/* System fonts keep the foundation self-contained. */
:root{color-scheme:light;--bg:#faf9fc;--surface:#fff;--ink:#262331;--muted:#757181;--line:#e8e5ee;--accent:#7352cf;--accent-soft:#f0ebfb;--card:#f5f1fd;--shadow:0 16px 50px #32205208}
@media(prefers-color-scheme:dark){:root:not([data-theme="light"]){color-scheme:dark;--bg:#17151d;--surface:#1d1a24;--ink:#ece8f5;--muted:#aaa3b9;--line:#34303f;--accent:#b799ff;--accent-soft:#2c2341;--card:#211b2e;--shadow:none}}
:root[data-theme="dark"]{color-scheme:dark;--bg:#17151d;--surface:#1d1a24;--ink:#ece8f5;--muted:#aaa3b9;--line:#34303f;--accent:#b799ff;--accent-soft:#2c2341;--card:#211b2e;--shadow:none}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--ink);font-family:Inter,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;font-size:17px;line-height:1.65}a{color:inherit;text-decoration:none}button,select{font:inherit}button,a,select{-webkit-tap-highlight-color:transparent}a:focus-visible,button:focus-visible,select:focus-visible{outline:3px solid var(--accent);outline-offset:5px}::selection{background:var(--accent-soft)}.skip-link{position:fixed;top:-100px;left:16px;background:var(--surface);padding:12px;z-index:10}.skip-link:focus{top:12px}.site-header{border-bottom:1px solid var(--line);background:var(--surface)}.header-inner{max-width:1240px;min-height:84px;margin:auto;padding:0 36px;display:flex;align-items:center;gap:40px}.brand{display:flex;align-items:center;gap:12px;font-size:20px;font-weight:750;letter-spacing:-.5px;white-space:nowrap}.brand-light{font-weight:450}.brand-mark{width:32px;height:34px;background:linear-gradient(135deg,#bb77ea,#7352cf);color:white;display:grid;place-items:center;font-size:24px;font-weight:800;border-radius:7px}.site-nav{display:flex;align-items:center;gap:28px;margin-left:auto;height:84px;font-size:14px;font-weight:600}.site-nav a{height:100%;display:flex;align-items:center;border-bottom:2px solid transparent;color:var(--muted)}.site-nav a:hover,.site-nav .active{color:var(--ink)}.site-nav .active{border-color:var(--accent)}.theme-control{display:flex;align-items:center;gap:9px;padding-left:24px;border-left:1px solid var(--line);font-size:12px;color:var(--muted)}select{background:var(--bg);color:var(--ink);border:1px solid var(--line);border-radius:7px;padding:7px;font-size:12px;cursor:pointer}.menu-toggle{display:none}.page{max-width:1240px;margin:auto;padding:0 36px}.hero{display:grid;grid-template-columns:1.2fr 1fr;gap:80px;padding:78px 0 72px;align-items:center}.eyebrow{font-size:10px;font-weight:750;letter-spacing:1.7px;color:var(--muted);margin:0 0 22px;display:flex;align-items:center;gap:9px}.tiny-dot{width:6px;height:6px;background:var(--accent);border-radius:50%}h1,h2,h3,p{margin-top:0}h1{font-size:64px;line-height:1.08;letter-spacing:-3px;font-weight:760;margin-bottom:25px}.accent{color:var(--accent)}.hero-description{max-width:520px;color:var(--muted);font-size:17px;line-height:1.75;margin-bottom:28px}.button-primary{display:inline-flex;gap:30px;align-items:center;background:var(--ink);color:var(--bg);padding:13px 23px;border-radius:8px;font-size:14px;font-weight:600}.button-primary:hover{background:var(--accent);color:var(--surface)}.availability{font-size:12px;color:var(--muted);margin:16px 0 0}.study-card{background:var(--card);border:1px solid var(--line);border-radius:16px;padding:32px;box-shadow:var(--shadow)}.card-top{display:flex;align-items:center;justify-content:space-between}.card-top .eyebrow{margin:0;font-size:9px;letter-spacing:1.2px}.code-symbol{font-family:"JetBrains Mono",monospace;font-size:25px;color:var(--accent)}.study-card