/* Image viewer and overlays */

  .modal {
    position: fixed;
    inset: 0;
    background: rgba(15,23,42,0.88);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1700;
    padding: 20px;
  }
  .modal.open { display: flex; }
  .viewer {
    position: relative;
    width: min(96vw, 1400px);
    height: min(92vh, 980px);
    background: #020617;
    border-radius: 26px;
    border: 1px solid rgba(255,255,255,0.14);
    overflow: hidden;
  }
  .viewer-toolbar {
    position: absolute;
    top: 12px;
    left: 12px;
    right: 12px;
    display: flex;
    justify-content: space-between;
    gap: 12px;
    z-index: 30;
    align-items: flex-start;
  }
  .viewer-toolbar .row {
    flex-wrap: wrap;
    display: flex;
    gap: 8px;
    align-items: center;
  }
  .viewer-toolbar-main {
    max-width: min(78vw, 980px);
  }
  .viewer-toolbar-side {
    justify-content: flex-end;
    margin-left: auto;
  }
  .viewer-enhance-panel {
    display: inline-flex;
    gap: 8px;
    align-items: center;
    padding: 0;
    border-radius: 16px;
    background: transparent;
    border: 0;
    backdrop-filter: none;
    box-shadow: none;
  }
  .viewer-enhance-panel,
  .viewer-enhance-control,
  .viewer-toolbar button {
    position: relative;
    z-index: 31;
  }
  .viewer-enhance-panel[hidden] {
    display: none;
  }
  .viewer-enhance-control {
    display: grid;
    grid-template-columns: 58px minmax(140px, 1fr) 42px;
    gap: 8px;
    align-items: center;
    font-size: 14px;
    font-weight: 600;
    color: var(--text);
    background: var(--input-bg-strong);
    border: 1px solid var(--line);
    border-radius: 16px;
    padding: 0 15px;
    min-height: 42px;
    line-height: 1.1;
    box-sizing: border-box;
    flex: 0 0 auto;
  }
  .viewer-enhance-control span,
  .viewer-enhance-control output {
    white-space: nowrap;
  }
  .viewer-enhance-control output {
    min-width: 42px;
    text-align: right;
    color: var(--muted);
    font-variant-numeric: tabular-nums;
  }
  .viewer-enhance-control input[type="range"] {
    width: 100%;
    height: 18px;
    margin: 0;
    accent-color: var(--accent);
    align-self: center;
  }
  .viewer-stage {
    position: absolute;
    inset: 0;
    overflow: hidden;
    cursor: grab;
    touch-action: none;
    user-select: none;
    overscroll-behavior: contain;
  }
  .viewer-stage.dragging { cursor: grabbing; }
  #zoomImage,
  #sharpCanvas,
  .viewer-mask-layer {
    position: absolute;
    left: 50%;
    top: 50%;
    transform-origin: center center;
    max-width: none;
    max-height: none;
    user-select: none;
    -webkit-user-drag: none;
  }
  .viewer-mask-layer {
    z-index: 3;
    pointer-events: auto;
  }
  .viewer-mask-layer[hidden] {
    display: none;
  }
  #sharpCanvas {
    display: none;
    pointer-events: none;
    box-shadow: 0 18px 48px rgba(2,6,23,0.24);
  }
  .viewer-stage.sharp-mode #zoomImage {
    display: none;
  }
  .viewer-stage.sharp-mode #sharpCanvas {
    display: block;
  }
  @media (max-width: 1100px) {
    .viewer-toolbar {
      flex-direction: column;
    }
    .viewer-toolbar-side {
      width: 100%;
      justify-content: flex-end;
      margin-left: 0;
    }
    .viewer-label {
      top: 126px;
      left: 18px;
      right: 18px;
    }
    .viewer-label-title {
      font-size: 18px;
      max-width: calc(100vw - 84px);
    }
    .viewer-enhance-panel {
      flex-direction: column;
      align-items: stretch;
      width: min(100%, 280px);
    }
    .viewer-enhance-control {
      grid-template-columns: 58px minmax(140px, 1fr) 42px;
    }
  }

  @media (max-width: 720px) {
    #imageModal.modal {
      align-items: stretch;
      justify-content: stretch;
      padding: 0;
    }

    #imageModal .viewer {
      width: 100vw;
      height: 100vh;
      height: 100dvh;
      border: 0;
      border-radius: 0;
    }

    #imageModal .viewer-toolbar {
      top: max(10px, env(safe-area-inset-top));
      right: max(10px, env(safe-area-inset-right));
      left: max(10px, env(safe-area-inset-left));
      flex-direction: row;
      align-items: flex-start;
      gap: 8px;
      pointer-events: none;
    }

    #imageModal .viewer-toolbar .row,
    #imageModal .viewer-toolbar button,
    #imageModal .viewer-enhance-panel {
      pointer-events: auto;
    }

