@import url('https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;600;700&family=Space+Grotesk:wght@400;600;700&display=swap');:root{--bg:#050a13;--panel:#091222;--cyan:#00f0ff;--text:#f4f7fb;--muted:#91a0b7;--line:#173047;--green:#00ff75}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background-color:var(--bg);background-image:linear-gradient(rgba(0,240,255,.035) 1px,transparent 1px),linear-gradient(90deg,rgba(0,240,255,.035) 1px,transparent 1px);background-size:42px 42px;color:var(--text);font-family:"Space Grotesk",sans-serif}.lesson-shell{width:min(1080px,calc(100% - 36px));margin:auto;padding:56px 0 100px}.lesson-loading{padding:80px 0;color:var(--cyan);font:14px "JetBrains Mono"}.lesson-back{display:inline-flex;margin-bottom:34px;color:var(--muted);text-decoration:none;font:12px "JetBrains Mono"}.lesson-back:hover{color:var(--cyan)}.lesson-hero,.lesson-section{position:relative;border:1px solid var(--line);background:rgba(5,10,19,.92);padding:clamp(24px,5vw,52px);margin-bottom:24px}.lesson-hero{border-color:rgba(0,240,255,.45)}.lesson-kicker,.section-number,.lesson-meta dt{color:var(--cyan);font:700 11px "JetBrains Mono";letter-spacing:.14em;text-transform:uppercase}.lesson-hero h1{max-width:850px;margin:14px 0 18px;font-size:clamp(2.5rem,7vw,5.5rem);line-height:.98;letter-spacing:-.045em}.lesson-intro{max-width:760px;color:var(--muted);font-size:1.1rem;line-height:1.75}.lesson-meta{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;margin:32px 0 0;background:var(--line);border:1px solid var(--line)}.lesson-meta div{background:var(--panel);padding:16px}.lesson-meta dd{margin:6px 0 0;font:600 13px "JetBrains Mono"}.lesson-section h2{margin:8px 0 24px;font-size:clamp(1.8rem,4vw,3rem)}.lesson-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.lesson-card{border:1px solid var(--line);background:var(--panel);padding:20px}.lesson-card b{display:block;margin-bottom:8px;color:var(--cyan);font:700 12px "JetBrains Mono"}.lesson-card p,.lesson-section li{color:var(--muted);line-height:1.7}.lesson-list{display:grid;gap:12px;padding:0;list-style:none;counter-reset:item}.lesson-list li{position:relative;padding:16px 18px 16px 58px;border:1px solid var(--line);background:var(--panel);counter-increment:item}.lesson-list li:before{content:counter(item,decimal-leading-zero);position:absolute;left:18px;color:var(--cyan);font:700 12px "JetBrains Mono"}.lesson-activity{padding:22px;border-left:3px solid var(--green);background:rgba(0,255,117,.05);color:var(--text);line-height:1.8}.resource-list{display:grid;gap:12px}.resource-link{display:flex;justify-content:space-between;gap:16px;padding:16px 18px;border:1px solid var(--line);color:var(--text);text-decoration:none;font:600 13px "JetBrains Mono"}.resource-link:hover{border-color:var(--cyan);color:var(--cyan)}.material-slot{padding:32px;border:1px dashed rgba(0,240,255,.35);color:var(--muted);text-align:center}.material-slot strong{display:block;color:var(--cyan);font:700 13px "JetBrains Mono";margin-bottom:8px}.lesson-nav{display:flex;justify-content:space-between;gap:12px}.lesson-nav a{padding:12px 16px;border:1px solid var(--line);color:var(--muted);text-decoration:none;font:12px "JetBrains Mono"}.lesson-nav a:hover{border-color:var(--cyan);color:var(--cyan)}@media(max-width:760px){.lesson-shell{padding-top:30px}.lesson-meta,.lesson-grid{grid-template-columns:1fr}.lesson-nav{flex-direction:column}.lesson-nav a{text-align:center}}