h2{font-size:28px;line-height:1.3;letter-spacing:-1px;margin:26px 0}.study-steps{list-style:none;padding:0;margin:0}.study-steps li{display:flex;gap:16px;padding:15px 0;border-top:1px solid var(--line)}.step-number{font-family:"JetBrains Mono",monospace;font-size:12px;color:var(--accent);padding-top:3px}.study-steps h3{font-size:14px;font-weight:650;margin:0 0 3px}.study-steps p{font-size:12px;color:var(--muted);margin:0}.card-bottom{margin-top:20px;padding-top:18px;border-top:1px solid var(--line);display:flex;gap:14px;font-family:"JetBrains Mono",monospace;color:var(--accent);font-size:9px;letter-spacing:1px}.topics-section{border-top:1px solid var(--line);padding:38px 0}.section-heading{display:flex;justify-content:space-between;align-items:flex-end;gap:20px;margin-bottom:24px}.section-heading .eyebrow{margin-bottom:8px}.section-heading h2{font-size:26px;letter-spacing:-.8px;margin:0;line-height:1.3}.muted{color:var(--muted);font-size:12px}.topic-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:15px}.topic-card{padding:24px 22px;background:var(--surface);border:1px solid var(--line);border-radius:10px}.topic-number{font-family:"JetBrains Mono",monospace;color:var(--accent);font-size:12px}.topic-card h3{font-size:17px;margin:17px 0 10px;font-weight:650;line-height:1.35}.topic-card p{font-size:13px;color:var(--muted);line-height:1.7;margin-bottom:22px}.topic-card .topic-tags{font-family:"JetBrains Mono",monospace;font-size:9px;line-height:1.8;color:var(--accent);margin:0}.latest-section{padding:30px 0 68px}.text-link{font-size:12px;color:var(--accent);font-weight:600}.empty-state{display:flex;align-items:center;justify-content:center;flex-direction:column;text-align:center;gap:20px;padding:76px 30px;border:1px dashed var(--line);border-radius:10px;background:var(--surface)}.empty-icon{font-family:"JetBrains Mono",monospace;font-size:25px;color:var(--accent);background:var(--accent-soft);border-radius:12px;width:74px;height:66px;display:grid;place-items:center}.empty-state h2{font-size:21px;letter-spacing:-.4px;margin:0 0 6px}.empty-state p{max-width:440px;font-size:13px;color:var(--muted);margin:0}.empty-state.compact{flex-direction:row;text-align:left;padding:30px;justify-content:flex-start}.compact .empty-icon{flex-shrink:0}.compact h2{font-size:16px}.compact p{max-width:none;font-size:12px}.site-footer{border-top:1px solid var(--line)}.footer-inner{max-width:1240px;margin:auto;padding:26px 36px;display:flex;justify-content:space-between;gap:20px;font-size:11px;color:var(--muted)}.footer-inner span:first-child{font-weight:650;color:var(--ink)}.catalog-header{padding:65px 0 30px}.catalog-header h1{font-size:48px;letter-spacing:-2px}.catalog-header .hero-description{max-width:600px}.catalog-toolbar{display:flex;align-items:center;gap:12px;border-bottom:1px solid var(--line);padding-bottom:18px;margin-bottom:24px;font-size:13px;font-weight:600}.catalog-toolbar .muted{margin-left:auto;font-weight:400}.count-badge{background:var(--accent-soft);color:var(--accent);border-radius:5px;padding:1px 8px;font-size:11px}.catalog-toolbar+.empty-state{margin-bottom:80px}.error-page{padding:110px 0;min-height:70vh}.error-page h1{font-size:42px;letter-spacing:-1.5px}.error-page p{color:var(--muted)}
@media(min-width:701px){.site-nav{display:flex!important}}
