@import "https://fonts.googleapis.com/css2?family=DM+Mono:wght@300;400;500&family=Manrope:wght@400;500;600;700&family=Playfair+Display:ital,wght@1,600&display=swap";:root{color:#19202b;font-synthesis:none;text-rendering:optimizelegibility;-webkit-font-smoothing:antialiased;--ink:#19202b;--paper:#fffdf8;--paper-deep:#f5f1e8;--coral:#ff655c;--blue:#4e82f7;--gold:#e9ae3f;--violet:#7767d8;--line:#19202b24;--mono:"DM Mono", monospace;background:#f5f1e8;font-family:Manrope,sans-serif}*{box-sizing:border-box}html{scroll-behavior:smooth}body{min-width:320px;min-height:100vh;margin:0}button,a{font:inherit}button{color:inherit}button:focus-visible,a:focus-visible{outline-offset:3px;outline:3px solid #4e82f773}#root{min-height:100vh}@media (prefers-reduced-motion:reduce){*,:before,:after{scroll-behavior:auto!important;transition-duration:.01ms!important;animation-duration:.01ms!important;animation-iteration-count:1!important}}.app-shell{background:var(--paper);min-height:100vh;overflow:hidden}.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}.topbar{border-bottom:1px solid var(--line);z-index:20;-webkit-backdrop-filter:blur(14px);backdrop-filter:blur(14px);background:#fffdf8f0;justify-content:space-between;align-items:center;height:82px;padding:0 clamp(24px,5vw,76px);display:flex;position:relative}.brand{color:var(--ink);align-items:center;gap:12px;text-decoration:none;display:inline-flex}.brand-mark{fill:none;stroke:currentColor;stroke-width:1.7px;width:38px;height:38px}.brand span{line-height:1.1;display:grid}.brand strong{letter-spacing:-.02em;font-size:17px}.brand small{color:#737782;font-family:var(--mono);letter-spacing:.1em;text-transform:uppercase;margin-top:5px;font-size:9px}.top-actions{align-items:center;gap:13px;display:flex}.progress-copy{color:#777b84;font-family:var(--mono);letter-spacing:.04em;margin-right:16px;font-size:11px}.progress-copy b{color:var(--ink)}.icon-button,.menu-button{border:1px solid var(--line);cursor:pointer;background:0 0;height:42px}.icon-button{border-radius:50%;width:42px;font-size:25px;line-height:1;transform:rotate(-20deg)}.menu-button{border-radius:7px;align-items:center;gap:10px;padding:0 13px;font-size:12px;font-weight:700;display:flex}.menu-button kbd{border:1px solid var(--line);font:9px var(--mono);background:#f0ece3;border-radius:3px;padding:3px 5px}.menu-icon{align-content:space-between;width:18px;height:12px;display:grid}.menu-icon i{background:currentColor;height:1.5px;transition:transform .18s;display:block}.menu-icon.is-open i:first-child{transform:translateY(5px)rotate(45deg)}.menu-icon.is-open i:last-child{transform:translateY(-5px)rotate(-45deg)}.chapter-drawer{z-index:40;color:#fff;background:#17202b;flex-direction:column;width:min(440px,92vw);height:100vh;padding:28px;transition:transform .35s cubic-bezier(.22,.9,.32,1);display:flex;position:fixed;top:0;right:0;transform:translate(102%)}.chapter-drawer.is-open{transform:translate(0)}.drawer-heading{font:11px var(--mono);letter-spacing:.1em;text-transform:uppercase;border-bottom:1px solid #ffffff26;justify-content:space-between;align-items:center;padding-bottom:25px;display:flex}.drawer-heading button{color:#fff;cursor:pointer;background:0 0;border:0;font-size:28px}.chapter-drawer ol{flex:1;margin:22px 0;padding:0;list-style:none;overflow-y:auto}.chapter-drawer li+li{border-top:1px solid #ffffff1a}.chapter-drawer li button{color:#fff;text-align:left;cursor:pointer;background:0 0;border:0;grid-template-columns:35px 1fr auto;align-items:center;gap:12px;width:100%;padding:19px 4px;display:grid}.chapter-drawer li button:disabled{opacity:.45;cursor:not-allowed}.chapter-drawer li span,.chapter-drawer li i{font:10px var(--mono);color:#aab1ba;font-style:normal}.chapter-drawer li strong{font-size:15px}.drawer-progress-actions{border-top:1px solid #ffffff26;justify-content:space-between;align-items:center;gap:14px;padding-top:18px;display:flex}.drawer-progress-actions span{color:#959da7;max-width:180px;font:8px/1.5 var(--mono)}.drawer-progress-actions button{color:#fff;cursor:pointer;font:8px var(--mono);text-transform:uppercase;background:0 0;border:1px solid #ffffff40;padding:7px 9px}.drawer-progress-actions button:disabled{opacity:.35;cursor:not-allowed}.drawer-backdrop{z-index:30;cursor:default;background:#0e141b6b;border:0;position:fixed;inset:0}.lesson-search{z-index:42;border:1px solid var(--ink);background:var(--paper);width:min(560px,100vw - 48px);max-height:min(620px,100vh - 90px);box-shadow:9px 10px 0 var(--coral);padding:25px;position:fixed;top:66px;right:clamp(24px,5vw,76px);overflow-y:auto}.lesson-search-heading{justify-content:space-between;align-items:flex-start;gap:20px;display:flex}.lesson-search-heading>div{gap:7px;display:grid}.lesson-search-heading span,.lesson-search>label{color:#777c84;font:8px var(--mono);letter-spacing:.1em;text-transform:uppercase}.lesson-search-heading strong{font-size:19px}.lesson-search-heading button{color:var(--ink);cursor:pointer;background:0 0;border:0;font-size:27px;line-height:1}.lesson-search>label{margin-top:24px;display:block}.lesson-search>input{width:100%;height:44px;color:var(--ink);font:11px var(--mono);background:#fbf8f1;border:1px solid #999b9d;margin-top:7px;padding:0 13px}.lesson-search>input:focus{outline:2px solid var(--blue);outline-offset:2px}.lesson-search ul{margin:18px 0 0;padding:0;list-style:none}.lesson-search li+li{border-top:1px solid var(--line)}.lesson-search li button{width:100%;color:var(--ink);cursor:pointer;text-align:left;background:0 0;border:0;grid-template-columns:28px 1fr auto;align-items:center;gap:12px;padding:14px 4px;display:grid}.lesson-search li button:hover{background:var(--paper-deep)}.lesson-search li button>span:first-child{color:var(--coral);font:9px var(--mono)}.lesson-search li button>span:nth-child(2){gap:5px;display:grid}.lesson-search li strong{font-size:13px}.lesson-search li small{color:#71767f;font-size:9px;line-height:1.4}.lesson-search li i{color:var(--coral);font-size:18px;font-style:normal}.lesson-search>p{color:#6d727b;margin:22px 0 4px;font-size:11px}.search-backdrop{z-index:41;cursor:default;background:#0e141b6b;border:0;position:fixed;inset:0}main{position:relative}.hero-section{background-color:var(--paper);background-image:linear-gradient(#36445609 1px,#0000 1px),linear-gradient(90deg,#36445609 1px,#0000 1px);background-size:34px 34px;grid-template-columns:minmax(0,.92fr) minmax(450px,1.08fr);align-items:center;gap:clamp(40px,7vw,110px);min-height:690px;padding:70px clamp(28px,7vw,112px) 82px;display:grid}.eyebrow{color:#6d737d;font:10px var(--mono);letter-spacing:.16em;align-items:center;gap:10px;margin:0 0 22px;display:flex}.eyebrow span{background:var(--coral);width:22px;height:2px}.hero-copy h1{letter-spacing:-.055em;max-width:650px;margin:0;font-size:clamp(46px,5.3vw,78px);font-weight:600;line-height:.99}.hero-copy h1 em{color:var(--coral);margin-top:11px;font-family:Playfair Display,serif;font-weight:600;display:block}.hero-intro{color:#5c626d;max-width:590px;margin:30px 0 0;font-size:clamp(15px,1.3vw,18px);line-height:1.75}.hero-actions{align-items:center;gap:25px;margin-top:38px;display:flex}.primary-action{background:var(--ink);color:#fff;cursor:pointer;height:54px;box-shadow:6px 6px 0 