/* ─────────────────────────────────────────────────────────────────────────────
   Slides Dashboard, Editor & Viewer Chrome — Material Design 3
   MD3 tokens (--md-*) come from /css/shared.css. Custom selects from /css/dropdown.css.
───────────────────────────────────────────────────────────────────────────── */

* { box-sizing: border-box; }

:root {
  /* Local aliases mapped onto the shared MD3 tonal palette (dark scheme). */
  --bg:            var(--md-surface);
  --surface:       var(--md-surface-container);
  --surface-2:     var(--md-surface-container-high);
  --surface-3:     var(--md-surface-container-highest);
  --text:          var(--md-on-surface);
  --text-2:        var(--md-on-surface-variant);
  --text-3:        var(--md-outline);
  --accent:        var(--md-primary);
  --accent-2:      #a855f7;
  --border:        var(--md-outline-variant);
  --border-strong: var(--md-outline);
  --radius:        var(--md-shape-lg);

  /* Brand gradient kept for decorative surfaces (logo, thumbnails, empty state). */
  --brand-grad: linear-gradient(135deg, #6366f1, #a855f7);
}

html, body {
  margin: 0; padding: 0;
  background: var(--md-surface);
  color: var(--md-on-surface);
  font-family: 'Inter', 'Segoe UI', Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}

/* ── MD3 state-layer helper ── */
.md-state { position: relative; overflow: hidden; isolation: isolate; }
.md-state::after {
  content: ''; position: absolute; inset: 0; z-index: -1;
  background: currentColor; opacity: 0;
  transition: opacity var(--md-duration-s) var(--md-easing-standard);
}
.md-state:hover::after { opacity: 0.08; }
.md-state:active::after { opacity: 0.12; }

/* ── Dashboard ── */
.dashboard {
  min-height: 100vh;
  padding: 0 0 96px;
}

.dash-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 28px;
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--md-surface) 80%, transparent);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--md-outline-variant);
}
.dash-logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 15px; font-weight: 600; color: var(--md-on-surface);
  text-decoration: none;
  padding: 8px 12px 8px 8px; border-radius: var(--md-shape-full);
  transition: background var(--md-duration-s) var(--md-easing-standard);
}
.dash-logo:hover { background: var(--md-surface-container-high); }
.dash-logo svg { opacity: 0.95; }

.dash-content {
  max-width: 1240px;
  margin: 0 auto;
  padding: 44px 28px 0;
}

.dash-title-row {
  display: flex; align-items: flex-end; justify-content: space-between;
  margin-bottom: 32px; gap: 16px;
}
.dash-title {
  font-size: 32px; font-weight: 700; letter-spacing: -0.02em;
  color: var(--md-on-surface);
}
.dash-title span {
  background: var(--brand-grad);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ── MD3 Filled button (primary action / extended FAB) ── */
.btn-create {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 0 24px; height: 48px;
  background: var(--md-primary);
  color: var(--md-on-primary);
  font-size: 14px; font-weight: 600; letter-spacing: 0.01em;
  border: none; border-radius: var(--md-shape-lg); cursor: pointer;
  box-shadow: 0 1px 3px rgba(0,0,0,0.3), 0 4px 8px rgba(0,0,0,0.15);
  transition: box-shadow var(--md-duration-m) var(--md-easing-standard),
              filter var(--md-duration-s) var(--md-easing-standard);
  position: relative; overflow: hidden; isolation: isolate;
}
.btn-create::after {
  content: ''; position: absolute; inset: 0; z-index: -1;
  background: var(--md-on-primary); opacity: 0;
  transition: opacity var(--md-duration-s) var(--md-easing-standard);
}
.btn-create:hover { box-shadow: 0 2px 6px rgba(0,0,0,0.35), 0 8px 20px rgba(0,0,0,0.22); }
.btn-create:hover::after { opacity: 0.08; }
.btn-create:active::after { opacity: 0.12; }

/* ── Grid of presentation cards ── */
.pres-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 20px;
}