@media(max-width:1000px){.hero{gap:30px}h1{font-size:52px}.study-card{padding:24px}.topic-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:700px){.header-inner{padding:16px 20px;min-height:72px;gap:14px;flex-wrap:wrap}.brand{font-size:17px}.brand-mark{width:26px;height:28px;font-size:20px}.theme-control{padding-left:0;border:0;margin-left:auto}.theme-control label{display:none}.enhanced .menu-toggle{display:block;background:transparent;border:1px solid var(--line);border-radius:7px;padding:6px 10px;color:var(--ink);font-size:12px;cursor:pointer;order:3}.site-nav{width:100%;height:auto;order:4;margin:0;gap:24px}.site-nav a{padding:10px 0}.enhanced .site-nav{display:none}.enhanced .site-nav.is-open{display:flex}.page{padding:0 20px}.hero{grid-template-columns:1fr;padding:44px 0 40px;gap:32px}h1{font-size:46px;letter-spacing:-2px}.hero-description{font-size:16px}.eyebrow{font-size:9px;letter-spacing:1.2px}.study-card h2{font-size:25px}.section-heading{align-items:flex-start}.section-heading>.muted{display:none}.section-heading h2{font-size:23px}.topic-grid{gap:12px}.topic-card{padding:18px 16px}.topic-card h3{font-size:16px}.topic-card p{font-size:12px}.latest-section{padding:18px 0 40px}.empty-state.compact{padding:24px 18px;align-items:flex-start;gap:16px}.compact .empty-icon{width:50px;height:50px;font-size:19px}.footer-inner{padding:24px 20px;flex-direction:column;gap:4px}.catalog-header{padding:40px 0 16px}.catalog-header h1{font-size:40px}.catalog-toolbar .muted{font-size:10px}.empty-state{padding:52px 20px}.error-page{padding:70px 0}.error-page h1{font-size:34px}}
@media(max-width:400px){.header-inner{gap:10px}.brand{gap:8px;font-size:16px}.topic-grid{grid-template-columns:1fr}.card-bottom{gap:10px}h1{font-size:43px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}

.lecture-cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;margin-bottom:60px}.lecture-card{background:var(--surface);border:1px solid var(--line);border-radius:10px;padding:26px}.lecture-card h2{font-size:22px;line-height:1.3;letter-spacing:-.5px}.lecture-card p{font-size:14px;color:var(--muted)}.lecture-card-bottom{display:flex;justify-content:space-between;gap:12px}.lecture-layout{display:grid;grid-template-columns:185px minmax(0,1fr) 155px;gap:28px;padding:38px 0 70px}.lecture-sidebar,.desktop-toc{position:sticky;top:24px;align-self:start;font-size:12px}.lecture-nav-link{display:flex;gap:12px;padding:12px 8px;color:var(--muted);border-radius:6px;line-height:1.4}.lecture-nav-link[aria-current]{background:var(--accent-soft);color:var(--accent)}.lecture-nav-link:hover{color:var(--ink)}.lecture-content{min-width:0;font-size:17px;line-height:1.7}.lecture-header h1{font-size:38px;letter-spacing:-1.5px;line-height:1.2}.lecture-tags{display:flex;gap:8px;flex-wrap:wrap;margin:20px 0 32px}.lecture-tags span{font-size:11px;padding:3px 9px;border-radius:5px;background:var(--accent-soft);color:var(--accent)}.lecture-content h2{font-size:28px;letter-spacing:-.6px;border-top:1px solid var(--line);padding-top:26px;margin-top:36px}.lecture-content h3{font-size:22px;margin-top:28px}.lecture-content h4{font-size:18px}.lecture-content :is(h2,h3,h4){scroll-margin-top:24px}.lecture-content a:not(.previous-next a){color:var(--accent);text-decoration:underline;text-underline-offset:3px}.lecture-content :not(pre)>code{background:var(--accent-soft);padding:2px 5px;border-radius:4px}.lecture-content code{font-family:"JetBrains Mono",ui-monospace,SFMono-Regular,Consolas,monospace;font-size:.85em}.code-block,.markdown-block pre{max-width:100%;overflow-x:auto;padding:20px;border:1px solid var(--line);border-radius:8px;background:var(--surface);line-height:1.65;font-size:14px;tab-size:4}.markdown-block{overflow-wrap:anywhere}.markdown-block table{display:block;overflow-x:auto;border-collapse:collapse;font-size:14px}.markdown-block th,.markdown-block td{border:1px solid var(--line);padding:9px 14px}.markdown-block blockquote{margin:20px 