var(--coral);border:0;border-radius:4px;align-items:center;gap:28px;padding:0 25px;font-size:13px;font-weight:700;transition:transform .16s,box-shadow .16s;display:flex}.primary-action:hover{box-shadow:3px 3px 0 var(--coral);transform:translate(3px,3px)}.resume-note{color:#7c8088;font:10px/1.7 var(--mono);display:grid}.resume-note b{color:var(--ink);text-transform:uppercase;letter-spacing:.12em}.hero-illustration{isolation:isolate;place-items:center;min-height:490px;display:grid;position:relative}.grid-paper{z-index:-3;border:1px solid var(--line);background:#f4eee3;position:absolute;inset:3% 3% 0 0;transform:rotate(2deg);box-shadow:16px 17px #19202b0f}.grid-paper:before{content:"";opacity:.45;background-image:linear-gradient(#9aa3ae33 1px,#0000 1px),linear-gradient(90deg,#9aa3ae33 1px,#0000 1px);background-size:24px 24px;position:absolute;inset:0}.orbit{z-index:-2;border:1px dashed #19202b3d;border-radius:50%;position:absolute}.orbit-one{width:400px;height:400px;animation:35s linear infinite spin}.orbit-two{border-color:#ff655c80;width:305px;height:305px;animation:24s linear infinite reverse spin}.orbit:before{content:"";background:var(--coral);border-radius:50%;width:11px;height:11px;position:absolute;top:-6px;left:50%}.array-stage{background:var(--paper);width:min(440px,86%);min-height:285px;box-shadow:9px 10px 0 var(--ink);border:1px solid #19202b52;padding:25px 28px 21px;transform:rotate(-1.4deg)}.array-label{font:9px var(--mono);color:#777c85;text-transform:uppercase;letter-spacing:.14em}.array-bars{align-items:flex-end;gap:9px;height:185px;margin-top:15px;display:flex}.array-bar{height:var(--bar-height);border:1px solid var(--ink);background:#f7c95f;flex:1;place-items:start center;min-height:45px;padding-top:10px;animation:5.5s ease-in-out infinite bars;display:grid;box-shadow:3px 0 #19202b1f}.array-bar:nth-child(2n){background:var(--coral);color:#fff;animation-delay:-2.3s}.array-bar span{font:11px var(--mono)}.stage-caption{font:9px var(--mono);color:#6e737b;align-items:center;gap:8px;margin-top:16px;display:flex}.pulse-dot{background:#54a378;border-radius:50%;width:7px;height:7px;animation:1.7s ease-out infinite pulse;box-shadow:0 0 0 5px #54a3781f}.float-symbol{font-family:var(--mono);z-index:2;position:absolute}.symbol-one{color:var(--blue);font-size:28px;top:11%;left:-1%;transform:rotate(-12deg)}.symbol-two{background:var(--blue);color:#fff;padding:10px 14px;bottom:5%;right:0;transform:rotate(7deg)}.symbol-three{color:var(--coral);font-size:34px;top:4%;right:10%;transform:rotate(28deg)}.learning-path{background:var(--paper-deep);border-top:1px solid var(--line);padding:96px clamp(28px,7vw,112px) 110px}.section-heading{grid-template-columns:1.2fr .8fr;align-items:end;gap:80px;margin-bottom:48px;display:grid}.section-heading h2{letter-spacing:-.045em;max-width:680px;margin:0;font-size:clamp(33px,4vw,54px);line-height:1.08}.section-heading>p{color:#686e77;max-width:430px;margin:0 0 5px;font-size:14px;line-height:1.8}.chapter-grid{grid-template-columns:repeat(6,1fr);gap:17px;display:grid}.chapter-card{border:1px solid var(--line);border-top:4px solid var(--tone);background:var(--paper);flex-direction:column;grid-column:span 2;min-height:330px;padding:23px;transition:transform .18s,box-shadow .18s;display:flex}.chapter-card:hover{transform:translateY(-5px);box-shadow:0 15px 30px #21262e14}.chapter-card:nth-child(4),.chapter-card:nth-child(5){grid-column:span 3}.tone-coral{--tone:var(--coral)}.tone-blue{--tone:var(--blue)}.tone-gold{--tone:var(--gold)}.tone-violet{--tone:var(--violet)}.chapter-card-top{justify-content:space-between;align-items:start;min-height:24px;display:flex}.chapter-number{color:#737982;font:9px var(--mono);letter-spacing:.12em}.status-pill{border:1px solid color-mix(in srgb, var(--tone), transparent 45%);color:var(--tone);font:8px var(--mono);text-transform:uppercase;letter-spacing:.08em;padding:4px 7px}.status-pill.is-complete{color:#4b946c;border-color:#65aa84}.lock-mark{color:#858a92}.chapter-card h3{letter-spacing:-.035em;margin:30px 0 10px;font-size:22px}.chapter-card p{color:#6d727b;margin:0;font-size:12px;line-height:1.7}.chapter-meta{color:#7b7f87;font:9px var(--mono);justify-content:space-between;margin-top:auto;padding-top:25px;display:flex}.progress-track{background:#e7e3da;height:3px;margin:10px 0 18px}.progress-track span{background:var(--tone);height:100%;display:block}.card-link{cursor:pointer;text-align:left;background:0 0;border:0;justify-content:space-between;padding:0;font-size:11px;font-weight:700;display:flex}.card-link:disabled{color:#a3a4a6;cursor:not-allowed}.card-link span{color:var(--tone);font-size:18px}.principles{background:var(--paper-deep);grid-template-columns:repeat(3,1fr);padding:0 clamp(28px,7vw,112px) 110px;display:grid}.principles div{border:1px solid var(--line);background:#fffdf885;border-right:0;padding:28px 36px}.principles div:last-child{border-right:1px solid var(--line)}.principles span{color:var(--coral);font:10px var(--mono);margin-bottom:27px;display:block}.principles strong{font-size:15px}.principles p{color:#747983;margin:8px 0 0;font-size:11px;line-height:1.7}footer{color:#f7f1e8;background:#17202b;grid-template-columns:1fr 1fr 1fr;align-items:center;min-height:145px;padding:0 clamp(28px,7vw,112px);display:grid}.footer-brand{color:inherit}.footer-brand .brand-mark{width:30px}footer p{text-align:center;font-family:Playfair Display,serif;font-style:italic}footer>span{text-align:right;color:#9da4ae;font:9px var(--mono);text-transform:uppercase;letter-spacing:.08em}.catalogue-page{background-color:var(--paper-deep);background-image:linear-gradient(#36445608 1px,#0000 1px),linear-gradient(90deg,#36445608 1px,#0000 1px);background-size:32px 32px;min-height:calc(100vh - 82px);padding:32px clamp(24px,5vw,76px) 100px}.catalogue-heading{grid-template-columns:minmax(0,1fr) 190px;align-items:center;gap:60px;min-height:290px;display:grid}.catalogue-heading .eyebrow{margin-bottom:16px}.catalogue-heading h1{letter-spacing:-.065em;margin:0;font-size:clamp(50px,7vw,88px);line-height:.95}.catalogue-heading>div>p:last-child{color:#686e77;max-width:650px;margin:22px 0 0;font-size:14px;line-height:1.7}.catalogue-progress{border:1px solid var(--ink);background:var(--paper);box-shadow:6px 6px 0 var(--coral);grid-template-columns:1fr auto;align-items:end;padding:23px;display:grid;transform:rotate(2deg)}.catalogue-progress>span{color:#737982;font:9px var(--mono)}.catalogue-progress>strong{font:27px var(--mono)}.catalogue-progress>i{background:#e4dfd5;grid-column:1/-1;height:4px;margin-top:14px;overflow:hidden}.catalogue-progress>i b{background:var(--coral);height:100%;display:block}.lesson-catalogue-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;display:grid}.lesson-catalogue-card{border:1px solid var(--line);border-top:4px solid var(--coral);background:var(--paper);flex-direction:column;min-height:400px;padding:23px;transition:transform .18s,box-shadow .18s;display:flex;box-shadow:5px 6px #19202b14}.lesson-catalogue-card:last-child:nth-child(odd){grid-column:1/-1;min-height:340px}.lesson-catalogue-card:hover{transform:translateY(-5px);box-shadow:8px 10px #19202b1f}.lesson-catalogue-card.is-complete{border-top-color:#65aa84}.catalogue-card-top{color:#777c84;min-height:25px;font:8px