    #imageModal .viewer-toolbar-main {
      max-width: calc(100vw - 118px - env(safe-area-inset-left) - env(safe-area-inset-right));
      flex-wrap: nowrap;
      overflow-x: auto;
      scrollbar-width: none;
      -webkit-overflow-scrolling: touch;
    }

    #imageModal .viewer-toolbar-main::-webkit-scrollbar {
      display: none;
    }

    #imageModal .viewer-toolbar-side {
      width: auto;
      margin-left: auto;
      flex: 0 0 auto;
    }

    #imageModal .viewer-toolbar button {
      min-height: 40px;
      padding: 0 13px;
      border-radius: 12px;
      white-space: nowrap;
    }

    #imageModal .viewer-enhance-panel {
      position: fixed;
      right: max(10px, env(safe-area-inset-right));
      bottom: max(10px, env(safe-area-inset-bottom));
      left: max(10px, env(safe-area-inset-left));
      display: grid;
      grid-template-columns: repeat(2, minmax(0, 1fr));
      gap: 8px;
      width: auto;
      max-width: none;
      z-index: 40;
    }

    #imageModal .viewer-enhance-control {
      grid-template-columns: minmax(0, 1fr);
      gap: 7px;
      min-height: 70px;
      padding: 10px 12px;
      border-radius: 16px;
      font-size: 13px;
    }

    #imageModal .viewer-enhance-control output {
      display: none;
    }

    #imageModal .viewer-enhance-control input[type="range"] {
      min-width: 0;
      height: 30px;
      touch-action: pan-x;
    }

    #imageModal .viewer-label {
      top: calc(max(10px, env(safe-area-inset-top)) + 54px);
      right: max(12px, env(safe-area-inset-right));
      left: max(12px, env(safe-area-inset-left));
      max-width: none;
    }
  }

  .group-filter-card {
    border: 1px solid var(--line);
    background: linear-gradient(180deg, var(--surface-elevated), var(--surface-raised));
    border-radius: 24px;
    padding: 16px;
    margin-bottom: 16px;
  }
  .group-filter-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
  }
  .group-filter-summary {
    margin-top: 10px;
    border: 1px solid var(--line);
    border-radius: 14px;
    padding: 11px 12px;
    background: var(--accent-soft);
    color: var(--accent-strong);
    font-size: 13px;
    font-weight: 700;
  }
  .quiz-saved-group-preview {
    margin-top: 10px;
    border: 1px solid var(--line);
    border-radius: 16px;
    background: var(--surface-muted);
    padding: 10px;
  }
  .quiz-saved-group-preview[hidden] {
    display: none !important;
  }
  .quiz-saved-group-preview-top {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 10px;
    margin-bottom: 8px;
  }
  .quiz-saved-group-preview-title {
    font-size: 12px;
    font-weight: 800;
    color: var(--text);
  }
  .quiz-saved-group-preview-meta {
    font-size: 11px;
    color: var(--muted);
    font-weight: 700;
  }
  .quiz-saved-group-preview-list {
    display: grid;
    gap: 6px;
    max-height: 148px;
    overflow: auto;
  }
  .quiz-saved-group-preview-item {
    display: grid;
    grid-template-columns: minmax(70px, 92px) minmax(0, 1fr) auto auto;
    gap: 8px;
    align-items: center;
    padding: 7px 9px;
    border-radius: 12px;
    border: 1px solid var(--line);
    background: var(--surface-elevated);
  }
  .quiz-saved-group-preview-code {
    font-size: 11px;
    font-weight: 800;
    color: var(--accent-strong);
  }
  .quiz-saved-group-preview-name {
    min-width: 0;
    color: var(--text);
    font-size: 12px;
    line-height: 1.35;
  }
  .quiz-saved-group-preview-count {
    font-size: 11px;
    font-weight: 700;
    color: var(--muted);
    white-space: nowrap;
  }
  .quiz-saved-group-preview-delete {
    border: 0;
    width: 24px;
    height: 24px;
    border-radius: 999px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: rgba(239, 68, 68, 0.1);
    color: #b91c1c;
    font-size: 14px;
    line-height: 1;
    cursor: pointer;
    opacity: 0;
    transform: scale(0.92);
    transition: opacity 0.16s ease, transform 0.16s ease, background 0.16s ease;
  }
  .quiz-saved-group-preview-item:hover .quiz-saved-group-preview-delete,
  .quiz-saved-group-preview-delete:focus-visible {
    opacity: 1;
    transform: scale(1);
  }
  .quiz-saved-group-preview-delete:hover {
    background: rgba(239, 68, 68, 0.16);
  }
  .quiz-saved-group-preview-delete[hidden] {
    display: none !important;
  }
  .quiz-saved-group-preview-empty {
    padding: 10px;
    border-radius: 12px;
    background: var(--surface-muted);
    color: var(--muted);
    text-align: center;
    font-size: 12px;
    line-height: 1.5;
  }


