.lessonhero{padding:70px 0 36px}.lessonhero h1{font-size:clamp(36px,5vw,62px);line-height:1.12;max-width:900px;margin:14px 0 16px}.lessonhero p{color:var(--muted);font-size:18px}.lessonhero a{color:var(--cyan)}.lessonlayout{display:grid;grid-template-columns:220px minmax(0,800px);gap:56px;align-items:start;padding-bottom:80px}.lessonaside{position:sticky;top:96px;border:1px solid var(--line);background:var(--panel);border-radius:18px;padding:20px;display:grid;gap:12px;color:var(--muted)}.lessonaside b{color:var(--text)}.lessonaside a{color:var(--cyan)}.progress{height:7px;border-radius:9px;background:#12354d;overflow:hidden}.progress i{display:block;height:100%;background:linear-gradient(90deg,var(--cyan),#5577f2);border-radius:9px}.lessoncontent{display:grid;gap:22px}.lessoncontent>section{border:1px solid var(--line);background:rgba(8,35,55,.76);border-radius:22px;padding:30px}.lessoncontent h2{font-size:28px;margin:0 0 20px}.lessoncontent h3{font-size:20px;margin:24px 0 10px}.lessoncontent p,.lessoncontent li{color:#c9d8e4;line-height:1.85}.lessoncontent li+li{margin-top:7px}.lessoncontent strong{color:#fff}.lessoncontent hr{border:0;border-top:1px solid var(--line);margin:30px 0}.lessoncontent blockquote{margin:20px 0;padding:16px 20px;border-left:3px solid var(--cyan);background:rgba(54,217,232,.07);color:#e8fbff}.lessoncontent code{background:#071c2c;border:1px solid var(--line);border-radius:6px;padding:2px 6px;color:#91f3fb}.tablewrap{overflow:auto}.lessoncontent table{width:100%;border-collapse:collapse;min-width:600px}.lessoncontent th,.lessoncontent td{border:1px solid var(--line);padding:10px;text-align:left;color:#c9d8e4}.lessoncontent th{color:#fff;background:#092a41}.lessonbox,.practice{background:#071f31;border:1px solid var(--line);border-radius:16px;padding:20px;margin:14px 0}.lessonbox h3,.practice h3{margin-top:0}.quiz{border:1px solid var(--line);border-radius:14px;margin:12px 0;background:#071f31}.quiz summary{cursor:pointer;padding:17px 18px;font-weight:700;color:#fff}.quiz ol{padding:0 40px 10px}.answer{border-top:1px solid var(--line);padding:15px 18px;background:rgba(54,217,232,.05)}.lessonnav{display:flex;justify-content:space-between;gap:14px}.lessonnav a{flex:1;border:1px solid var(--line);background:var(--panel);border-radius:14px;padding:16px;color:var(--cyan)}.lessonnav a:last-child{text-align:right}@media(max-width:850px){.lessonlayout{grid-template-columns:1fr;gap:20px}.lessonaside{position:static}.lessoncontent>section{padding:22px}.lessonnav{display:grid}.lessonnav a:last-child{text-align:left}}