:root{
  --bg:#081019;--panel:#101b27;--panel2:#132131;--border:#23374c;
  --text:#eef6ff;--muted:#91a3b6;--accent:#53d3ff;--accent2:#9177ff;
  --green:#74e5a1;--yellow:#ffd166;--red:#ff7b86
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;font-family:Inter,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;background:radial-gradient(circle at top left,rgba(83,211,255,.08),transparent 28%),radial-gradient(circle at top right,rgba(145,119,255,.07),transparent 28%),var(--bg);color:var(--text)}
a{color:var(--accent)}
.wrap{width:min(1050px,calc(100% - 32px));margin:auto;padding-bottom:60px}
nav{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:25px 0}
.brand{display:flex;align-items:center;gap:12px;color:var(--text);text-decoration:none;font-weight:800}
.mark{width:42px;height:42px;display:grid;place-items:center;border-radius:11px;background:linear-gradient(135deg,var(--accent),var(--accent2));color:#061018;font-size:.72rem;font-weight:900;letter-spacing:.04em}
.brand-sub{margin-top:3px;color:var(--muted);font-size:.68rem;letter-spacing:.1em;text-transform:uppercase}
.back{color:var(--muted);text-decoration:none;font-size:.9rem}.back:hover{color:var(--text)}
.hero{max-width:880px;padding:65px 0 48px}.eyebrow{color:var(--accent);text-transform:uppercase;letter-spacing:.15em;font-size:.74rem;font-weight:800}
h1{margin:12px 0 20px;font-size:clamp(3.1rem,7vw,5.8rem);line-height:.95;letter-spacing:-.045em}
h2{margin-top:0;font-size:1.8rem}h3{margin-top:0}.gradient{background:linear-gradient(90deg,var(--accent),#c2efff,var(--accent2));-webkit-background-clip:text;background-clip:text;color:transparent}
.hero p,p,li{color:var(--muted);line-height:1.7}.hero p{font-size:1.03rem}.meta{display:flex;flex-wrap:wrap;gap:9px;margin-top:25px}.pill{padding:7px 11px;border:1px solid var(--border);border-radius:999px;background:var(--panel);color:var(--muted);font-size:.76rem}
section{margin:55px 0}.panel,.card,.quiz{padding:26px;border:1px solid var(--border);border-radius:16px;background:var(--panel);margin:18px 0}.grid2,.grid3{display:grid;gap:15px}.grid2{grid-template-columns:repeat(2,1fr)}.grid3{grid-template-columns:repeat(3,1fr)}.card{margin:0;padding:22px}.card p:last-child{margin-bottom:0}.number{color:var(--accent);font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.72rem;margin-bottom:13px}strong{color:var(--text)}
.note{padding:18px 20px;border-left:3px solid var(--accent);background:rgba(83,211,255,.06);border-radius:0 10px 10px 0;margin:22px 0;color:var(--muted);line-height:1.7}.warning{border-left-color:var(--yellow);background:rgba(255,209,102,.06)}.exam{border-left-color:var(--accent2);background:rgba(145,119,255,.07)}
.diagram{overflow-x:auto;margin:25px 0;padding:28px 20px;border:1px solid var(--border);border-radius:14px;background:#09131e}.flow{min-width:620px;display:flex;justify-content:center;align-items:center;gap:12px}.device{min-width:135px;padding:17px 14px;border:1px solid var(--green);border-radius:10px;background:rgba(116,229,161,.05);text-align:center}.device.accent{border-color:var(--accent);background:rgba(83,211,255,.05)}.device.purple{border-color:var(--accent2);background:rgba(145,119,255,.06)}.device small{display:block;margin-top:5px;color:var(--muted)}.link{min-width:70px;height:2px;background:var(--border);position:relative}.link span{position:absolute;width:120px;left:-25px;top:-28px;text-align:center;color:var(--accent);font-size:.68rem}
code{font-family:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace}p code,li code,td code{color:#ccecff;background:#09131e;border:1px solid var(--border);border-radius:5px;padding:.1em .35em}pre{overflow:auto;padding:20px;border:1px solid var(--border);border-radius:12px;background:#050b11;color:#ccecff;line-height:1.65;font-size:.86rem}.cmd{color:var(--green)}.comment{color:#71869a}
.table-wrap{overflow-x:auto}table{width:100%;border-collapse:collapse;margin-top:18px}th,td{padding:13px;border-bottom:1px solid var(--border);text-align:left}th{color:var(--text);font-size:.82rem}td{color:var(--muted);font-size:.86rem}
.quiz{margin:0}.question{margin:30px 0;padding-bottom:25px;border-bottom:1px solid var(--border)}.question:last-of-type{border-bottom:0}.question h3{font-size:1rem;line-height:1.5}.answer{display:block;width:100%;margin:8px 0;padding:12px 14px;text-align:left;color:var(--muted);background:#0b1520;border:1px solid var(--border);border-radius:9px;cursor:pointer;font:inherit}.answer:hover,.answer:focus-visible{border-color:var(--accent);color:var(--text);outline:0}.answer.correct{border-color:var(--green);color:var(--green)}.answer.wrong{border-color:var(--red);color:var(--red)}.feedback{min-height:20px;margin-top:10px;color:var(--muted);font-size:.84rem}.score{margin-top:20px;padding:17px;text-align:center;border:1px solid var(--border);border-radius:10px;color:var(--accent)}
.next{display:block;padding:28px;border:1px solid var(--border);border-radius:16px;background:linear-gradient(135deg,rgba(83,211,255,.07),rgba(145,119,255,.07));color:var(--text);text-decoration:none}.next:hover{border-color:var(--accent)}.next span{color:var(--accent);font-size:.75rem;text-transform:uppercase;letter-spacing:.12em}.next h2{margin:9px 0 7px}.next p{margin:0}
.lesson-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:15px;margin:28px 0 60px}.lesson-card{position:relative;min-height:210px;padding:23px;border:1px solid var(--border);border-radius:15px;background:var(--panel);color:var(--text);text-decoration:none;transition:.18s ease}.lesson-card:hover{transform:translateY(-2px);border-color:rgba(83,211,255,.45);background:var(--panel2)}.lesson-card .number{margin-bottom:28px}.lesson-card h2{font-size:1.25rem;margin:0 0 9px}.lesson-card p{font-size:.88rem;margin:0}.topic-list{display:flex;flex-wrap:wrap;gap:7px;margin-top:18px}.topic-list span{font-size:.69rem;color:var(--muted);padding:5px 8px;border:1px solid var(--border);border-radius:999px}
.overview{display:grid;grid-template-columns:2fr 1fr;gap:18px;margin:20px 0 55px}.stat{font-size:2.4rem;font-weight:850;letter-spacing:-.04em;color:var(--accent)}
footer{display:flex;justify-content:space-between;flex-wrap:wrap;gap:15px;margin-top:60px;padding-top:20px;border-top:1px solid var(--border);color:var(--muted);font-size:.78rem}
@media(max-width:760px){.grid2,.grid3,.lesson-grid,.overview{grid-template-columns:1fr}.hero{padding-top:45px}nav{align-items:flex-start}.back{max-width:42%;text-align:right}.flow{justify-content:flex-start}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}.lesson-card{transition:none}}