:root { --primary: #2563eb; }
    *, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
    body { font-family: system-ui, -apple-system, sans-serif; background: #f4f6f8; color: #1e293b; min-height: 100vh; }
    a { color: inherit; text-decoration: none; }

    header {
      display: flex; align-items: center; justify-content: space-between;
      padding: 12px 20px; background: #fff;
      border-bottom: 1px solid #e2e8f0; box-shadow: 0 1px 3px rgba(0,0,0,.06);
    }
    .logo-wrap { display: inline-flex; align-items: center; gap: 10px; }
    .logo-text { font-size: 1.1rem; font-weight: 700; letter-spacing: .03em; color: var(--primary); }

    /* Index */
    .container { max-width: 1100px; width: 100%; margin: 0 auto; padding: 32px 20px; }
    .section-label { font-size: 1rem; color: #94a3b8; font-weight: 400; margin-bottom: 24px; }
    .empty { color: #94a3b8; font-size: .9rem; }
    .grid { list-style: none; display: grid; gap: 20px; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); }
    .card { background: #fff; border-radius: 10px; overflow: hidden; border: 1px solid #e2e8f0; box-shadow: 0 1px 4px rgba(0,0,0,.06); transition: border-color .2s, box-shadow .2s, transform .15s; }
    .card:hover { border-color: var(--primary); box-shadow: 0 4px 16px rgba(37,99,235,.1); transform: translateY(-2px); }
    .thumb-link { display: block; aspect-ratio: 16/9; overflow: hidden; background: #f1f5f9; }
    .thumb { width: 100%; height: 100%; object-fit: cover; display: block; }
    .thumb-placeholder { display: none; width: 100%; height: 100%; align-items: center; justify-content: center; font-size: 2.5rem; color: #cbd5e1; }
    .card-body { padding: 12px 14px 14px; }
    .card-title { display: block; font-size: .95rem; font-weight: 600; color: #1e293b; margin-bottom: 10px; text-transform: capitalize; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
    .card-actions { display: flex; gap: 8px; }

    /* Buttons */
    .btn { flex: 1; text-align: center; padding: 6px 0; border-radius: 5px; font-size: .78rem; font-weight: 600; cursor: pointer; border: none; }
    .btn-primary { background: var(--primary); color: #fff; }
    .btn-primary:hover { opacity: .88; }
    .btn-secondary { background: #f8fafc; color: #64748b; border: 1px solid #e2e8f0; }
    .btn-secondary:hover { color: #1e293b; border-color: #cbd5e1; background: #f1f5f9; }
    .btn-download { background: #f0fdf4; color: #16a34a; border: 1px solid #bbf7d0; }
    .btn-download:hover { background: #dcfce7; }

    /* Player */
    .player-main { flex: 1; display: flex; flex-direction: column; align-items: center; padding: 24px 16px; }
    .player-title { font-size: clamp(1rem, 2.5vw, 1.5rem); font-weight: 600; margin-bottom: 16px; text-align: center; text-transform: capitalize; }
    .player-wrap { width: 100%; max-width: 960px; }
    .video-js { width: 100%; border-radius: 8px; overflow: hidden; box-shadow: 0 4px 24px rgba(0,0,0,.12); }
    .vjs-big-play-button { border-color: var(--primary) !important; background: rgba(0,0,0,.5) !important; transition: background .2s !important; }
    .vjs-big-play-button:hover { background: var(--primary) !important; }
    .vjs-play-progress, .vjs-volume-level { background: var(--primary) !important; }
    .vjs-play-progress::before { color: var(--primary) !important; }
    .qr-link { font-size: .78rem; padding: 5px 12px; border: 1px solid #e2e8f0; border-radius: 4px; color: #64748b; }
    .qr-link:hover { border-color: var(--primary); color: #1e293b; }
    .back-link { margin-top: 20px; font-size: .85rem; color: #94a3b8; }
    .back-link:hover { color: #475569; }
    .share-btn { margin-top: 20px; gap: 8px; align-items: center; padding: 10px 24px; font-size: .9rem; border-radius: 8px; flex: none; }

    /* QR page */
    .qr-main { flex: 1; display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 32px 16px; gap: 24px; text-align: center; }
    .qr-title { font-size: clamp(1.1rem, 3vw, 1.8rem); font-weight: 700; }
    .qr-card { background: #fff; padding: 20px; border-radius: 12px; border: 1px solid #e2e8f0; box-shadow: 0 4px 16px rgba(0,0,0,.08); }
    .qr-card img { display: block; }
    .url-box { font-size: .78rem; color: #64748b; word-break: break-all; max-width: 340px; padding: 8px 12px; background: #f8fafc; border-radius: 6px; border: 1px solid #e2e8f0; }
    .btn-row { display: flex; gap: 12px; flex-wrap: wrap; justify-content: center; }
    .btn-row .btn { flex: unset; padding: 10px 22px; font-size: .9rem; }

    /* Auth */
    .auth-main { flex: 1; display: flex; align-items: center; justify-content: center; padding: 32px 16px; }
    .auth-card { background: #fff; border: 1px solid #e2e8f0; border-radius: 12px; box-shadow: 0 4px 24px rgba(0,0,0,.08); padding: 36px 32px; width: 100%; max-width: 380px; }
    .auth-title { font-size: 1.4rem; font-weight: 700; margin-bottom: 24px; text-align: center; color: #1e293b; }
    .auth-form { display: flex; flex-direction: column; gap: 12px; }
    .auth-form label { font-size: .85rem; font-weight: 600; color: #475569; }
    .auth-form input { padding: 10px 12px; border: 1px solid #e2e8f0; border-radius: 6px; font-size: .95rem; outline: none; transition: border-color .15s; }
    .auth-form input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px color-mix(in srgb, var(--primary) 15%, transparent); }
    .btn-full { width: 100%; padding: 11px; margin-top: 4px; font-size: .95rem; }
    .auth-error { background: #fef2f2; color: #dc2626; border: 1px solid #fecaca; border-radius: 6px; padding: 10px 12px; font-size: .85rem; margin-bottom: 12px; }
    .auth-msg { text-align: center; color: #15803d; background: #f0fdf4; border: 1px solid #bbf7d0; border-radius: 6px; padding: 14px; font-size: .9rem; line-height: 1.5; }

    @media (max-width: 480px) { header { padding: 8px 12px; } .auth-card { padding: 24px 16px; } }
    @media print {
      header, .btn-row, .back-link { display: none !important; }
      body { background: #fff; }
      .qr-main { justify-content: flex-start; padding-top: 20px; }
      .qr-title { color: #000; }
      .url-box { color: #333; background: #f4f4f4; border-color: #ddd; }
    }