:root{--bg:#0b0d10;--bg-elev:#14181d;--bg-elev-2:#1b2027;--border:#262c34;--text:#eef1f4;--text-dim:#97a1ad;--accent:#22c55e;--accent-dim:#16a34a;--radius:14px}*{box-sizing:border-box}body,html{margin:0;padding:0;background:var(--bg);color:var(--text);font-family:ui-sans-serif,system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}.topbar{position:-webkit-sticky;position:sticky;top:0;z-index:20;justify-content:space-between;gap:16px;padding:14px 28px;background:rgba(11,13,16,.82);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);border-bottom:1px solid var(--border)}.brand,.topbar{display:flex;align-items:center}.brand{gap:12px;font-weight:700;letter-spacing:.02em}.brand .logo{width:30px;height:30px;border-radius:8px;background:linear-gradient(135deg,var(--accent),#4ade80);display:grid;place-items:center;color:#052e16;font-weight:900}.brand small{display:block;font-weight:500;font-size:11px;color:var(--text-dim);letter-spacing:.06em;text-transform:uppercase}.logout-btn{background:transparent;border:1px solid var(--border);color:var(--text-dim);padding:7px 14px;border-radius:999px;font-size:13px;cursor:pointer;transition:all .15s}.logout-btn:hover{color:var(--text);border-color:#3a424c}.container{max-width:1180px;margin:0 auto;padding:32px 28px 80px}.hero{padding:26px 0 10px}.hero h1{font-size:clamp(26px,4vw,40px);margin:0 0 8px;letter-spacing:-.02em}.hero p{color:var(--text-dim);margin:0;font-size:15px}.section-title{font-size:13px;text-transform:uppercase;letter-spacing:.12em;color:var(--text-dim);margin:40px 0 16px;display:flex;align-items:center;gap:10px}.section-title:after{content:"";flex:1 1;height:1px;background:var(--border)}.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));grid-gap:18px;gap:18px}.card{position:relative;display:flex;flex-direction:column;background:var(--bg-elev);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;transition:transform .16s,border-color .16s,background .16s}.card:hover{transform:translateY(-3px);border-color:#3a424c;background:var(--bg-elev-2)}.card .thumb{aspect-ratio:16/9;background:linear-gradient(135deg,#191f27,#232b35);display:grid;place-items:center;position:relative;overflow:hidden}.card .thumb-img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}.card .thumb:after{content:"";position:absolute;inset:0;background:linear-gradient(180deg,rgba(0,0,0,.25),rgba(0,0,0,.15))}.card .thumb-img{transition:transform .35s ease}.card:hover .thumb-img{transform:scale(1.05)}.card .thumb .badge,.card .thumb .play{position:relative;z-index:2}.card .thumb .play{width:46px;height:46px;border-radius:999px;background:rgba(34,197,94,.22);border:1px solid rgba(34,197,94,.6);-webkit-backdrop-filter:blur(2px);backdrop-filter:blur(2px);display:grid;place-items:center;color:#fff;opacity:0;transform:scale(.9);transition:opacity .18s ease,transform .18s ease}.card:hover .thumb .play{opacity:1;transform:scale(1)}.card .thumb .badge{position:absolute;top:10px;left:10px;font-size:11px;padding:3px 9px;border-radius:999px;background:rgba(0,0,0,.45);color:var(--text-dim);border:1px solid var(--border)}.card .body{padding:14px 16px 16px}.card .body h3{margin:0 0 6px;font-size:16px;letter-spacing:-.01em}.card .meta{color:var(--text-dim);font-size:13px;display:flex;gap:8px;align-items:center}.dot{width:3px;height:3px;border-radius:999px;background:currentColor;opacity:.6}.back-btn{display:inline-flex;align-items:center;gap:7px;padding:8px 15px 8px 12px;border:1px solid var(--border);border-radius:999px;background:var(--bg-elev);color:var(--text-dim);font-size:13px;margin-bottom:16px;transition:color .15s,border-color .15s,background .15s}.back-btn:hover{color:var(--text);border-color:#3a424c;background:var(--bg-elev-2)}.crumb{display:flex;align-items:center;gap:8px;font-size:13px;color:var(--text-dim);margin-bottom:18px}.crumb a:hover{color:var(--text)}.lesson-list{display:flex;flex-direction:column;gap:8px}.lesson{display:flex;align-items:center;gap:16px;padding:13px 