var(--mono);letter-spacing:.08em;justify-content:space-between;display:flex}.catalogue-card-top i{color:#4b946c;font-style:normal}.lesson-catalogue-card h2{letter-spacing:-.05em;margin:38px 0 13px;font-size:clamp(27px,2.6vw,38px)}.lesson-catalogue-card p{color:#6a7079;margin:0;font-size:11px;line-height:1.75}.lesson-catalogue-card dl{grid-template-columns:repeat(3,1fr);margin:auto 0 24px;padding-top:30px;display:grid}.lesson-catalogue-card dl div{border-left:1px solid var(--line);padding:0 12px}.lesson-catalogue-card dl div:first-child{border-left:0;padding-left:0}.lesson-catalogue-card dt{color:#878b92;font:7px var(--mono);letter-spacing:.1em}.lesson-catalogue-card dd{font:11px var(--mono);margin:6px 0 0}.lesson-catalogue-card>button{border:1px solid var(--ink);background:var(--ink);color:#fff;cursor:pointer;justify-content:space-between;align-items:center;min-height:44px;padding:0 13px;font-size:9px;font-weight:700;display:flex}.lesson-catalogue-card>button span{color:var(--coral);font-size:17px}.catalogue-note{border:1px solid var(--line);background:#fffdf8ad;grid-template-columns:150px minmax(0,760px);gap:30px;margin-top:18px;padding:25px 29px;display:grid}.catalogue-note span{color:var(--coral);font:8px var(--mono);letter-spacing:.12em}.catalogue-note p{color:#646a73;margin:0;font-size:11px;line-height:1.75}.problem-brief{border:1px solid var(--ink);border-top:4px solid var(--coral);background:var(--paper);grid-template-columns:145px minmax(240px,1.2fr) minmax(220px,.8fr);margin:0 0 32px;display:grid;box-shadow:7px 8px #19202b1a}.problem-brief-label{border-right:1px solid var(--line);background:var(--ink);color:#fff;flex-direction:column;justify-content:space-between;padding:22px 18px;display:flex}.problem-brief-label span,.problem-brief-constraints>strong,.problem-brief-question span{font:8px var(--mono);letter-spacing:.11em}.problem-brief-label span{color:var(--coral)}.problem-brief-label i{color:#adb3bb;font:8px/1.5 var(--mono);font-style:normal}.problem-brief-story{border-right:1px solid var(--line);padding:24px 26px}.problem-brief-story h2{letter-spacing:-.03em;margin:0 0 12px;font-size:20px}.problem-brief-story p,.problem-brief-question p{color:#646a73;margin:0;font-size:10px;line-height:1.7}.problem-brief-constraints{padding:22px}.problem-brief-constraints>strong{color:#747983}.problem-brief-constraints ul{gap:8px;margin:12px 0 0;padding:0;list-style:none;display:grid}.problem-brief-constraints li{color:#626872;padding-left:13px;font-size:9px;line-height:1.45;position:relative}.problem-brief-constraints li:before{content:"×";color:var(--coral);font:9px var(--mono);position:absolute;left:0}.problem-brief-question{border-top:1px solid var(--line);background:#f5f0e7;grid-column:2/-1;grid-template-columns:155px 1fr;align-items:center;gap:18px;padding:17px 24px;display:grid}.problem-brief-question span{color:var(--coral)}.problem-brief-question p{color:var(--ink);font-weight:700}.growth-workspace{background:var(--paper);box-shadow:11px 12px 0 var(--ink);border:1px solid #19202b42;grid-template-columns:minmax(0,1.45fr) minmax(320px,.75fr);display:grid}.growth-panel{border-right:1px solid var(--line);min-width:0}.input-size-experiment{border-bottom:1px solid var(--line);background:#f6f2e9;grid-template-columns:minmax(175px,.8fr) 32px minmax(130px,1fr) 32px 58px;align-items:center;gap:9px;min-height:68px;padding:11px 18px;display:grid}.input-size-experiment>div{gap:4px;display:grid}.input-size-experiment label{color:var(--ink);font-size:9px;font-weight:700}.input-size-experiment>div span{color:#747983;font:7px/1.4 var(--mono)}.input-size-experiment button{border:1px solid var(--ink);background:var(--paper);width:32px;height:32px;color:var(--ink);cursor:pointer;font:15px var(--mono);border-radius:50%}.input-size-experiment button:disabled{opacity:.3;cursor:not-allowed}.input-size-experiment input{width:100%;accent-color:var(--coral);cursor:grab}.input-size-experiment input:active{cursor:grabbing}.input-size-experiment input:focus-visible{outline:2px solid var(--blue);outline-offset:4px}.input-size-experiment output{min-width:58px;color:var(--coral);font:17px var(--mono);justify-content:center;align-items:baseline;gap:4px;display:flex}.input-size-experiment output span{color:#747983;font-size:7px}.growth-bars{background-image:linear-gradient(#3644560d 1px,#0000 1px),linear-gradient(90deg,#3644560d 1px,#0000 1px);background-size:23px 23px;align-content:center;gap:30px;min-height:390px;padding:43px 34px;display:grid}.growth-row{grid-template-columns:112px minmax(0,1fr) 42px;align-items:center;gap:14px;display:grid}.growth-row>div:first-child{gap:5px;display:grid}.growth-row strong{font-size:10px}.growth-row code{color:#737982;font:9px var(--mono);background:0 0}.growth-row>b{font:12px var(--mono);text-align:right}.growth-track{border:1px solid var(--ink);background:#fffdf8bf;height:29px;padding:3px}.growth-track span{border:1px solid var(--ink);background:var(--rate-color);min-width:5px;height:100%;transition:width .35s cubic-bezier(.22,.9,.32,1);display:block}.rate-constant{--rate-color:#65aa84}.rate-logarithmic{--rate-color:var(--blue)}.rate-linear{--rate-color:var(--gold)}.rate-quadratic{--rate-color:var(--coral)}.growth-guide{color:#fff;background:#18212c;min-width:0}.growth-guide .panel-label{color:#a9afb7;border-color:#ffffff24}.growth-guide ol{margin:14px 0 0;padding:0 22px;list-style:none}.growth-guide li{border-bottom:1px solid #ffffff1a;grid-template-columns:70px 1fr;align-items:center;gap:8px;min-height:72px;display:grid}.growth-guide li code{color:var(--coral);font:12px var(--mono);background:0 0}.growth-guide li strong{font-size:11px}.growth-guide li p{color:#aeb5be;margin:5px 0 0;font-size:9px;line-height:1.45}.operation-stage{background-image:linear-gradient(#3644560d 1px,#0000 1px),linear-gradient(90deg,#3644560d 1px,#0000 1px);background-size:23px 23px;align-content:center;gap:48px;min-height:390px;padding:58px 38px;display:grid}.operation-total{gap:20px;display:grid}.operation-total>div:first-child{grid-template-columns:1fr auto;align-items:end;gap:4px 20px;display:grid}.operation-total>div:first-child span{color:#747983;font:8px var(--mono);letter-spacing:.1em;text-transform:uppercase}.operation-total>div:first-child strong{font:42px var(--mono);grid-row:span 2}.operation-total>div:first-child code{color:var(--ink);font:11px var(--mono);background:0 0}.operation-stack{border:1px solid var(--ink);background:var(--paper);min-height:72px;display:flex;box-shadow:5px 5px #19202b1f}.operation-stack span{border-right:1px solid var(--ink);min-width:42px;color:var(--ink);font:7px var(--mono);text-align:center;place-items:center;padding:8px 5px;transition:flex .35s cubic-bezier(.22,.9,.32,1);display:grid}.operation-stack span:last-child{border-right:0}.segment-setup{background:#65aa84}.segment-first{background:var(--gold)}.segment-second{background:var(--coral);color:#fff!important}.operation-conclusion{justify-content:center;align-items:center;gap:clamp(7px,1.4vw,17px);display:flex}.operation-conclusion span,.operation-conclusion strong,.operation-conclusion em{border:1px solid var(--ink);background:var(--paper);font:11px var(--mono);padding:9px 11px;font-style:normal}.operation-conclusion