body {
      margin: 0;
      font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      display: flex;
      height: 100vh;
      background: #1e1e2f;
      color: #ddd;
    }

    /* --- Sidebar --- */
    #sidebar {
      width: 350px;
      background: #2c2c3c;
      display: flex;
      flex-direction: column;
      border-right: 1px solid #444;
      overflow: hidden;
    }

    #doc-selector-container {
      padding: 10px;
      border-bottom: 1px solid #444;
    }

    #doc-selector {
      width: 100%;
      padding: 6px;
      border-radius: 6px;
      border: none;
      background: #1e1e2f;
      color: #ddd;
    }

    #search-container {
      padding: 10px;
      border-bottom: 1px solid #444;
      display: flex;
      gap: 10px;
      align-items: center;
    }

    #search {
      flex: 1;
      padding: 8px 10px;
      border-radius: 6px;
      border: none;
      background: #1e1e2f;
      color: #ddd;
      font-size: 0.95em;
    }

    #reset-btn {
      padding: 6px 10px;
      border: none;
      border-radius: 6px;
      background-color: #4a4a6a;
      color: #ddd;
      cursor: pointer;
      font-size: 0.85em;
      transition: background 0.3s;
    }
    #reset-btn:hover {
      background-color: #5a5a80;
    }

    #tree-container {
      flex: 1;
      overflow-y: auto;
      padding: 10px;
    }

    #results-container {
      display: none;
      border-top: 1px solid #444;
      overflow-y: auto;
      max-height: 50%;
      padding: 10px;
      background-color: #2c2c3c;
      transition: opacity 0.3s ease;
    }

    h3 {
      margin: 10px 0 5px 0;
      font-size: 0.9em;
      color: #aaa;
    }

    ul { list-style: none; padding-left: 20px; margin: 0; }
    li { margin: 5px 0; cursor: pointer; user-select: none; line-height: 1.4; padding-left: 6px; transition: background 0.2s, padding-left 0.2s; }
    li.folder::before { content: "▶ "; display: inline-block; width: 20px; color: #999; }
    li.folder.open::before { content: "▼ "; color: #bbb; }
    li.doc::before { content: "📄 "; display: inline-block; width: 20px; }
    li:hover { background-color: #3a3a4a; border-radius: 4px; padding-left: 6px; }
    li.folder:not(.active):hover {padding-left: 12px; background-color: #3a3a4a; border-radius: 4px; }
    li.folder.active { padding-left: 12px; background-color: #3a3a4a; border-radius: 4px; transition: background 0.2s, padding-left 0.2s; }
  /* ... existing styles ... */

  li.doc {
      /* We let JS handle the specific padding-left calculation */
      transition: background-color 0.2s, border-color 0.2s;
      border-left: 3px solid transparent; /* Invisible border by default */
      border-radius: 0 4px 4px 0; /* Rounded corners only on the right */
      margin-bottom: 2px;
  }

  li.doc:not(.selected):hover {
      /* Just change the background color (shade it) */
      background-color: #3a3a4a;
      border-left-color: #666; /* Subtle grey accent on hover */
  }

  li.doc.selected {
      background-color: #505070;
      border-left-color: #64b5f6; /* Blue accent for selected file */
  }

  /* ... existing styles ... */

    #viewer {
      flex: 1;
      display: flex;
      flex-direction: column;
      padding: 10px;
      overflow: hidden;
    }
    #viewer h2 { margin: 0 0 10px 0; font-size: 1.2em; color: #fff; }
    #viewer iframe { flex: 1; border: none; border-radius: 4px; background: #fff; }
    #results-list li { padding: 5px; border-bottom: 1px solid #444; border-radius: 4px; transition: background 0.2s; }
    #results-list li:hover { background-color: #505070; }
    mark { background-color: rgba(255, 255, 0, 0.3); color: #fff; padding: 0 2px; border-radius: 2px; }
    /* ===== iOS SAFARI FIX (ADD THIS AT THE VERY END) ===== */

  html, body {
    height: 100%;
  }

  body {
    min-height: 100dvh;
    min-height: -webkit-fill-available;
  }

  #sidebar {
    min-height: 0;
  }

  #tree-container {
    min-height: 0;
    -webkit-overflow-scrolling: touch;
  }

  #viewer {
    position: relative;
  }

  #pdf-overlay {
    position: absolute;
    inset: 40px 10px 10px 10px; /* below title, inside padding */
    display: flex;
    align-items: center;
    justify-content: center;
    background: #1e1e2f;
    z-index: 5;
    pointer-events: none;
    transition: opacity 0.25s ease;
  }

  #pdf-overlay.hidden {
    opacity: 0;
  }

  @keyframes spin {
    to { transform: rotate(360deg); }
  }




  /* Hide mobile top bar by default (desktop) */
  #top-bar {
    display: none;
  }





  /* Mobile PWA layout */
  body.mobile {
    flex-direction: column; /* sidebar on top, viewer below */
  }

  body.mobile #sidebar {
    width: 100%;
    height: 200px;         /* smaller sidebar height */
    flex: none;            /* don't stretch */
    overflow-x: auto;      /* scroll horizontally if needed */
    border-right: none;
    border-bottom: 1px solid #444;
  }

  body.mobile #doc-selector-container,
  body.mobile #search-container {
    padding: 8px 10px;
  }

  body.mobile #tree-container {
    flex: 1;
    max-height: 120px; /* small scrollable area */
    overflow-y: auto;
  }

  body.mobile #viewer {
    flex: 1;
    height: calc(100vh - 48px); /* exact height of top bar */
    padding: 5px;
    overflow: hidden;
  }


