/* Scrollbar */
  ::-webkit-scrollbar { width: 8px; height: 8px; }
  ::-webkit-scrollbar-track { background: #0f172a; }
  ::-webkit-scrollbar-thumb { background: #334155; border-radius: 4px; }
  ::-webkit-scrollbar-thumb:hover { background: #475569; }

  /* Tab transitions */
  .tab-content { display: none; animation: fadeIn 0.2s ease-out; }
  .tab-content.active { display: block; }
  @keyframes fadeIn { from { opacity: 0; transform: translateY(4px); } to { opacity: 1; transform: translateY(0); } }

  /* Card hover */
  .book-card { transition: transform 0.15s ease, box-shadow 0.15s ease; }
  .book-card:hover { transform: translateY(-2px); box-shadow: 0 8px 25px rgba(0,0,0,0.3); }

  /* Skeleton shimmer */
  .skeleton { background: linear-gradient(90deg, #1e293b 25%, #334155 50%, #1e293b 75%); background-size: 200% 100%; animation: shimmer 1.5s infinite; }
  @keyframes shimmer { 0% { background-position: 200% 0; } 100% { background-position: -200% 0; } }

  /* Toast animation */
  .toast-enter { animation: toastIn 0.3s ease-out; }
  .toast-exit { animation: toastOut 0.3s ease-in forwards; }
  @keyframes toastIn { from { opacity: 0; transform: translateX(100%); } to { opacity: 1; transform: translateX(0); } }
  @keyframes toastOut { from { opacity: 1; transform: translateX(0); } to { opacity: 0; transform: translateX(100%); } }

  /* Progress bar */
  .progress-bar { transition: width 0.5s ease; }

  /* Active nav indicator */
  .nav-tab.active { border-color: #6366f1; color: #e0e7ff; }
  .sub-tab.active { background: #312e81; color: #c7d2fe; }

  /* Cover placeholder gradients */
  .cover-placeholder { display: flex; align-items: center; justify-content: center; font-size: 2rem; font-weight: 700; color: rgba(255,255,255,0.7); }

  /* Login modal backdrop */
  .modal-backdrop { background: rgba(0,0,0,0.7); backdrop-filter: blur(4px); }

  /* Spin animation for loading */
  .spin { animation: spin 1s linear infinite; }
  @keyframes spin { from { transform: rotate(0deg); } to { transform: rotate(360deg); } }

  /* Download button pulse */
  .dl-active { animation: pulse 2s infinite; }
  @keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.7; } }

  /* Hamburger menu */
  .hamburger-btn { display: none; }
  .mobile-nav-overlay { display: none; }

  /* Mobile responsive */
  @media (max-width: 640px) {
    /* Hamburger menu toggle */
    .hamburger-btn { display: flex; align-items: center; justify-content: center; padding: 0.5rem; }
    #main-nav { display: none; flex-direction: column; position: absolute; top: 100%; left: 0; right: 0; background: #0f172a; border-bottom: 1px solid #1e293b; padding: 0.5rem; z-index: 40; gap: 0; }
    #main-nav.mobile-open { display: flex; }
    #main-nav .nav-tab { border-bottom: none; border-left: 3px solid transparent; padding: 0.75rem 1rem; width: 100%; text-align: left; font-size: 0.95rem; }
    #main-nav .nav-tab.active { border-left-color: #6366f1; border-bottom: none; }

    /* Header adjustments */
    header .max-w-7xl { position: relative; }
    #header-stats { display: none !important; }

    /* Search bar */
    #search-input { font-size: 16px; } /* Prevent iOS zoom on focus */

    /* Results grid — stack vertically */
    #search-results { grid-template-columns: 1fr 1fr !important; gap: 0.5rem; }

    /* Sub-tabs scroll */
    .sub-tab { padding: 0.5rem 0.75rem; font-size: 0.8rem; }

    /* Sort bar */
    #search-sort-bar { flex-direction: column; gap: 0.5rem; }

    /* Larger touch targets for buttons */
    button, a.sub-tab, .nav-tab { min-height: 44px; }

    /* Full width cards on very small screens */
    @media (max-width: 400px) {
      #search-results { grid-template-columns: 1fr !important; }
    }

    /* Library and download list items */
    .book-card { margin-bottom: 0.5rem; }

    /* Main content padding */
    main.flex-1 { padding-left: 0.75rem; padding-right: 0.75rem; }
  }

  @media (max-width: 768px) {
    /* Slightly smaller grid for tablets */
    #search-results { grid-template-columns: repeat(3, 1fr) !important; }
  }

  .librarr-2-body {
    background:
      radial-gradient(circle at top left, rgba(245, 158, 11, 0.10), transparent 28%),
      radial-gradient(circle at top right, rgba(251, 191, 36, 0.08), transparent 24%),
      linear-gradient(180deg, #171311 0%, #12100f 100%);
    color: #e7e0d9;
  }

  .librarr-2-header {
    background: rgba(19, 17, 15, 0.86);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(120, 113, 108, 0.18);
  }

  .librarr-2-shell .nav-tab {
    color: #a8a29e;
    border-bottom-color: transparent;
  }

  .librarr-2-shell .nav-tab:hover {
    color: #f5f5f4;
  }

  .librarr-2-shell .nav-tab.active {
    color: #fff7ed;
    border-bottom-color: #f59e0b;
  }

  .librarr-2-shell .sub-tab.active,
  .librarr-2-shell .lib-tab.active {
    background: rgba(245, 158, 11, 0.18);
    color: #fde68a;
  }

  .home-hero {
    background:
      linear-gradient(135deg, rgba(120, 53, 15, 0.52), rgba(41, 37, 36, 0.92)),
      linear-gradient(180deg, rgba(255,255,255,0.02), rgba(0,0,0,0.12));
    border: 1px solid rgba(245, 158, 11, 0.14);
    box-shadow: 0 20px 50px rgba(0, 0, 0, 0.28);
  }

  .dashboard-panel {
    box-shadow: 0 16px 44px rgba(0, 0, 0, 0.18);
  }

  .shelf-card {
    transition: transform 0.18s ease, box-shadow 0.18s ease, border-color 0.18s ease;
  }

  .shelf-card:hover {
    transform: translateY(-4px);
    border-color: rgba(245, 158, 11, 0.28);
    box-shadow: 0 22px 55px rgba(0, 0, 0, 0.26);
  }

  .shelf-card .cover-placeholder {
    font-size: 2.6rem;
    letter-spacing: -0.04em;
  }

  #library-search,
  #search-input {
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.02);
  }

  #book-detail-modal .cover-placeholder {
    font-size: 4rem;
  }

  @media (max-width: 640px) {
    .home-hero {
      border-radius: 1.5rem;
    }

    .shelf-card {
      border-radius: 1.5rem;
    }

    #main-nav.mobile-open {
      background: #171311;
      border-bottom-color: rgba(120, 113, 108, 0.18);
    }

    .librarr-2-shell .nav-tab.active {
      border-left-color: #f59e0b !important;
    }
  }