i,.operation-conclusion b{font:12px var(--mono);font-style:normal}.operation-conclusion em{border-color:var(--coral);background:var(--coral);color:#fff}.operation-code ol{margin-top:28px}.operation-code li{min-height:90px}.memory-stage{background-image:linear-gradient(#3644560d 1px,#0000 1px),linear-gradient(90deg,#3644560d 1px,#0000 1px);background-size:23px 23px;align-content:center;gap:17px;min-height:390px;padding:36px 34px;display:grid}.memory-row{grid-template-columns:105px minmax(0,1fr) 30px;align-items:center;gap:13px;display:grid}.memory-row>div:first-child{gap:5px;display:grid}.memory-row strong{font-size:10px}.memory-row code{color:#747983;font:7px var(--mono);text-transform:uppercase;background:0 0}.memory-row>b{font:11px var(--mono);text-align:right}.memory-cells{align-items:stretch;gap:4px;min-height:44px;display:flex}.memory-cells i{border:1px solid var(--ink);background:var(--cell-color);min-width:20px;color:var(--cell-text,var(--ink));font:7px var(--mono);flex:0 46px;place-items:center;font-style:normal;animation:.28s ease-out both memory-cell-in;display:grid}.memory-cells i:nth-child(2){animation-delay:25ms}.memory-cells i:nth-child(3){animation-delay:50ms}.memory-cells i:nth-child(4){animation-delay:75ms}.memory-cells i:nth-child(5){animation-delay:.1s}.memory-cells i:nth-child(6){animation-delay:.125s}.memory-cells i:nth-child(7){animation-delay:.15s}.memory-cells i:nth-child(8){animation-delay:.175s}.memory-cells.tone-input{--cell-color:#e7e2d8}.memory-cells.tone-constant{--cell-color:#65aa84;--cell-text:white}.memory-cells.tone-linear{--cell-color:var(--coral);--cell-text:white}.memory-divider{color:#747983;font:7px var(--mono);letter-spacing:.1em;align-items:center;gap:12px;display:flex}.memory-divider:before,.memory-divider:after{content:"";background:var(--line);flex:1;height:1px}.input-memory{opacity:.72}.space-guide li{min-height:90px}.case-best{--rate-color:#65aa84}.case-average{--rate-color:var(--gold)}.case-worst{--rate-color:var(--coral)}.case-guide li{min-height:90px}.recursion-stage{background-image:linear-gradient(#3644560d 1px,#0000 1px),linear-gradient(90deg,#3644560d 1px,#0000 1px);background-size:23px 23px;grid-template-columns:minmax(130px,.45fr) minmax(220px,1fr);align-items:center;gap:30px;min-height:410px;padding:30px 34px;display:grid}.folder-depth{gap:6px;display:grid}.folder-depth span{color:#8a8e94;min-height:29px;font:8px var(--mono);background:#fffdf8a6;border:1px dashed #9da0a3;align-items:center;padding:0 10px;transition:transform .22s,background .22s,color .22s;display:flex}.folder-depth span.is-visited{border-style:solid;border-color:var(--blue);background:var(--blue);color:#fff;transform:translate(6px)}.call-stack{gap:7px;display:grid}.call-stack>strong,.call-stack>em{color:#747983;font:7px var(--mono);letter-spacing:.1em;text-align:center;font-style:normal}.call-stack>div{border:2px solid var(--ink);background:#fffdf8d1;border-top:0;flex-direction:column;justify-content:flex-start;gap:5px;min-height:265px;padding:8px;display:flex;box-shadow:5px 5px #19202b1f}.call-stack>div>span{border:1px solid var(--ink);background:#e6e1d7;gap:3px;min-height:42px;padding:7px 10px;animation:.26s ease-out both memory-cell-in;display:grid}.call-stack>div>span b{font:8px var(--mono)}.call-stack>div>span small{color:#71767e;font-size:7px}.call-stack>div>span.is-active{background:var(--gold);border-width:2px;transform:translate(5px)}.call-stack>div>span.phase-base{color:#fff;background:#65aa84}.call-stack>div>span.phase-base small{color:#fff}.call-stack>div>span.phase-unwind{background:var(--coral);color:#fff}.call-stack>div>span.phase-unwind small{color:#fff}.call-stack>div>i{color:#8a8e94;font:9px var(--mono);margin:auto;font-style:normal}.recursion-guide li{min-height:90px}.tradeoff-stage{background-image:linear-gradient(#3644560d 1px,#0000 1px),linear-gradient(90deg,#3644560d 1px,#0000 1px);background-size:23px 23px;grid-template-columns:1fr 34px 1fr;align-items:center;gap:14px;min-height:410px;padding:45px 34px;display:grid}.tradeoff-stage>b{font:9px var(--mono);text-align:center}.tradeoff-stage article{border:1px solid var(--ink);background:var(--paper);opacity:.66;flex-direction:column;min-height:230px;padding:22px;transition:transform .22s,box-shadow .22s,opacity .22s;display:flex}.tradeoff-stage article.is-recommended{opacity:1;box-shadow:7px 8px 0 var(--coral);transform:translateY(-7px)}.tradeoff-stage article>span{color:var(--coral);font:7px var(--mono);letter-spacing:.1em}.tradeoff-stage h3{margin:12px 0 25px;font-size:16px}.tradeoff-stage article>strong{font:38px var(--mono)}.tradeoff-stage article>strong small{color:#747983;font:7px var(--mono);display:block}.tradeoff-stage article>p{color:#646a73;font:8px var(--mono);margin:auto 0 0}.not-found-page{background-color:var(--paper-deep);background-image:linear-gradient(#36445609 1px,#0000 1px),linear-gradient(90deg,#36445609 1px,#0000 1px);background-size:32px 32px;flex-direction:column;justify-content:center;align-items:flex-start;min-height:calc(100vh - 227px);padding:100px clamp(24px,9vw,145px);display:flex}.not-found-code{color:var(--coral);font:12px var(--mono);letter-spacing:.18em}.not-found-page h1{letter-spacing:-.06em;max-width:800px;margin:17px 0;font-size:clamp(47px,7vw,88px);line-height:.98}.not-found-page>p:not(.eyebrow){color:#686e77;font-size:14px}.not-found-page code{color:var(--ink);font:11px var(--mono);background:#ebe5da;padding:3px 6px}.not-found-page>div{align-items:center;gap:25px;margin-top:30px;display:flex}.not-found-home{border:0;border-bottom:1px solid var(--ink);cursor:pointer;background:0 0;padding:10px 0;font-size:10px;font-weight:700}.lesson-page{background-color:var(--paper-deep);background-image:linear-gradient(#36445608 1px,#0000 1px),linear-gradient(90deg,#36445608 1px,#0000 1px);background-size:32px 32px;min-height:calc(100vh - 82px);padding:32px clamp(24px,5vw,76px) 100px}.lesson-crumbs{color:#858990;font:9px var(--mono);text-transform:uppercase;letter-spacing:.08em;align-items:center;gap:12px;display:flex}.lesson-crumbs button{color:var(--ink);cursor:pointer;background:0 0;border:0;padding:0}.lesson-crumbs strong{color:var(--coral);font-weight:500}.lesson-switcher{justify-content:flex-end;gap:7px;margin-top:-24px;display:flex}.lesson-switcher button{border:1px solid var(--line);color:#737982;cursor:pointer;font:8px var(--mono);letter-spacing:.04em;background:#fffdf8a6;align-items:center;gap:7px;padding:8px 11px;transition:border-color .16s,background .16s,color .16s;display:inline-flex}.lesson-switcher button:hover{border-color:var(--ink);color:var(--ink)}.lesson-switcher button.is-current{border-color:var(--ink);background:var(--ink);color:#fff}.lesson-check{color:#fff;background:#65aa84;border-radius:50%;place-items:center;width:15px;height:15px;font-size:9px;display:inline-grid}.lesson-switcher button.is-current .lesson-check{color:#3f835e;background:#fff}.lesson-heading{justify-content:space-between;align-items:center;gap:40px;min-height:238px;display:flex}.lesson-heading .eyebrow{margin-bottom:15px}.lesson-heading h1{letter-spacing:-.06em;margin:0;font-size:clamp(48px,6vw,78px);line-height:1}.lesson-heading>div>p:last-child{color:#686e77;margin:17px 0 