:root{--lightningcss-light:initial;--lightningcss-dark: ;color-scheme:light;--color-primary:#3b82f6;--color-primary-dark:#2563eb;--color-primary-50:#eff6ff;--color-success:#10b981;--color-danger:#ef4444;--color-slate-50:#f8fafc;--color-slate-100:#f1f5f9;--color-slate-200:#e2e8f0;--color-slate-300:#cbd5e1;--color-slate-500:#64748b;--color-slate-600:#475569;--color-slate-700:#334155;--color-slate-900:#0f172a;--background:#f8fafc;--surface:#fff;--border:#e2e8f0;--on-background:#0f172a;--on-surface:#334155;--on-surface-muted:#64748b;--space-1:4px;--space-2:8px;--space-3:16px;--space-4:24px;--space-5:32px;--space-6:48px;--radius-md:8px;--radius-lg:12px;--radius-xl:16px;--font-display:var(--font-display-loaded), "Fira Sans", "Noto Sans TC", system-ui, sans-serif;--font-body:var(--font-body-loaded), "Noto Sans TC", system-ui, -apple-system, sans-serif;--ease-out:cubic-bezier(.16, 1, .3, 1)}*{box-sizing:border-box}html,body{min-height:100%;margin:0}body{background:radial-gradient(1200px 600px at 10% -10%, #3b82f624, transparent 55%), radial-gradient(900px 500px at 90% 0%, #10b9811a, transparent 50%), var(--background);color:var(--on-background);font-family:var(--font-body);line-height:1.5}a{color:var(--color-primary-dark);text-underline-offset:3px;text-decoration-thickness:1px}main{width:min(720px,100% - 32px);padding:var(--space-5) 0 var(--space-6);margin:0 auto}main.wide{width:min(960px,100% - 32px)}.nav{justify-content:space-between;align-items:center;gap:var(--space-3);margin-bottom:var(--space-5);display:flex}.nav-brand{font-family:var(--font-display);letter-spacing:-.02em;color:var(--on-background);font-size:1.25rem;font-weight:700;text-decoration:none}.nav-links{justify-content:flex-end;align-items:center;gap:var(--space-3);flex-wrap:wrap;font-size:.9375rem;display:flex}.nav-links a{color:var(--on-surface);text-decoration:none}.nav-links a:hover{color:var(--color-primary-dark)}.nav-email{color:var(--on-surface-muted);text-overflow:ellipsis;white-space:nowrap;max-width:160px;font-size:.8125rem;overflow:hidden}.hero{padding:var(--space-6) 0 var(--space-5);justify-content:center;gap:var(--space-4);flex-direction:column;min-height:min(70vh,640px);display:flex}.hero-brand{font-family:var(--font-display);letter-spacing:-.04em;margin:0;font-size:clamp(2.75rem,8vw,4.5rem);font-weight:700;line-height:1.05}.hero h1{font-family:var(--font-display);letter-spacing:-.02em;color:var(--on-surface);max-width:28ch;margin:0;font-size:clamp(1.35rem,3.5vw,1.85rem);font-weight:600;line-height:1.3}.hero-lead{color:var(--on-surface-muted);max-width:36ch;margin:0;font-size:1.05rem}.panel{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-xl);padding:var(--space-4)}.panel h1,.panel h2{font-family:var(--font-display);letter-spacing:-.02em;margin-top:0}.panel h1{font-size:clamp(1.5rem,3vw,2rem)}.panel h2{font-size:1.2rem}.muted{color:var(--on-surface-muted)}.actions{gap:var(--space-2);margin-top:var(--space-3);flex-wrap:wrap;display:flex}.button{border:1px solid var(--color-primary);border-radius:var(--radius-md);background:var(--color-primary);color:#fff;font:inherit;cursor:pointer;transition:background .18s var(--ease-out), border-color .18s var(--ease-out), transform .18s var(--ease-out);justify-content:center;align-items:center;padding:11px 18px;font-weight:600;text-decoration:none;display:inline-flex}.button:hover{background:var(--color-primary-dark);border-color:var(--color-primary-dark)}.button:active{transform:translateY(1px)}.button.secondary{color:var(--color-primary-dark);background:0 0}.button:disabled{opacity:.55;cursor:not-allowed}.form{gap:14px;max-width:420px;display:grid}.form label{color:var(--on-surface);gap:6px;font-weight:600;display:grid}.form input,.form textarea{border:1px solid var(--border);border-radius:var(--radius-md);font:inherit;background:var(--surface);color:var(--on-background);padding:11px 12px}.form input:focus,.form textarea:focus,.button:focus-visible{outline:2px solid var(--color-primary);outline-offset:2px}.error{color:var(--color-danger)}.provider-actions{flex-wrap:wrap;gap:10px;margin-top:20px;display:flex}.lesson-list{margin:var(--space-4) 0 0;gap:var(--space-2);padding:0;list-style:none;display:grid}.lesson-list a{border:1px solid var(--border);border-radius:var(--radius-lg);color:var(--on-background);background:var(--color-slate-50);transition:border-color .16s var(--ease-out), background .16s var(--ease-out);padding:14px 16px;text-decoration:none;display:block}.lesson-list a:hover{border-color:var(--color-primary);background:var(--color-primary-50)}.site-footer{margin:var(--space-6) auto 0;max-width:720px;padding:var(--space-4) 20px 40px;border-top:1px solid var(--border);font-size:.875rem}.lesson-player{border-radius:var(--radius-lg);aspect-ratio:16/9;background:#000;border:0;width:100%;margin-top:20px}.stack{gap:var(--space-4);display:grid}.callout{padding:var(--space-3);border-radius:var(--radius-lg);background:var(--color-primary-50);color:var(--on-surface);border:1px solid #3b82f640}@media (max-width:640px){.nav{flex-direction:column;align-items:flex-start}.nav-links{justify-content:flex-start}.hero{min-height:auto;padding-top:var(--space-4)}}