16px;background:var(--bg-elev);border:1px solid var(--border);border-radius:12px;transition:background .14s,border-color .14s}.lesson:hover{background:var(--bg-elev-2);border-color:#3a424c}.lesson.active{border-color:var(--accent);background:rgba(34,197,94,.08)}.lesson .num{flex:none;width:30px;height:30px;border-radius:8px;background:var(--bg-elev-2);display:grid;place-items:center;font-size:13px;color:var(--text-dim);font-feature-settings:"tnum";font-variant-numeric:tabular-nums}.lesson-thumb{flex:none;width:84px;height:47px;border-radius:8px;object-fit:cover;background:var(--bg-elev-2)}.lesson .info{flex:1 1;min-width:0}.lesson .info .t{font-size:15px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.lesson .info .s{font-size:12px}.lesson .chev,.lesson .info .s{color:var(--text-dim)}.lesson .watched{color:var(--accent);font-size:12px}.progress{height:3px;border-radius:999px;background:var(--border);overflow:hidden;margin-top:6px}.progress>span{display:block;height:100%;background:var(--accent)}.watch-layout{display:grid;grid-template-columns:minmax(0,1fr) 340px;grid-gap:24px;gap:24px;align-items:start}@media (max-width:900px){.watch-layout{grid-template-columns:1fr}}.player-wrap{background:#000;border-radius:var(--radius);overflow:hidden;border:1px solid var(--border)}.player-wrap video{width:100%;display:block;aspect-ratio:16/9;background:#000}.watch-title{font-size:22px;margin:18px 0 4px;letter-spacing:-.01em}.watch-sub{color:var(--text-dim);font-size:14px}.nav-row{display:flex;justify-content:space-between;gap:12px;margin-top:20px}.nav-btn{flex:1 1;padding:12px 16px;border:1px solid var(--border);border-radius:12px;background:var(--bg-elev);color:var(--text);font-size:14px;transition:background .14s,border-color .14s}.nav-btn:hover{background:var(--bg-elev-2);border-color:#3a424c}.nav-btn.disabled{opacity:.35;pointer-events:none}.nav-btn small{display:block;color:var(--text-dim);font-size:11px;text-transform:uppercase;letter-spacing:.08em;margin-bottom:3px}.playlist{background:var(--bg-elev);border:1px solid var(--border);border-radius:var(--radius);overflow:hidden;max-height:78vh;display:flex;flex-direction:column}.playlist .head{padding:14px 16px;border-bottom:1px solid var(--border);font-size:13px;color:var(--text-dim);text-transform:uppercase;letter-spacing:.08em}.playlist .scroll{overflow-y:auto}.pl-item{display:flex;gap:12px;padding:11px 16px;border-bottom:1px solid var(--border);align-items:center}.pl-item:hover{background:var(--bg-elev-2)}.pl-item.active{background:rgba(34,197,94,.1)}.pl-item .n{color:var(--text-dim);font-size:12px;width:20px;text-align:right;font-feature-settings:"tnum";font-variant-numeric:tabular-nums}.pl-item .tt{font-size:13.5px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.login-screen{min-height:100vh;display:grid;place-items:center;padding:24px}.login-card{width:100%;max-width:380px;background:var(--bg-elev);border:1px solid var(--border);border-radius:18px;padding:32px 28px;text-align:center}.login-card .logo{width:48px;height:48px;border-radius:12px;margin:0 auto 16px;background:linear-gradient(135deg,var(--accent),#4ade80);display:grid;place-items:center;color:#052e16;font-weight:900;font-size:20px}.login-card h1{font-size:20px;margin:0 0 4px}.login-card p{color:var(--text-dim);font-size:14px;margin:0 0 22px}.login-card input{width:100%;padding:12px 14px;border-radius:10px;border:1px solid var(--border);background:var(--bg);color:var(--text);font-size:15px;margin-bottom:12px}.login-card input:focus{outline:none;border-color:var(--accent)}.login-card button{width:100%;padding:12px 14px;border-radius:10px;border:none;background:var(--accent);color:#052e16;font-weight:700;font-size:15px;cursor:pointer}.login-card button:hover{background:var(--accent-dim)}.login-error{color:#ff7a7a;font-size:13px;margin-bottom:12px}.empty{color:var(--text-dim);padding:40px 0;text-align:center}