0;font-size:14px}.complexity-stamp{border:1px solid var(--ink);background:var(--paper);width:132px;height:132px;box-shadow:5px 5px 0 var(--coral);border-radius:50%;flex:none;place-content:center;justify-items:center;display:grid;transform:rotate(5deg)}.complexity-stamp small,.complexity-stamp span{font:8px var(--mono);letter-spacing:.12em}.complexity-stamp strong{font:25px var(--mono);margin:3px 0}.complexity-stamp strong.is-long{white-space:nowrap;font-size:17px}.complexity-stamp span{color:#777c84}.lesson-workspace{background:var(--paper);box-shadow:11px 12px 0 var(--ink);border:1px solid #19202b42;grid-template-columns:minmax(0,1.45fr) minmax(330px,.75fr);display:grid}.visualizer-panel{border-right:1px solid var(--line);min-width:0}.panel-label{border-bottom:1px solid var(--line);color:#727781;height:48px;font:9px var(--mono);letter-spacing:.1em;justify-content:space-between;align-items:center;padding:0 18px;display:flex}.panel-label button{border:1px solid var(--line);color:var(--ink);cursor:pointer;font:8px var(--mono);text-transform:uppercase;background:0 0;border-radius:3px;padding:5px 8px}.panel-label i{letter-spacing:0;text-transform:none;font-style:normal}.panel-actions{gap:6px;display:flex}.panel-actions button[aria-expanded=true]{border-color:var(--ink);background:var(--ink);color:#fff}.array-input-panel{border-bottom:1px solid var(--line);background:#f6f2e9;grid-template-columns:minmax(170px,.6fr) minmax(280px,1fr);align-items:center;column-gap:18px;padding:15px 18px;display:grid}.array-input-copy{gap:4px;display:grid}.array-input-copy label{color:var(--ink);font-size:10px;font-weight:700}.array-input-copy span{color:#747983;font:8px/1.5 var(--mono)}.array-input-field{grid-template-columns:minmax(0,1fr) auto auto;gap:6px;display:grid}.array-input-field input{background:var(--paper);min-width:0;height:34px;color:var(--ink);font:10px var(--mono);border:1px solid #a8a8a2;border-radius:3px;padding:0 10px}.array-input-field input:focus{outline:2px solid var(--blue);outline-offset:1px}.array-input-field input[aria-invalid=true]{border-color:var(--coral)}.array-input-field button{border:1px solid var(--ink);background:var(--ink);color:#fff;cursor:pointer;height:34px;font:8px var(--mono);text-transform:uppercase;border-radius:3px;padding:0 10px}.array-input-field button:last-child{border-color:var(--line);color:var(--ink);background:0 0}.array-input-error{color:#b43e36;font:8px/1.5 var(--mono);grid-column:2;margin:7px 0 0}.search-input-panel{border-bottom:1px solid var(--line);background:#f6f2e9;grid-template-columns:minmax(180px,.85fr) minmax(190px,1.15fr) 92px auto;align-items:end;gap:12px;padding:15px 18px;display:grid}.search-input-copy{align-self:center;gap:4px;display:grid}.search-input-copy strong{font-size:10px}.search-input-copy span{color:#747983;font:8px/1.5 var(--mono)}.search-input-panel label{color:#747983;font:8px var(--mono);text-transform:uppercase;letter-spacing:.06em;gap:5px;display:grid}.search-input-panel input{background:var(--paper);width:100%;min-width:0;height:34px;color:var(--ink);font:10px var(--mono);border:1px solid #a8a8a2;border-radius:3px;padding:0 9px}.search-input-panel input:focus{outline:2px solid var(--blue);outline-offset:1px}.search-input-panel input[aria-invalid=true]{border-color:var(--coral)}.search-input-actions{gap:5px;display:flex}.search-input-actions button{border:1px solid var(--ink);background:var(--ink);color:#fff;cursor:pointer;height:34px;font:8px var(--mono);text-transform:uppercase;border-radius:3px;padding:0 9px}.search-input-actions button:last-child{border-color:var(--line);color:var(--ink);background:0 0}.search-input-panel .array-input-error{grid-column:2/-1;margin:0}.linked-experiment{border-bottom:1px solid var(--line);background:#f6f2e9;grid-template-columns:minmax(155px,1fr) 125px 110px 65px;align-items:end;gap:10px;min-height:76px;padding:12px 18px;display:grid}.linked-experiment>div{align-self:center;gap:4px;display:grid}.linked-experiment>div strong{font-size:9px}.linked-experiment>div span{color:#747983;font:7px var(--mono)}.linked-experiment label{color:#747983;font:7px var(--mono);text-transform:uppercase;gap:5px;display:grid}.linked-experiment select,.linked-experiment input{background:var(--paper);width:100%;height:33px;color:var(--ink);font:9px var(--mono);border:1px solid #999;padding:0 8px}.linked-experiment>button{border:1px solid var(--ink);background:var(--ink);color:#fff;cursor:pointer;height:33px;font:8px var(--mono);text-transform:uppercase}.linked-experiment>p{color:#b43e36;font:8px var(--mono);grid-column:2/-1;margin:0}.linked-delete-experiment{grid-template-columns:minmax(180px,1fr) 150px 70px}.linked-experiment>button.secondary-experiment{border-color:var(--line);color:var(--ink);background:0 0}.linked-search-experiment{grid-template-columns:minmax(170px,1fr) 115px 85px 65px}.stack-experiment{grid-template-columns:minmax(155px,1fr) 90px 105px 88px 65px}.queue-experiment{grid-template-columns:minmax(155px,1fr) 95px 105px 88px 65px}.linked-cycle-experiment{grid-template-columns:minmax(180px,1fr) 145px 95px 65px}.traversal-registers{border-bottom:1px solid var(--line);background:#fffdf8;grid-template-columns:repeat(3,minmax(0,1fr));gap:9px;min-height:58px;padding:9px 18px;display:grid}.traversal-registers>span{border:1px solid #d5d0c5;justify-content:space-between;align-items:center;gap:8px;padding:7px 10px;display:flex}.traversal-registers small{color:#747983;font:7px var(--mono)}.traversal-registers strong{color:var(--blue);font:11px var(--mono)}.traversal-registers .is-null strong{color:var(--coral)}.linked-pointer-registers .is-released{opacity:.7;border-style:dashed}.linked-pointer-registers .is-released strong{color:#747983;text-transform:uppercase;font-size:8px}.linked-stage{background-image:linear-gradient(#3644560d 1px,#0000 1px),linear-gradient(90deg,#3644560d 1px,#0000 1px);background-size:23px 23px;min-height:390px;padding:78px 25px 30px;position:relative;overflow-x:auto}.linked-head{color:var(--coral);font:8px var(--mono);position:absolute;top:36px;left:28px}.linked-state-legend{color:#6f747c;font:6px var(--mono);text-transform:uppercase;gap:13px;display:flex;position:absolute;top:19px;right:24px}.linked-state-legend span{white-space:nowrap;align-items:center;gap:5px;display:flex}.linked-state-legend i{border:1px solid var(--ink);width:9px;height:9px;display:inline-block}.linked-state-legend .legend-current{background:var(--coral);border:0;border-radius:50%}.linked-state-legend .legend-visited{background:repeating-linear-gradient(135deg,#ddd8ce 0 2px,#0000 2px 4px);border-color:#8a8f96}.linked-state-legend .legend-unseen{background:var(--paper)}.linked-chain{align-items:center;gap:8px;min-width:max-content;display:flex}.linked-node-group{align-items:center;gap:8px;display:flex}.linked-chain>b,.linked-node-group>b{color:var(--blue);font:19px var(--mono)}.linked-pointer{transform-origin:0;transition:color .18s,text-shadow .18s;display:inline-block}.linked-pointer.is-active{color:var(--coral);text-shadow:0 0 9px #ff655c6b;animation:.7s ease-in-out infinite alternate pointer-pulse}.linked-pointer.is-null{white-space:nowrap}.linked-null-target{align-items:center;min-height:112px;display:inline-flex;position:relative}.linked-cycle-target{border:1px