:root{color-scheme:dark;--bg:#101419;--surface:#191f26;--border:#343e48;--text:#edf1f4;--muted:#bdc8d2;--accent:#61e4c4;font-family:system-ui,-apple-system,"Segoe UI",sans-serif}
*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--text);font-size:16px;line-height:1.6}main{max-width:1120px;margin:auto;padding:28px 24px 48px}a{color:var(--accent)}a:focus-visible,button:focus-visible,summary:focus-visible{outline:3px solid var(--accent);outline-offset:4px}.back{display:inline-block;padding:8px 0;margin-bottom:32px;text-decoration:none}.brand,.eyebrow{display:block;color:var(--accent);letter-spacing:.13em;font-size:.72rem;font-weight:700}h1{font-size:clamp(2.1rem,6vw,3.9rem);line-height:1.08;letter-spacing:-.045em;margin:12px 0 20px}header>p{max-width:62ch;color:var(--muted);margin-bottom:32px}h2{font-size:1.5rem;line-height:1.25;letter-spacing:-.025em}p{margin-top:0}.watch-layout{display:grid;grid-template-columns:minmax(0,440px) minmax(0,1fr);gap:40px;align-items:start}.player-wrap{border:1px solid var(--border);border-radius:14px;overflow:hidden;background:#080b0e;max-width:440px;margin:auto}video{display:block;width:100%;max-height:78dvh;aspect-ratio:9/16;object-fit:contain}.video-note{color:var(--accent);font-size:.83rem;margin:12px 0 8px}.example-note{color:var(--muted);font-size:.8rem}.chapter-panel{padding:24px;background:var(--surface);border:1px solid var(--border);border-radius:14px}.chapter-panel h2{margin:10px 0}.chapter-panel>p{color:var(--muted)}.chapters{display:grid;gap:8px;margin:24px 0}.chapters button{display:flex;align-items:center;gap:14px;text-align:left;min-height:52px;padding:12px 14px;border:1px solid var(--border);border-radius:9px;background:#11171c;color:var(--text);font:inherit;cursor:pointer}.chapters button span{font-size:.8rem;color:var(--accent);font-variant-numeric:tabular-nums;min-width:34px}.chapters button[aria-current="true"]{border-color:var(--accent);background:#16322d}.start-link{display:inline-block;min-height:44px;padding:10px 0;text-decoration:none;font-weight:700}.quick-guide{margin-top:56px;max-width:820px}.quick-guide h2{margin:10px 0}.intro{color:var(--muted);margin-bottom:24px}.step{border:1px solid var(--border);border-radius:12px;margin:12px 0;background:var(--surface);overflow:hidden}.step summary{padding:16px 18px;min-height:56px;cursor:pointer;font-weight:650}.step summary span{color:var(--accent);padding:0 12px 0 4px;font-size:.8rem}.step>p{padding:0 20px;margin:0 0 20px;color:var(--muted)}.screenshot{display:block;text-align:center;text-decoration:none;padding:0 20px 20px}.screenshot img{display:block;width:100%;max-width:430px;height:auto;max-height:520px;object-fit:contain;background:#0a0e12;border:1px solid var(--border);border-radius:10px;margin:0 auto 12px}.screenshot span{font-size:.85rem}.transcript{margin-top:36px;border-top:1px solid var(--border);padding-top:20px;max-width:820px}.transcript summary{min-height:48px;cursor:pointer}.transcript h3{font-size:1.1rem;margin:24px 0 8px}.transcript p{color:var(--muted)}footer{border-top:1px solid var(--border);margin-top:40px;padding-top:24px;color:var(--muted);font-size:.8rem}#player-status{color:var(--accent);font-size:.85rem}
@media(max-width:700px){main{padding:18px max(16px,env(safe-area-inset-right)) 32px max(16px,env(safe-area-inset-left))}.back{margin-bottom:20px}.watch-layout{grid-template-columns:1fr;gap:20px}.chapter-panel{padding:20px}.chapters{grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}.chapters button{display:grid;gap:3px;padding:10px 12px;font-size:.86rem;min-height:72px}.quick-guide{margin-top:36px}video{max-height:70dvh}.player-wrap{max-width:360px}.screenshot{padding:0 12px 16px}.step summary{font-size:.95rem}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}