:root{color-scheme:dark;--bg:#020914;--panel:#071625;--line:#274c67;--blue:#59c9ff;--muted:#9bb4c5;--text:#eff8ff}*{box-sizing:border-box}body{margin:0;background:radial-gradient(circle at 20% 0,#0b2f4c 0,transparent 36%),var(--bg);color:var(--text);font-family:Inter,system-ui,-apple-system,Segoe UI,sans-serif}.ac-head{position:sticky;top:0;z-index:20;display:flex;align-items:center;padding:12px max(18px,calc((100vw - 1240px)/2));border-bottom:1px solid #18384e;background:#020914e8;backdrop-filter:blur(16px)}.ac-head img{width:220px}.ac-head nav{margin-left:auto;display:flex;gap:16px}.ac-head a{color:#cfe0ea;text-decoration:none;font-weight:800}.ac-shell{width:min(1240px,calc(100% - 28px));margin:auto;padding:58px 0 80px}.ac-hero{max-width:900px}.ac-hero>span,.lesson>span,.ac-final>span{color:var(--blue);font-size:10px;font-weight:950;letter-spacing:.14em}.ac-hero h1{font-size:clamp(42px,6vw,74px);line-height:1;margin:12px 0 18px;letter-spacing:-.045em}.ac-hero p{color:#a9bfcd;font-size:17px;line-height:1.75}.ac-progress{display:grid;grid-template-columns:auto 1fr;gap:18px;align-items:center;margin-top:24px}.ac-progress div{display:grid}.ac-progress strong{font-size:28px}.ac-progress span{font-size:11px;color:#8ca8ba}.ac-progress i{height:10px;border-radius:999px;background:rgba(255,255,255,.07);overflow:hidden}.ac-progress b{display:block;height:100%;width:0;background:linear-gradient(90deg,#38aff0,#7de0ff);transition:.3s}.ac-badges{display:flex;flex-wrap:wrap;gap:10px;margin:24px 0}.ac-badges span{padding:9px 12px;border:1px solid #315f7b;border-radius:999px;background:#071827;color:#9fb7c7;font-size:10px;font-weight:900}.ac-badges span.is-earned{border-color:#42c997;color:#b7ffe0;background:#0a2e25}.ac-grid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px}.lesson,.ac-final{padding:22px;border:1px solid var(--line);border-radius:24px;background:linear-gradient(155deg,#091c2d,#05111c)}.lesson h2{margin:7px 0 8px}.lesson p,.lesson li{color:#a6bdcc;line-height:1.65}.lesson ol{padding-left:20px}.quiz{margin-top:16px;padding-top:15px;border-top:1px solid rgba(67,135,177,.22)}.quiz button{display:block;width:100%;margin-top:8px;padding:11px;border:1px solid #315b76;border-radius:12px;background:#071827;color:#dcecf5;text-align:left;font-weight:700}.quiz button.is-correct{border-color:#4ad4a1;background:#0b3529}.quiz button.is-wrong{border-color:#ff747d;background:#3b1419}.lesson.is-complete{box-shadow:inset 0 0 0 1px rgba(64,212,157,.35)}.ac-final{margin-top:18px}.ac-final h2{margin:8px 0 14px}.ac-final div{display:flex;gap:10px;flex-wrap:wrap}.ac-final a{padding:11px 14px;border:1px solid #3283b4;border-radius:12px;background:#0a2134;color:#fff;text-decoration:none;font-weight:850}@media(max-width:760px){.ac-head nav{display:none}.ac-grid{grid-template-columns:1fr}.ac-shell{padding-top:35px}.ac-progress{grid-template-columns:1fr}.ac-hero h1{font-size:42px}}