/* MD3 filled card */
.pres-card {
  background: var(--md-surface-container);
  border: 1px solid transparent;
  border-radius: var(--md-shape-md);
  overflow: hidden;
  cursor: pointer;
  transition: background var(--md-duration-s) var(--md-easing-standard),
              transform var(--md-duration-m) var(--md-easing-standard),
              box-shadow var(--md-duration-m) var(--md-easing-standard);
  text-decoration: none;
}
.pres-card:hover {
  background: var(--md-surface-container-high);
  transform: translateY(-3px);
  box-shadow: 0 8px 28px rgba(0,0,0,0.4);
}

.pres-card-thumb {
  height: 160px;
  position: relative;
  overflow: hidden;
  display: flex; align-items: center; justify-content: center;
}
.pres-card-thumb-gradient-dark  { background: linear-gradient(135deg, #0f172a, #1e293b); }
.pres-card-thumb-minimal-light  { background: linear-gradient(135deg, #faf9f7, #f3f0eb); }
.pres-card-thumb-bold-color     { background: linear-gradient(135deg, #0d0d0d, #1a1a2e); }
.pres-card-thumb-corporate      { background: linear-gradient(135deg, #0a0a0f, #141420); }
.pres-card-thumb-editorial      { background: linear-gradient(135deg, #f7f4ee, #ece6db); }
.pres-card-thumb-vibrant        { background: linear-gradient(135deg, #0a0a12, #16121f); }

.pres-card-thumb-decor {
  position: absolute; border-radius: 50%; filter: blur(40px);
}

.thumb-label {
  position: relative; z-index: 1;
  font-size: 16px; font-weight: 700; letter-spacing: -0.01em;
  text-align: center; padding: 16px;
  line-height: 1.3;
}
.pres-card-thumb-gradient-dark .thumb-label  { color: #f1f5f9; }
.pres-card-thumb-minimal-light .thumb-label  { color: #1c1917; }
.pres-card-thumb-bold-color    .thumb-label  { color: #ffffff; }
.pres-card-thumb-corporate     .thumb-label  { color: #e2e8f0; }
.pres-card-thumb-editorial     .thumb-label  { color: #1a1714; }
.pres-card-thumb-vibrant       .thumb-label  { color: #ffffff; }

.pres-card-body {
  padding: 16px 18px;
}
.pres-card-meta {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 6px;
}
.pres-card-title {
  font-size: 14px; font-weight: 600; color: var(--md-on-surface);
  white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
  flex: 1; margin-right: 8px;
}
.pres-card-count {
  font-size: 11px; color: var(--md-on-surface-variant);
  flex-shrink: 0;
}
.pres-card-date {
  font-size: 11px; color: var(--md-on-surface-variant);
}

.pres-card-actions {
  display: flex; align-items: center; gap: 8px;
  padding: 10px 18px 14px;
  border-top: 1px solid var(--md-outline-variant);
}
/* MD3 text/tonal chip button */
.btn-card {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 0 14px; height: 32px;
  font-size: 12px; font-weight: 600; color: var(--md-on-surface-variant);
  background: transparent; border: 1px solid var(--md-outline-variant);
  border-radius: var(--md-shape-full); cursor: pointer; text-decoration: none;
  transition: background var(--md-duration-s) var(--md-easing-standard),
              color var(--md-duration-s) var(--md-easing-standard),
              border-color var(--md-duration-s) var(--md-easing-standard);
}
.btn-card:hover { background: var(--md-surface-container-highest); color: var(--md-on-surface); }
.btn-card-danger:hover { color: #ffb4ab; border-color: rgba(255,180,171,0.4); background: rgba(255,180,171,0.08); }

/* ── Empty state ── */
.empty-state {
  text-align: center;
  padding: 88px 32px;
}
.empty-icon {
  font-size: 56px; margin-bottom: 16px;
}
.empty-title { font-size: 22px; font-weight: 600; margin: 0 0 8px; color: var(--md-on-surface); }
.empty-body  { color: var(--md-on-surface-variant); font-size: 15px; margin: 0 0 28px; }
.empty-state .btn-create { display: inline-flex; }