0;padding:12px 20px;border-left:3px solid var(--line);color:var(--muted)}.callout{border-left:3px solid var(--accent);border-radius:0 8px 8px 0;background:var(--accent-soft);padding:16px 20px;margin:24px 0}.callout-label{font-size:10px!important;letter-spacing:1.3px;color:var(--accent);font-weight:700;margin:0 0 8px}.callout p:last-child{margin-bottom:0}.callout-warning{border-color:#b47d26}.playground-preview{border:1px solid var(--line);border-radius:10px;padding:18px;margin:24px 0}.playground-preview pre{margin:12px 0}.toc{display:flex;flex-direction:column;gap:9px}.toc-link{color:var(--muted);line-height:1.45;font-size:12px}.toc-link.depth-3{padding-left:12px}.toc-link[aria-current]{color:var(--accent);font-weight:600}.previous-next{display:flex;gap:16px;justify-content:space-between;border-top:1px solid var(--line);margin-top:40px;padding-top:24px}.previous-next a{display:flex;flex-direction:column;max-width:48%;font-size:13px}.previous-next strong{font-size:16px}.previous-next span{color:var(--muted);font-size:11px}.lecture-mobile-tools,.mobile-toc{display:none}#lecture-menu{background:var(--surface);color:var(--ink);border:1px solid var(--line);border-radius:12px;max-width:calc(100vw - 32px);width:340px;max-height:80vh;overflow:auto;padding:24px}#lecture-menu::backdrop{background:#15101b88}#lecture-menu h2{font-size:24px}#lecture-menu-close,.lecture-mobile-tools button{padding:8px 14px;border:1px solid var(--line);border-radius:7px;background:var(--surface);color:var(--ink);cursor:pointer;font-size:13px}.lecture-mobile-tools button{display:none}.enhanced .lecture-mobile-tools button{display:inline-block}
@media(max-width:1100px){.lecture-layout{grid-template-columns:165px minmax(0,1fr)}.desktop-toc{display:none}.mobile-toc{display:block;border:1px solid var(--line);border-radius:8px;padding:14px;margin:24px 0}.mobile-toc summary{font-size:13px;cursor:pointer}.mobile-toc .toc{margin-top:16px}.lecture-cards{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:700px){.lecture-layout{grid-template-columns:minmax(0,1fr);padding-top:20px}.lecture-sidebar{position:static;grid-row:1}.enhanced .lecture-sidebar{display:none}.lecture-content{font-size:16px}.lecture-header h1{font-size:32px}.lecture-mobile-tools{display:block;padding-top:24px}.lecture-cards{grid-template-columns:minmax(0,1fr)}.previous-next strong{font-size:14px}}

.hljs-keyword,.hljs-literal{color:var(--accent);font-weight:600}.hljs-string{color:#26714a}.hljs-comment{color:var(--muted);font-style:italic}.hljs-number,.hljs-title{color:#9a4d16}:root[data-theme=dark] .hljs-string{color:#8bd1aa}:root[data-theme=dark] .hljs-number,:root[data-theme=dark] .hljs-title{color:#edb581}
@media(prefers-color-scheme:dark){:root:not([data-theme=light]) .hljs-string{color:#8bd1aa}:root:not([data-theme=light]) .hljs-number,:root:not([data-theme=light]) .hljs-title{color:#edb581}}
@media(max-width:700px){#lecture-menu{margin:0;height:100dvh;max-height:100dvh;width:min(340px,calc(100vw - 30px));border-radius:0;border:0;border-right:1px solid var(--line)}}

.language-control{display:flex;gap:10px;align-items:center;font-size:12px;white-space:nowrap}.language-control a{color:var(--muted)}.language-control a[aria-current]{color:var(--accent);font-weight:600}.language-control span[aria-disabled]{opacity:.5}.language-control a:focus-visible{outline:2px solid var(--accent);outline-offset:4px;border-radius:2px}
@media(max-width:700px){.header-inner{flex-wrap:wrap}.language-control{order:4;flex-basis:100%;justify-content:flex-end;padding-bottom:6px}.theme-control{margin-left:auto}.site-nav{order:5}.brand{flex-shrink:0}}