  #quizGroupSelect[multiple] {
    min-height: 180px;
    padding: 10px;
    border-radius: 18px;
    border: 1px solid var(--line);
    background: linear-gradient(180deg, var(--surface-elevated), var(--surface-raised));
    box-shadow: 0 14px 28px rgba(15,23,42,0.06);
  }
  #quizGroupSelect[multiple] option {
    padding: 10px 12px;
    border-radius: 12px;
  }
  #quizGroupSelect[multiple]:focus {
    outline: none;
    border-color: rgba(37,99,235,0.32);
    box-shadow: 0 0 0 3px rgba(37,99,235,0.10), 0 14px 28px rgba(15,23,42,0.08);
  }
  .saved-group-edit-banner {
    margin: 10px 0 12px;
    padding: 10px 12px;
    border-radius: 14px;
    border: 1px solid rgba(184, 134, 11, 0.28);
    background: linear-gradient(180deg, rgba(255, 249, 219, 0.95), rgba(255, 243, 191, 0.88));
    color: #6b4f00;
    font-size: 12px;
    line-height: 1.45;
    box-shadow: 0 10px 24px rgba(184, 134, 11, 0.08);
  }
  .saved-group-edit-banner strong {
    color: #5a3b00;
  }
  .saved-group-edit-banner-meta {
    display: block;
    margin-top: 3px;
    color: rgba(90, 59, 0, 0.82);
    font-size: 11px;
    font-weight: 700;
  }
  .saved-group-edit-banner[hidden] {
    display: none !important;
  }

  html[data-theme="dark"] #quizGroupSelect[multiple] {
    background: linear-gradient(180deg, rgba(10,18,34,0.98), rgba(15,24,42,0.94));
    border-color: var(--card-border);
    box-shadow: 0 18px 34px rgba(2,6,23,0.32);
  }


  details.quiz-options {
    border: 1px solid var(--line);
    background: linear-gradient(180deg, var(--surface-elevated), var(--surface-raised));
    border-radius: 24px;
    padding: 0;
    margin-bottom: 16px;
    overflow: hidden;
  }
  details.quiz-options summary {
    list-style: none;
    cursor: pointer;
    padding: 16px 18px;
    font-weight: 800;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
  }
  details.quiz-options summary::-webkit-details-marker {
    display: none;
  }
  .quiz-options-summary-text {
    display: flex;
    flex-direction: column;
    gap: 4px;
  }
  .quiz-options-summary-sub {
    font-size: 12px;
    color: var(--muted);
    font-weight: 600;
  }
  .quiz-options-chevron {
    font-size: 18px;
    color: var(--muted);
    transition: transform .18s ease;
  }
  details.quiz-options[open] .quiz-options-chevron {
    transform: rotate(180deg);
  }
  .quiz-options-body {
    padding: 0 16px 16px;
    border-top: 1px solid var(--line);
  }

  .footer {
    margin: 18px auto 0;
    padding: 12px 16px 16px;
    text-align: center;
    color: var(--muted);
    font-size: 12px;
    font-weight: 700;
  }
  .app-footer {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px 12px;
    flex-wrap: wrap;
    letter-spacing: 0.01em;
  }
  .app-footer span + span {
    position: relative;
  }
  .app-footer span + span::before {
    content: "";
    display: inline-block;
    width: 4px;
    height: 4px;
    margin: 0 12px 2px 0;
    border-radius: 999px;
    background: var(--accent);
    opacity: 0.55;
  }
  body.quiz-mode .app-footer {
    display: none;
  }

  html[data-theme="dark"] .viewer-enhance-control,
  html[data-theme="dark"] .quiz-saved-group-preview,
  html[data-theme="dark"] .quiz-saved-group-preview-item,
  html[data-theme="dark"] details.quiz-options {
    background: var(--surface-elevated);
    border-color: var(--line);
    color: var(--text);
  }
  html[data-theme="dark"] .quiz-saved-group-preview-delete {
    background: rgba(127,29,29,0.24);
    color: #fecaca;
  }
  html[data-theme="dark"] .saved-group-edit-banner {
    background: linear-gradient(180deg, rgba(120,53,15,0.24), rgba(18,28,47,0.92));
    border-color: rgba(245, 158, 11, 0.24);
    color: #fcd34d;
    box-shadow: 0 10px 24px rgba(2,6,23,0.26);
  }
html[data-theme="dark"] .saved-group-edit-banner strong,
html[data-theme="dark"] .saved-group-edit-banner-meta {
  color: #fde68a;
}
html[data-theme="dark"] .group-filter-summary {
  background: rgba(96,165,250,0.12);
  color: #dbeafe;
}