  /* Touch-friendly list items */
  body.mobile li {
    padding: 12px 10px !important;
    font-size: 1em;
  }

  body.mobile li.doc.selected {
    border-left-color: #64b5f6;
    background-color: #505070;
  }


  /* Mobile: make PDF viewer fill available space and remove rounded corners */
  body.mobile #viewer iframe {
    height: 100%;
    width: 100%;
    border-radius: 0;
  }


  /* ======================= Mobile Optimized Layout ======================= */
  body.mobile {
    flex-direction: column; /* sidebar on top, viewer below */
    height: 100vh;
    overflow: hidden;       /* prevent double scrollbars */
  }

  /* Sidebar styling */
  body.mobile #sidebar {
    width: 100%;
    height: 180px;          /* smaller, fixed height */
    flex: none;
    overflow-y: auto;
    overflow-x: hidden;
    border-right: none;
    border-bottom: 1px solid #444;
    display: none;           /* hidden by default, toggled via JS */
    z-index: 99;
  }

  /* Sidebar containers */
  body.mobile #doc-selector-container,
  body.mobile #search-container {
    padding: 8px 10px;
    font-size: 0.95em;
  }

  /* Tree container scrollable */
  body.mobile #tree-container {
    max-height: 100px;
    overflow-y: auto;
    padding: 5px 10px;
  }

  /* Search results */
  body.mobile #results-container {
    max-height: 80px;
    overflow-y: auto;
    padding: 5px 10px;
  }

  /* Touch-friendly list items */
  body.mobile li {
    padding: 12px 10px !important;
    font-size: 1em;
  }

  /* Folder toggles bigger for touch */
  body.mobile li.folder::before {
    width: 24px;
  }

  /* Viewer styling */
  body.mobile #viewer {
    flex: 1;
    height: calc(100vh - 180px); /* remaining height under sidebar */
    padding: 5px;
    overflow: hidden;
  }

  /* Viewer iframe full size */
  body.mobile #viewer iframe {
    width: 100%;
    height: 100%;
    border-radius: 0;
  }

  /* PDF overlay remains centered */
  body.mobile #pdf-overlay {
    inset: 40px 10px 10px 10px;
  }

  /* Floating toggle button */
  body.mobile button#mobile-toggle-btn {
    position: fixed;
    top: 5px;
    left: 5px;
    z-index: 100;
    padding: 6px 10px;
    border-radius: 4px;
    background: #2c2c3c;
    color: #ddd;
    border: none;
    font-size: 1.2em;
    cursor: pointer;
  }

  /* Optional: smoother scrolling */
  body.mobile #tree-container,
  body.mobile #results-container,
  body.mobile #sidebar {
    -webkit-overflow-scrolling: touch;
  }
    
  body.mobile #results-container {
    max-height: 150px;  /* bigger for touch */
    width: 100%;
    overflow-y: auto;
    padding: 5px 10px;
  }


  /* Mobile full-screen sidebar menu */
  body.mobile #sidebar {
    position: fixed;
    top: 30px;
    left: 0;
    width: 100%;
    height: 100%;
    background: #2c2c3c;
    z-index: 200;
    flex-direction: column;
    display: none;          /* hidden by default */
    overflow-y: auto;
    padding: 20px 10px;
    transition: transform 0.3s ease;
  }

  /* When menu is open */
  body.mobile #sidebar.open {
    display: flex;
    transform: translateX(0);
  }

  /* Hide sidebar by default offscreen */
  body.mobile #sidebar {
    transform: translateX(-100%);
  }

  /* Overlay behind menu for tap-to-close */
  body.mobile #menu-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 150;
    display: none;
  }

  /* Menu overlay visible */
  body.mobile #menu-overlay.show {
    display: block;
  }

  /* Menu button in top bar */
  body.mobile #top-bar {
    display: flex;
    align-items: center;
    padding: 10px 15px;
    background: #1e1e2f;
    color: #ddd;
    font-size: 1.2em;
    font-weight: bold;
  }

  /* Optional: give title next to button */
  body.mobile #top-bar span {
    margin-left: 15px;
    font-size: 1em;
  }

  /* Adjust viewer below top bar */
  body.mobile #viewer {
    flex: 1;
    height: calc(100vh - 48px); /* exact height of top bar */
    padding: 5px;
    overflow: hidden;
  }


  /* Make tree and search scrollable */
  body.mobile #tree-container,
  body.mobile #results-container {
    max-height: none;
    overflow-y: auto;
  }

  /* Touch-friendly list items */
  body.mobile li {
    padding: 14px 12px !important;
    font-size: 1.1em;
  }

  /* Show top bar ONLY on mobile */
  body.mobile #top-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    height: 48px;
    padding: 0 14px;
    background: #1e1e2f;
    border-bottom: 1px solid #444;
    z-index: 300;
  }

  /* Disable iOS long-press highlight */
  #reset-btn {
    -webkit-touch-callout: none; /* disables callout menu */
    -webkit-user-select: none;   /* prevents selection on iOS Safari */
    -ms-user-select: none;       /* for older Edge */
    user-select: none;           /* standard */
    touch-action: manipulation;  /* prevents long-press highlight / tap delay */
}

/* Make reset and menu buttons slightly bigger on mobile */
body.mobile #reset-btn,
body.mobile #menu-btn {
  padding: 8px 12px;       /* slightly larger tap area */
  font-size: 1em;          /* slightly bigger text */
  border-radius: 6px;      /* optional: keep rounded corners */
}