var(--course-action);color:var(--course-on-action)}.course-page .ask-btn:hover,.course-page .send:hover{border-color:color-mix(in srgb, var(--course-action) 82%, var(--course-ink));background:color-mix(in srgb, var(--course-action) 82%, var(--course-ink))}.course-page .panel-toggle.on,.course-page .toggle-btn.open,.course-page .bookmark-button.active{border-color:var(--accent-1-ink);background:var(--accent-1-soft);color:var(--accent-1-ink)}.course-page .solution{border-left:3px solid var(--accent-2);background:color-mix(in srgb, var(--course-page) 88%, var(--accent-2-soft))}.course-page .sol-label,.course-page .sol-fasit-k{color:var(--accent-2-ink)}.course-page .problem-hint{border-color:color-mix(in srgb, var(--accent-3) 32%, var(--course-line));border-left-color:var(--accent-3);background:var(--accent-3-soft)}.course-page .problem-hint-icon,.course-page .problem-hint-title{color:var(--accent-3-ink)}.course-page .guide,.course-page .formula-pane,.course-page .code-guide{color:var(--course-muted)}.course-page .guide em,.course-page .formula-pane em{color:var(--course-faint)}.course-page .markdown-content th{color:var(--course-ink);background:color-mix(in srgb, var(--course-recessed) 76%, var(--course-surface))}.course-page .markdown-content tr:nth-child(2n) td{background:color-mix(in srgb, var(--course-recessed) 48%, var(--course-surface))}.course-page .markdown-content pre{overscroll-behavior-x:contain;max-width:100%;overflow-x:auto}.course-page .code-guide pre,.course-page .tdt-step-detail,.course-page .tdt-performance-equation,.course-page .tdt-performance-results{background:linear-gradient(135deg, var(--course-deep), color-mix(in srgb, var(--course-deep-2) 78%, var(--accent-2)));color:#fff}.course-page .msg.user{background:var(--course-deep);color:var(--course-on-deep)}.course-page .guide-figure img,.course-page .guide-matte4c .guide-figure img{color:#111;filter:none;mix-blend-mode:normal;background:#fff;border-color:#0a090929}.course-page[data-theme=dark] .concept-lab-controls button.active>span,.course-page[data-theme=dark] .mp-step-controls button.active>span,.course-page[data-theme=dark] .tensor-layer-title strong,.course-page[data-theme=dark] .cp-layer-controls button.active>span,.course-page[data-theme=dark] .tucker-stage-controls button.active>span,.course-page[data-theme=dark] .hosvd-step-controls button.active>span,.course-page[data-theme=dark] .tucker-sequence-card.active:before{color:var(--course-page)}.course-page[data-theme=dark] .course-shell-wip{--paper:var(--course-page);--paper-2:var(--course-recessed);--card:var(--course-surface)}.course-page[data-theme=dark] .tdt-source-line,.course-page[data-theme=dark] .tdt-stepper button,.course-page[data-theme=dark] .tdt-answer-field textarea,.course-page[data-theme=dark] .tdt-marking-guide,.course-page[data-theme=dark] .tdt-performance-inputs,.course-page[data-theme=dark] .tdt-performance-inputs input,.course-page[data-theme=dark] .tdt-performance-reset,.course-page[data-theme=dark] .tdt-flashcards__filters,.course-page[data-theme=dark] .tdt-flashcard,.course-page[data-theme=dark] .tdt-flashcards__controls>button,.course-page[data-theme=dark] .tdt-flashcards__grading button{background:var(--course-surface);color:var(--course-ink)}.course-page[data-theme=dark] .tdt-flashcard.is-revealed{background:radial-gradient(circle at 100% 0%, color-mix(in srgb, var(--accent-2) 25%, transparent), transparent 38%), var(--course-surface)}.course-page .tdt-stepper button.active,.course-page .tdt-flashcards__filters button.active,.course-page .tdt-flashcards__controls>.reveal,.course-page .tdt-flashcards__grading .got-it{border-color:var(--course-action);background:var(--course-action);color:var(--course-on-action)}@media (max-width:860px){html{scroll-behavior:auto}.site-nav{background:var(--paper);-webkit-backdrop-filter:none;backdrop-filter:none}.course-page .site-nav{background:var(--course-deep);-webkit-backdrop-filter:none;backdrop-filter:none;padding-inline:18px}.guide-toc{background:var(--card);-webkit-backdrop-filter:none;backdrop-filter:none}.dashboard-course-nav{background:var(--paper);-webkit-backdrop-filter:none;backdrop-filter:none}.guide-part,.guide-section,.guide-interactive-slot,.problem{content-visibility:auto}.guide-part,.guide-section{contain-intrinsic-size:auto 3200px}.guide-matte4c .guide-part,.guide-matte4c .guide-section{contain-intrinsic-size:auto 6400px}.guide-interactive-slot{contain-intrinsic-size:auto 