:root{color-scheme:light dark;--bg: #f8fafc;--card: #ffffff;--text: #0f172a;--muted: #64748b;--border: #e2e8f0;--accent: #2563eb;--accent-text: #ffffff}@media(prefers-color-scheme:dark){:root{--bg: #0b1120;--card: #111827;--text: #e5e7eb;--muted: #94a3b8;--border: #1f2937;--accent: #3b82f6}}*{box-sizing:border-box}html,body{margin:0;padding:0;min-height:100%}body{background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,Segoe UI,Roboto,Helvetica,Arial,sans-serif;-webkit-font-smoothing:antialiased}.page{max-width:520px;margin:0 auto;padding:24px 20px calc(24px + env(safe-area-inset-bottom));display:flex;flex-direction:column;gap:20px}.card{background:var(--card);border:1px solid var(--border);border-radius:16px;padding:20px;display:flex;flex-direction:column;gap:14px}h1{font-size:1.6rem;margin:0}h2{font-size:1.1rem;margin:0}p{margin:0;color:var(--muted);line-height:1.5}button,.btn{font:inherit;font-weight:600;border:1px solid var(--border);border-radius:12px;padding:14px 18px;background:var(--card);color:var(--text);cursor:pointer;text-decoration:none;text-align:center;display:inline-flex;align-items:center;justify-content:center;gap:8px}button:disabled{opacity:.5;cursor:default}button:active,.btn:active{transform:scale(.99)}.btn-primary{background:var(--accent);color:var(--accent-text);border-color:transparent}.btn-lg{padding:22px 18px;font-size:1.15rem}textarea{width:100%;min-height:84px;border-radius:12px;border:1px solid var(--border);padding:10px;font-family:ui-monospace,SFMono-Regular,Menlo,monospace;font-size:.75rem;background:var(--bg);color:var(--text);resize:vertical}input[type=range]{width:100%}.row{display:flex;align-items:center;gap:10px}.muted{color:var(--muted);font-size:.9rem}.error{color:#ef4444;font-size:.9rem}