:root{--bg: #080A0F;--bg-soft: #0D1118;--panel: #11141C;--card: #151A24;--text: #F4F1EA;--muted: #A8AFBD;--quiet: #6E7687;--blue: #7DD3FC;--violet: #A78BFA;--amber: #F8C471;--line: rgba(255,255,255,.1);--line-strong: rgba(255,255,255,.18)}*{box-sizing:border-box}html{background:var(--bg);color:var(--text);font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}body{margin:0;min-height:100vh;background:radial-gradient(circle at 20% 8%,rgba(125,211,252,.16),transparent 28rem),radial-gradient(circle at 80% 18%,rgba(167,139,250,.13),transparent 30rem),radial-gradient(circle at 55% 100%,rgba(248,196,113,.06),transparent 26rem),var(--bg);color:var(--text)}a{color:inherit;text-decoration:none}p{color:var(--muted);line-height:1.7}h1,h2,h3{color:var(--text)}.container{width:min(1120px,calc(100% - 40px));margin-inline:auto}.site-header{position:sticky;top:0;z-index:10;display:flex;align-items:center;justify-content:space-between;padding:22px 40px;border-bottom:1px solid var(--line);background:#080a0fb8;backdrop-filter:blur(18px)}.logo{font-weight:850;letter-spacing:-.045em}.logo span{color:var(--blue)}nav{display:flex;gap:24px}nav a{color:var(--muted);font-size:.95rem}nav a:hover{color:var(--text)}.grid-bg{background-image:linear-gradient(rgba(255,255,255,.045) 1px,transparent 1px),linear-gradient(90deg,rgba(255,255,255,.045) 1px,transparent 1px);background-size:48px 48px}.hero{padding:120px 0 96px}.label{margin:0 0 20px;color:var(--blue);font-size:.76rem;font-weight:800;letter-spacing:.16em;text-transform:uppercase}.hero h1{max-width:920px;margin:0;font-size:clamp(3.4rem,8vw,7.5rem);line-height:.92;letter-spacing:-.075em}.hero-copy{max-width:720px;margin-top:28px;font-size:clamp(1.1rem,2vw,1.35rem)}.button-row{display:flex;flex-wrap:wrap;gap:14px;margin-top:34px}.button{display:inline-flex;align-items:center;justify-content:center;min-height:46px;padding:0 18px;border-radius:999px;border:1px solid var(--line-strong);color:var(--text);background:#ffffff0b}.button:hover{border-color:#ffffff52;background:#ffffff13}.button.primary{border-color:#7dd3fc73;background:#7dd3fc1f;box-shadow:0 0 48px #7dd3fc1f}.section{padding:84px 0}.section h1,.section h2{max-width:860px;margin:0 0 20px;font-size:clamp(2.4rem,5vw,5rem);line-height:.95;letter-spacing:-.06em}.section-copy{max-width:740px;font-size:1.08rem}.topic-grid,.lesson-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;margin-top:38px}.card{border:1px solid var(--line);border-radius:24px;background:linear-gradient(180deg,#ffffff0e,#ffffff05);padding:28px}.card h3{margin:0 0 14px;font-size:1.35rem;line-height:1.15;letter-spacing:-.035em}.card p:last-child{margin-bottom:0}.lesson-card{display:block;transition:transform .16s ease,border-color .16s ease,background .16s ease}.lesson-card:hover{transform:translateY(-3px);border-color:#7dd3fc5c;background:linear-gradient(180deg,#7dd3fc17,#ffffff05)}.feature-card{overflow:hidden;position:relative}.feature-card:after{content:"";position:absolute;width:280px;height:280px;right:-80px;top:-80px;border-radius:999px;background:#7dd3fc1a;filter:blur(6px)}.lesson-shell{padding:72px 0 96px}.lesson-article{width:min(820px,calc(100% - 40px));margin-inline:auto}.back-link{display:inline-flex;margin-bottom:36px;color:var(--muted)}.back-link:hover{color:var(--text)}.lesson-article h1{margin:0;font-size:clamp(3rem,7vw,6.5rem);line-height:.92;letter-spacing:-.075em}.lesson-description{margin-top:24px;font-size:1.25rem}.lesson-content{margin-top:56px}.lesson-content h2{margin-top:56px;margin-bottom:12px;font-size:clamp(1.8rem,3vw,2.6rem);line-height:1;letter-spacing:-.045em}.lesson-content h3{margin-top:36px;margin-bottom:10px;font-size:1.35rem}.lesson-content p,.lesson-content li{color:var(--muted);font-size:1.06rem;line-height:1.8}.lesson-content strong{color:var(--text)}.lesson-content blockquote{margin:32px 0;padding:22px 26px;border-left:3px solid var(--blue);border-radius:18px;background:#7dd3fc14}.lesson-content blockquote p{margin:0;color:var(--text)}.site-footer{border-top:1px solid var(--line);padding:28px 0}.footer-inner{display:flex;justify-content:space-between;gap:20px}.site-footer p{margin:0;color:var(--quiet);font-size:.95rem}.footer-links{display:flex;gap:18px}.footer-links a:hover{color:var(--text)}@media(max-width:800px){.site-header{padding:18px 20px}nav{gap:14px}.hero{padding:88px 0 72px}.topic-grid,.lesson-grid{grid-template-columns:1fr}.footer-inner{flex-direction:column}}