900px}.problem{contain-intrinsic-size:auto 680px}.course-page .units{background:radial-gradient(circle at 105% -55%, transparent 0 82px, color-mix(in srgb, var(--accent-1) 45%, transparent) 83px 85px, transparent 86px), var(--course-deep)}.course-page .unit.active{border-left:none;border-bottom-color:var(--accent-1-side)}}@media (max-width:600px){.course-page .site-nav{padding-inline:14px}.course-page .site-nav .brand{gap:7px}.course-page .course-brand-mark{width:36px;height:36px}.course-page .course-brand-wordmark{width:74px}.course-theme-toggle{grid-template-columns:repeat(2,25px);min-width:58px;height:36px;padding:3px}.course-theme-icon{width:25px;height:25px}}@media (max-width:460px){.course-page .course-brand-wordmark{display:none}}.course-page[data-course=dashboard]{--accent-1:#ff6c96;--accent-1-ink:#a82150;--accent-1-soft:#ffe7ee;--accent-1-side:#ff9ab7;--accent-1-on:#09090b;--accent-2:#4547ea;--accent-2-ink:#3436ba;--accent-2-soft:#e9e9ff;--accent-2-side:#a6a7ff;--accent-3:#ffb31a;--accent-3-ink:#775000;--accent-3-soft:#fff1c9;--accent-3-side:#ffd36a}.course-page[data-course=dashboard][data-theme=dark]{--accent-1-ink:#ff9ab7;--accent-1-soft:#29151d;--accent-2-ink:#a6a7ff;--accent-2-soft:#17172d;--accent-3-ink:#ffd36a;--accent-3-soft:#2a2111}.dashboard-theme{background:radial-gradient(circle at 88% 3%, color-mix(in srgb, var(--accent-1) 11%, transparent), transparent 30rem), var(--course-page);min-height:100vh}.dashboard-theme .dashboard-nav .nav-personal-link[aria-current=page]{border-color:var(--accent-1);background:var(--accent-1);color:var(--accent-1-on)}.dashboard-theme .dashboard-manage-courses,.dashboard-theme .dashboard-open-course,.dashboard-theme .dashboard-add-course-banner button,.dashboard-theme .dashboard-item-filters button.active,.dashboard-theme .dashboard-course-nav a[aria-current=page],.dashboard-theme .checklist-filters button.active,.dashboard-theme .btn-navy{border-color:var(--course-action);background:var(--course-action);color:var(--course-on-action)}.dashboard-theme .dashboard-manage-courses:hover,.dashboard-theme .dashboard-open-course:hover,.dashboard-theme .dashboard-add-course-banner button:hover,.dashboard-theme .btn-navy:hover{border-color:color-mix(in srgb, var(--course-action) 82%, var(--course-ink));background:color-mix(in srgb, var(--course-action) 82%, var(--course-ink));color:var(--course-on-action)}.dashboard-theme .dashboard-manage-courses:focus-visible,.dashboard-theme .dashboard-open-course:focus-visible,.dashboard-theme .dashboard-add-course-banner button:focus-visible,.dashboard-theme .dashboard-item-filters button:focus-visible,.dashboard-theme .dashboard-course-nav a:focus-visible,.dashboard-theme .dashboard-course-nav button:focus-visible,.dashboard-theme .checklist-filters button:focus-visible,.dashboard-theme .btn:focus-visible{outline-color:var(--accent-1-side)}.dashboard-theme .dashboard-course-card,.dashboard-theme .dashboard-kpis article{border-top:2px solid var(--accent-1);box-shadow:0 18px 52px -42px var(--course-shadow)}.dashboard-theme .dashboard-course-card:nth-child(3n+2),.dashboard-theme .dashboard-kpis article:nth-child(3n+2){border-top-color:var(--accent-2)}.dashboard-theme .dashboard-course-card:nth-child(3n),.dashboard-theme .dashboard-kpis article:nth-child(3n){border-top-color:var(--accent-3)}.dashboard-theme .subject-picker-dialog{border-color:var(--course-line-strong);background:var(--course-page);color:var(--course-ink);box-shadow:0 30px 90px #09090b6b}.dashboard-theme .subject-picker-dialog::backdrop{-webkit-backdrop-filter:blur(9px);backdrop-filter:blur(9px);background:#09090bad}.dashboard-theme .subject-picker-topline{background:var(--course-deep);color:#f7f4efb8;border-bottom-color:#f7f4ef24}.dashboard-theme .subject-picker-topline button{color:var(--course-on-deep);background:#f7f4ef0f;border-color:#f7f4ef33}.dashboard-empty-mark{place-items:center;display:grid}.dashboard-empty-mark svg{stroke-linecap:round;stroke-linejoin:round;stroke-width:5px;width:clamp(7rem,18vw,14rem);height:auto}.dashboard-course-card-top span:last-child,.priority-arrow,.checklist-unit-chevron{place-items:center;display:grid}.dashboard-course-card-top span:last-child svg,.dashboard-open-course svg,.priority-arrow svg,.checklist-unit-chevron svg{stroke-linecap:round;stroke-linejoin:round;width:18px;height:18px;display:block}@media (max-width:760px){.dashboard-empty-mark{justify-content:start}}