dashed var(--coral);min-width:88px;color:var(--coral);font:7px/1.4 var(--mono);text-align:center;border-radius:50%;padding:8px}.linked-variable-pointer{z-index:3;color:var(--coral);font:8px var(--mono);text-transform:lowercase;justify-items:center;display:grid;position:absolute;top:-48px;left:50%}.linked-variable-pointer b{background:var(--paper);font:inherit;border:1px solid;border-radius:999px;padding:5px 8px;box-shadow:2px 2px #19202b24}.linked-variable-pointer i{font:14px var(--mono);margin-top:2px}.linked-variable-pointer.is-found{color:#28785f}.linked-variable-pointer.is-found b{background:#e5f3e9}.linked-variable-pointer.is-reference{color:var(--blue)}.linked-variable-pointer.is-new{color:#28785f}.linked-variable-pointer.is-danger{color:#b43e36}.linked-stage article{border:1px solid var(--ink);background:var(--paper);grid-template-columns:1fr auto;align-content:center;gap:8px;width:105px;min-height:112px;padding:12px;transition:transform .22s,background .22s,opacity .22s;display:grid;position:relative;box-shadow:4px 5px #19202b21}.linked-stage article>span{font:24px var(--mono);grid-column:1/-1}.linked-stage article small{color:#747983;font:6px var(--mono)}.linked-stage article code{color:var(--ink);font:6px var(--mono);background:0 0}.linked-stage article.is-active{background:var(--gold);border-width:2px}.linked-stage article.is-new{border-style:dashed;border-color:var(--coral)}.linked-stage article.is-visited{opacity:.72;background:repeating-linear-gradient(135deg,#f0ece3 0 6px,#e8e3da 6px 8px);border-color:#8a8f96}.linked-stage article.is-found{opacity:1;background:#e5f3e9;border:2px solid #28785f;box-shadow:4px 5px #28785f33}.linked-stage article.is-edge-source code{background:var(--coral);color:#fff;padding:3px;animation:.7s ease-in-out infinite alternate pointer-pulse}.linked-node-state{color:#686d74;font:5px var(--mono);letter-spacing:.04em;font-style:normal;position:absolute;top:6px;right:7px}.linked-node-state.is-found{color:#28785f;font-weight:700}.linked-edge-operation{border:1px solid var(--coral);background:var(--paper);align-items:center;gap:8px;width:max-content;margin:24px auto 0;padding:7px 11px;display:flex;box-shadow:3px 3px #19202b1f}.linked-edge-operation small{color:#747983;font:6px var(--mono)}.linked-edge-operation code{color:var(--blue);font:9px var(--mono);background:0 0;padding:0}.linked-edge-operation b{color:var(--coral);font:12px var(--mono)}.linked-edge-operation strong{font:10px var(--mono)}.cycle-movements{border-top:1px solid var(--line);background:#f6f2e9;justify-content:center;gap:8px;padding:9px 18px;display:flex}.cycle-movements span{font:7px var(--mono);border:1px solid #d5d0c5;align-items:center;gap:9px;padding:6px 10px;display:flex}.cycle-movements b{color:var(--blue)}.cycle-movements i{color:#747983;font-style:normal}.cycle-movements strong{color:var(--coral)}.detached-nodes{border-top:1px dashed #999;align-items:center;gap:18px;margin-top:48px;padding-top:22px;display:flex}.detached-nodes>span{color:#747983;width:105px;font:7px/1.5 var(--mono)}.linked-code ol{margin-top:45px}.linked-code li{min-height:60px}.sort-stage{background-image:linear-gradient(#3644560d 1px,#0000 1px),linear-gradient(90deg,#3644560d 1px,#0000 1px);background-size:23px 23px;height:390px;padding:58px 42px 25px;position:relative;overflow:hidden}.pass-indicator{background:var(--ink);color:#fff;font:8px var(--mono);letter-spacing:.1em;padding:5px 8px;position:absolute;top:18px;right:20px}.sort-stage.is-playing .pass-indicator:before{content:"";background:var(--coral);border-radius:50%;width:5px;height:5px;margin-right:6px;animation:1.1s ease-out infinite playback-pulse;display:inline-block;box-shadow:0 0 #ff655c99}.array-tape{z-index:3;align-items:center;gap:10px;display:flex;position:absolute;top:13px;left:20px}.array-tape>span{color:#747983;font:7px var(--mono);letter-spacing:.09em;white-space:nowrap}.tape-cells{gap:3px;width:clamp(150px,25vw,265px);display:grid}.tape-cell{min-width:0;height:31px;color:var(--ink);background:#fffdf8e6;border:1px solid #19202b4d;grid-template-rows:1fr auto;place-items:center;font-style:normal;transition:opacity .22s,background .22s,border-color .22s,transform .26s;display:grid}.tape-cell b{font:8px var(--mono);align-self:end}.tape-cell small{color:#93969c;font:5px var(--mono);align-self:start}.tape-cell.is-range-inactive{opacity:.26}.tape-cell.is-compared{border-color:var(--gold);box-shadow:0 3px 0 var(--gold);background:#fff1bd;transform:translateY(-3px)}.tape-cell.is-swapped{border-color:var(--coral);background:var(--coral);color:#fff}.tape-cell.is-merged{border-color:var(--blue);background:var(--blue);color:#fff}.tape-cell.is-sorted{color:#fff;background:#65aa84;border-color:#4b946c}.tape-cell.starts-right-half{margin-left:5px}.sort-bars{border-bottom:2px solid var(--ink);justify-content:center;align-items:flex-end;gap:clamp(7px,1.4vw,17px);height:258px;display:flex}.bar-slot{flex-direction:column;justify-content:flex-end;align-items:center;width:min(76px,13%);height:100%;display:flex;position:relative}.bar-slot>span{color:#8b8e94;font:8px var(--mono);position:absolute;bottom:-23px}.sort-bar{border:1px solid var(--ink);width:100%;min-height:70px;color:var(--ink);background:#e6b143;place-items:start center;padding-top:13px;transition:height .35s cubic-bezier(.22,.9,.32,1),background .22s,transform .36s cubic-bezier(.2,.9,.25,1),opacity .3s,filter .3s,box-shadow .3s;display:grid;position:relative;box-shadow:4px 0 #19202b21}.sort-bar strong{font:13px var(--mono)}.bar-state-marker{color:currentColor;font:6px var(--mono);letter-spacing:.04em;text-align:center;text-overflow:ellipsis;position:absolute;bottom:4px;left:3px;right:3px;overflow:hidden}.sort-bar.is-range-inactive{opacity:.3;filter:grayscale(.4)}.sort-stage.mode-search .sort-bar.is-range-active{box-shadow:4px 0 #19202b21,0 0 0 4px #4e82f712}.sort-stage.mode-search .sort-bar.is-range-inactive{opacity:.16;filter:grayscale();transform:translateY(17px)scale(.82)}.sort-stage.mode-search .tape-cell.is-range-inactive{opacity:.18;transform:scale(.84)}.sort-stage.mode-search .sort-bar.is-compared{animation:.52s cubic-bezier(.2,.9,.25,1) both midpoint-focus;box-shadow:4px 0 #19202b21,0 0 0 7px #e6b14333}.sort-bar.is-merged{background:var(--blue);color:#fff}.sort-bar.is-compared{outline:3px solid var(--gold);outline-offset:2px;background:#fff1bd;transform:translateY(-8px)}.sort-bar.is-swapped{background:var(--coral);color:#fff;transform:translateY(-12px)}.sort-bar.is-sorted{color:#fff;background:#65aa84}.sort-bar.is-swapped{border-style:dashed}.sort-bar.is-merged{border-style:double;border-width:2px}.sort-bar.is-sorted{border-width:2px}.sort-bar.is-swapped.arrives-from-right{animation:.52s cubic-bezier(.2,.9,.25,1) both arrive-from-right}.sort-bar.is-swapped.arrives-from-left{animation:.52s cubic-bezier(.2,.9,.25,1) both arrive-from-left}.tape-cell.is-swapped.arrives-from-right{animation:.44s cubic-bezier(.2,.9,.25,1) both tape-from-right}.tape-cell.is-swapped.arrives-from-left{animation:.44s cubic-bezier(.2,.9,.25,1) both tape-from-left}.sort-bar.is-merged,.tape-cell.is-merged{animation:.43s cubic-bezier(.2,.9,.25,1) both merge-settle;animation-delay:calc(var(--item-index) * 28ms)}.bar-slot.starts-right-half{margin-left:clamp(4px,.8vw,11px)}.visual-legend{color:#747983;font:8px var(--mono);justify-content:center;gap:18px;margin-top:37px;display:flex}.visual-legend span{align-items:center;gap:5px;display:flex}.visual-legend i{border:1px solid var(--ink);width:8px;height:8px}.legend-candidate{background:#4e82f747}.legend-compare{background:#fff1bd}.legend-swap{background:var(--coral)}.legend-merged{background:var(--blue)}.legend-sorted{background:#65aa84}.step-narration{border-top:1px solid var(--line);background:#fbf8f1;grid-template-columns:36px 1fr;gap:14px;min-height:90px;padding:17px 23px;display:grid}.step-narration>span{color:var(--coral);font:11px var(--mono)}.step-narration strong{margin-bottom:5px;font-size:12px;display:block}.step-narration p{color:#6b7079;margin:0;font-size:10px;line-height:1.55}.step-narration{animation:.26s ease-out both narration-in}.player-controls{border-top:1px solid var(--line);justify-content:center;align-items:center;gap:8px;min-height:73px;display:flex}.control-button,.speed-button,.play-button{border:1px solid var(--line);background:var(--paper);cursor:pointer;height:37px}.control-button{border-radius:50%;width:37px}.control-button:disabled{opacity:.3;cursor:not-allowed}.play-button{border-color:var(--ink);background:var(--ink);color:#fff;justify-content:center;align-items:center;gap:8px;min-width:105px;padding:0 18px;font-size:10px;font-weight:700;display:flex}.play-button span{color:var(--coral)}.play-button.is-playing span{animation:.9s ease-in-out infinite alternate playing-mark}.speed-button{font:8px var(--mono);padding:0 11px}.timeline{background:#e4dfd5;height:4px}.timeline span{background:var(--coral);height:100%;transition:width .25s;display:block}.shortcut-strip{border-top:1px solid var(--line);color:#777c84;min-height:42px;font:8px var(--mono);background:#f6f2e9;justify-content:center;align-items:center;gap:18px;padding:8px 18px;display:flex}.shortcut-strip span{white-space:nowrap;align-items:center;gap:5px;display:inline-flex}.shortcut-strip kbd{background:var(--paper);min-width:21px;color:var(--ink);font:8px var(--mono);text-align:center;border:1px solid #19202b38;border-bottom-width:2px;border-radius:3px;padding:3px 5px}.code-panel{color:#fff;background:#18212c;min-width:0}.code-panel .panel-label{color:#a9afb7;border-color:#ffffff24}.code-panel ol{counter-reset:code;margin:24px 0 0;padding:0;list-style:none}.code-panel li{color:#b8bec5;border-left:3px solid #0000;grid-template-columns:25px 1fr;align-items:center;min-height:43px;padding:0 20px;transition:background .18s,color .18s;display:grid}.code-panel li.is-active{border-left-color:var(--coral);color:#fff;background:#ff655c21}.code-panel li.is-active code{animation:.26s ease-out both code-line-in}.code-panel li>span{color:#69717b;font:8px var(--mono)}.code-panel code{color:inherit;font:10px/1.4 var(--mono);white-space:pre;text-overflow:ellipsis;background:0 0;overflow:hidden}.insight-note{background:#ffffff0a;border:1px solid #ffffff2b;margin:37px 23px 23px;padding:18px}.insight-note span{color:var(--coral);font:8px var(--mono);letter-spacing:.12em}.insight-note p{color:#b8bdc4;margin:9px 0 0;font-size:10px;line-height:1.65}.lesson-concept{border:1px solid var(--line);background:#fffdf8a6;grid-template-columns:80px minmax(260px,.9fr) minmax(280px,1fr);align-items:center;gap:55px;margin-top:65px;padding:85px 7%;display:grid}.concept-number{color:#19202b2b;font:52px var(--mono)}.lesson-concept h2{letter-spacing:-.045em;max-width:500px;margin:0;font-size:clamp(30px,3.6vw,48px);line-height:1.04}.lesson-concept>p{color:#686e77;margin:0;font-size:13px;line-height:1.8}.prediction-checkpoint{color:#fff;background:#17202b;border:1px solid #17202b;margin-top:22px;padding:58px 7%}.checkpoint-heading{grid-template-columns:80px 1fr;align-items:start;gap:55px;display:grid}.checkpoint-number{color:#fff3;font:52px var(--mono)}.checkpoint-heading .eyebrow{color:#aeb5be;margin-bottom:14px}.checkpoint-heading h2{color:#fff;letter-spacing:-.045em;margin:0;font-size:clamp(30px,3.6vw,48px);line-height:1.04}.checkpoint-heading>div>p:last-child{color:#abb2bb;margin:13px 0 0;font-size:12px}.prediction-checkpoint fieldset{border:0;margin:45px 0 0 135px;padding:0}.prediction-checkpoint legend{color:#fff;max-width:760px;margin-bottom:22px;font-size:17px;font-weight:700;line-height:1.5}.prediction-options{grid-template-columns:repeat(2,minmax(0,1fr));gap:10px;display:grid}.prediction-options button{color:#dce0e5;cursor:pointer;text-align:left;background:#ffffff09;border:1px solid #fff3;grid-template-columns:27px 1fr 22px;align-items:center;gap:10px;min-height:62px;padding:12px 15px;font-size:10px;line-height:1.5;transition:border-color .16s,background .16s,transform .16s;display:grid}.prediction-options button:hover:not(:disabled){border-color:#ffffffa6;transform:translateY(-2px)}.prediction-options button>span{color:#aeb5be;width:25px;height:25px;font:9px var(--mono);border:1px solid #ffffff40;place-items:center;display:grid}.prediction-options button i{border-radius:50%;place-items:center;width:20px;height:20px;font-style:normal;display:grid}.prediction-options button.is-wrong{border-color:var(--coral);background:#ff655c1a}.prediction-options button.is-wrong i{background:var(--coral);color:#fff}.prediction-options button.is-correct{color:#fff;background:#65aa8424;border-color:#65aa84}.prediction-options button.is-correct i{color:#fff;background:#65aa84}.prediction-options button:disabled{cursor:default;opacity:.52}.prediction-options button.is-correct:disabled{opacity:1}.checkpoint-feedback{background:#ffffff0d;border-left:3px solid;justify-content:space-between;align-items:center;gap:30px;margin:14px 0 0 135px;padding:18px 20px;display:flex}.checkpoint-feedback.is-hint{border-color:var(--gold)}.checkpoint-feedback.is-success{border-color:#65aa84}.checkpoint-feedback strong{color:#fff;font-size:11px;display:block}.checkpoint-feedback p{color:#b8bec6;margin:6px 0 0;font-size:10px;line-height:1.6}.checkpoint-feedback>button{color:#fff;cursor:pointer;font:8px var(--mono);text-transform:uppercase;background:0 0;border:1px solid #ffffff4d;flex:none;padding:8px 10px}@keyframes spin{to{transform:rotate(360deg)}}@keyframes pulse{75%,to{box-shadow:0 0 0 10px #54a37800}}@keyframes bars{0%,to{transform:translateY(0)}44%{transform:translateY(-8px)}52%{transform:translateY(0)}}@keyframes arrive-from-right{0%{opacity:.55;transform:translateX(var(--swap-from)) translateY(-20px) rotate(3deg)}72%{transform:translate(0)translateY(-16px)rotate(-1deg)}to{opacity:1;transform:translate(0)translateY(-12px)rotate(0)}}@keyframes arrive-from-left{0%{opacity:.55;transform:translateX(var(--swap-from)) translateY(-20px) rotate(-3deg)}72%{transform:translate(0)translateY(-16px)rotate(1deg)}to{opacity:1;transform:translate(0)translateY(-12px)rotate(0)}}@keyframes tape-from-right{0%{opacity:.5;transform:translateX(var(--swap-from)) scale(.88)}to{opacity:1;transform:translate(0)scale(1)}}@keyframes tape-from-left{0%{opacity:.5;transform:translateX(var(--swap-from)) scale(.88)}to{opacity:1;transform:translate(0)scale(1)}}@keyframes merge-settle{0%{opacity:.45;transform:translateY(-14px)scale(.92);box-shadow:0 10px #4e82f72e}to{opacity:1;transform:translateY(0)scale(1);box-shadow:4px 0 #19202b21}}@keyframes narration-in{0%{opacity:.35;transform:translateY(5px)}to{opacity:1;transform:translateY(0)}}@keyframes code-line-in{0%{opacity:.45;transform:translate(8px)}to{opacity:1;transform:translate(0)}}@keyframes playback-pulse{to{box-shadow:0 0 0 7px #ff655c00}}@keyframes playing-mark{to{opacity:.45}}@keyframes midpoint-focus{0%{transform:translateY(2px)scale(.94)}65%{transform:translateY(-12px)scale(1.04)}to{transform:translateY(-8px)scale(1)}}@keyframes memory-cell-in{0%{opacity:.35;transform:translateY(-6px)}to{opacity:1;transform:translateY(0)}}@keyframes pointer-pulse{to{opacity:.48;text-shadow:0 0 14px #ff655cb3}}@media (width<=980px){.hero-section{grid-template-columns:1fr;min-height:auto;padding-top:65px}.hero-copy{max-width:710px}.hero-illustration{min-height:470px}.chapter-card{grid-column:span 3}.chapter-card:last-child{grid-column:span 6}.lesson-catalogue-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.lesson-workspace,.growth-workspace{grid-template-columns:1fr}.growth-panel{border-right:0}.growth-guide{min-height:480px}.visualizer-panel{border-right:0}.code-panel{min-height:500px}.lesson-concept{grid-template-columns:60px 1fr}.lesson-concept>p{grid-column:2}.checkpoint-heading{grid-template-columns:60px 1fr}.prediction-checkpoint fieldset,.checkpoint-feedback{margin-left:115px}.problem-brief{grid-template-columns:125px 1fr}.problem-brief-story{border-right:0}.problem-brief-constraints{border-top:1px solid var(--line);grid-column:1/-1}.problem-brief-constraints ul{grid-template-columns:repeat(3,1fr)}.problem-brief-question{grid-column:1/-1}}@media (width<=680px){.topbar{height:70px;padding:0 18px}.brand small,.progress-copy,.menu-button>span:not(.menu-icon),.menu-button kbd{display:none}.lesson-search{width:calc(100vw - 36px);max-height:calc(100vh - 78px);padding:20px;top:58px;right:18px}.menu-button{justify-content:center;width:42px}.hero-section{gap:25px;padding:48px 20px 65px}.hero-copy h1{font-size:45px}.hero-actions{flex-direction:column;align-items:flex-start}.hero-illustration{min-height:370px}.grid-paper{inset:3% 0 0}.array-stage{width:92%;min-height:240px;padding:20px}.array-bars{gap:5px;height:150px}.orbit-one{width:310px;height:310px}.orbit-two{width:250px;height:250px}.learning-path{padding:70px 20px}.section-heading{grid-template-columns:1fr;gap:22px}.chapter-grid{grid-template-columns:1fr}.chapter-card,.chapter-card:nth-child(4),.chapter-card:nth-child(5),.chapter-card:last-child{grid-column:auto;min-height:300px}.principles{grid-template-columns:1fr;padding:0 20px 70px}.principles div{border-right:1px solid var(--line);border-bottom:0}.principles div:last-child{border-bottom:1px solid var(--line)}footer{text-align:center;grid-template-columns:1fr;gap:22px;padding:35px 20px}footer>span{text-align:center}.footer-brand{justify-content:center}.lesson-page,.catalogue-page{padding:22px 14px 70px}.catalogue-heading{grid-template-columns:1fr;gap:28px;min-height:370px;padding:45px 0}.catalogue-heading h1{font-size:53px}.catalogue-progress{width:170px}.lesson-catalogue-grid,.problem-brief{grid-template-columns:1fr}.problem-brief-label{border-right:0;flex-direction:row;align-items:center;min-height:68px;padding:15px 18px}.problem-brief-story,.problem-brief-constraints,.problem-brief-question{grid-column:1}.problem-brief-story{padding:20px}.problem-brief-constraints{padding:18px 20px}.problem-brief-constraints ul{grid-template-columns:1fr}.problem-brief-question{grid-template-columns:1fr;gap:8px;padding:18px 20px}.growth-bars{gap:25px;min-height:360px;padding:30px 18px}.input-size-experiment{grid-template-columns:32px minmax(0,1fr) 32px 54px;padding:12px 14px}.input-size-experiment>div{grid-column:1/-1}.growth-row{grid-template-columns:78px minmax(0,1fr) 30px;gap:8px}.growth-row strong{font-size:8px}.growth-guide li{grid-template-columns:62px 1fr}.operation-stage{gap:38px;min-height:360px;padding:38px 18px}.operation-conclusion{gap:4px}.operation-conclusion span,.operation-conclusion strong,.operation-conclusion em{padding:7px 5px;font-size:8px}.memory-stage{min-height:360px;padding:30px 16px}.memory-row{grid-template-columns:78px minmax(0,1fr) 22px;gap:7px}.memory-row strong{font-size:8px}.memory-cells{gap:2px}.memory-cells i{min-width:10px;font-size:6px}.recursion-stage{grid-template-columns:80px minmax(0,1fr);gap:15px;min-height:410px;padding:25px 16px}.call-stack>div>span{padding:6px}.call-stack>div>span b{font-size:7px}.tradeoff-stage{grid-template-columns:1fr;min-height:560px;padding:28px 18px}.tradeoff-stage article{min-height:190px}.lesson-catalogue-card,.lesson-catalogue-card:last-child:nth-child(odd){grid-column:auto;min-height:370px}.catalogue-note{grid-template-columns:1fr;gap:12px}.not-found-page{min-height:calc(100vh - 215px);padding:75px 22px}.not-found-page>div{flex-direction:column;align-items:flex-start}.lesson-crumbs span:not(:last-child){display:none}.lesson-switcher{justify-content:flex-start;margin-top:22px;overflow-x:auto}.lesson-switcher button{white-space:nowrap}.lesson-heading{min-height:220px}.lesson-heading h1{font-size:51px}.lesson-heading>div>p:last-child{max-width:250px;line-height:1.6}.complexity-stamp{width:92px;height:92px}.complexity-stamp strong{font-size:18px}.complexity-stamp strong.is-long{font-size:13px}.sort-stage{height:350px;padding:58px 18px 20px}.panel-label{padding:0 12px}.panel-actions{gap:4px}.panel-label button{padding:5px 6px}.array-input-panel{grid-template-columns:1fr;gap:10px;padding:14px 12px}.array-input-field{grid-template-columns:minmax(0,1fr) auto}.array-input-field button:last-child{grid-column:1/-1}.array-input-error{grid-column:1;margin-top:0}.search-input-panel{grid-template-columns:minmax(0,1fr) 78px;gap:10px;padding:14px 12px}.search-input-copy,.search-input-panel label:first-of-type,.search-input-actions,.search-input-panel .array-input-error{grid-column:1/-1}.linked-experiment{grid-template-columns:1fr 1fr}.linked-experiment>div{grid-column:1/-1}.linked-experiment>button{align-self:end}.linked-experiment>p{grid-column:1/-1}.linked-delete-experiment{grid-template-columns:1fr 70px}.linked-search-experiment,.stack-experiment,.queue-experiment,.linked-cycle-experiment{grid-template-columns:1fr 1fr}.traversal-registers{gap:5px;padding-inline:12px}.traversal-registers>span{padding-inline:7px;display:grid}.linked-state-legend{gap:7px;right:14px}.linked-stage{min-height:410px;padding-left:18px}.sort-bars{gap:7px;height:220px}.array-tape{gap:0;left:13px}.array-tape>span{display:none}.tape-cells{gap:2px;width:min(215px,58vw)}.tape-cell{height:29px}.visual-legend{gap:9px}.player-controls{gap:5px}.speed-button{padding:0 6px}.shortcut-strip{justify-content:flex-start;gap:12px;overflow-x:auto}.lesson-concept{grid-template-columns:1fr;gap:25px;padding:50px 28px}.lesson-concept>p{grid-column:auto}.concept-number{font-size:38px}.prediction-checkpoint{padding:48px 22px}.checkpoint-heading{grid-template-columns:1fr;gap:20px}.checkpoint-number{font-size:38px}.prediction-checkpoint fieldset{margin:35px 0 0}.prediction-checkpoint legend{font-size:15px}.prediction-options{grid-template-columns:1fr}.checkpoint-feedback{flex-direction:column;align-items:flex-start;gap:15px;margin:12px 0 0}}