/* ── MD3 Dialog ── */
.modal-overlay {
  position: fixed; inset: 0; z-index: 200;
  background: rgba(0,0,0,0.5);
  display: flex; align-items: center; justify-content: center;
  padding: 20px;
  opacity: 0; pointer-events: none;
  transition: opacity var(--md-duration-m) var(--md-easing-standard);
}
.modal-overlay.open { opacity: 1; pointer-events: all; }

.modal-box {
  background: var(--md-surface-container-high);
  border: none;
  border-radius: var(--md-shape-xl);
  padding: 28px 28px 24px;
  width: 100%; max-width: 540px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.45), 0 2px 8px rgba(0,0,0,0.3);
  transform: translateY(24px) scale(0.96);
  transition: transform var(--md-duration-m) var(--md-easing-enter);
}
.modal-overlay.open .modal-box { transform: translateY(0) scale(1); }

.modal-title { font-size: 22px; font-weight: 600; margin: 0 0 8px; color: var(--md-on-surface); }
.modal-desc  { color: var(--md-on-surface-variant); font-size: 14px; line-height: 1.5; margin: 0 0 24px; }

.form-group { margin-bottom: 18px; }
.form-label {
  display: block; font-size: 12px; font-weight: 500;
  color: var(--md-primary); margin-bottom: 7px; letter-spacing: 0.02em;
}
/* MD3 outlined text field */
.form-input, .form-textarea {
  width: 100%; background: transparent; color: var(--md-on-surface);
  border: 1px solid var(--md-outline);
  border-radius: var(--md-shape-sm); padding: 13px 15px;
  font-size: 14px; font-family: inherit;
  transition: border-color var(--md-duration-s) var(--md-easing-standard),
              box-shadow var(--md-duration-s) var(--md-easing-standard);
  outline: none;
  resize: vertical;
}
.form-input::placeholder, .form-textarea::placeholder { color: var(--md-on-surface-variant); opacity: 0.7; }
.form-input:focus, .form-textarea:focus {
  border-color: var(--md-primary);
  box-shadow: inset 0 0 0 1px var(--md-primary);
}
.form-textarea { min-height: 120px; line-height: 1.5; }

/* Form hint (optional label marker) */
.form-hint { font-weight: 400; opacity: 0.6; font-size: 11px; text-transform: none; letter-spacing: 0; }

/* Options row — tone / verbosity / language / model side by side */
.form-options-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr 1fr;
  gap: 14px;
  margin-bottom: 6px;
}
.form-group-half { margin-bottom: 14px; }

@media (max-width: 640px) {
  .form-options-row { grid-template-columns: 1fr 1fr; }
}

/* MD3 outlined select — matches .form-input */
select.form-input {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath d='M3 5l3 3 3-3' stroke='%2394a3b8' stroke-width='1.4' stroke-linecap='round' stroke-linejoin='round' fill='none'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 36px;
  cursor: pointer;
}
select.form-input option {
  background: var(--md-surface-container-high);
  color: var(--md-on-surface);
}

/* Checkboxes row */
.form-checkboxes {
  margin-bottom: 18px;
  display: flex; flex-wrap: wrap; gap: 16px;
}
.form-checkbox {
  display: inline-flex; align-items: center; gap: 9px;
  font-size: 13px; color: var(--md-on-surface-variant);
  cursor: pointer; user-select: none;
}
.form-checkbox input[type="checkbox"] { display: none; }
.checkmark {
  width: 18px; height: 18px;
  border: 2px solid var(--md-outline);
  border-radius: 4px;
  display: inline-flex; align-items: center; justify-content: center;
  transition: background var(--md-duration-s) var(--md-easing-standard),
              border-color var(--md-duration-s) var(--md-easing-standard);
  flex-shrink: 0;
}
.checkmark::after {
  content: ''; width: 6px; height: 10px;
  border: solid transparent; border-width: 0 2px 2px 0;
  transform: rotate(45deg) translateY(-1px);
  opacity: 0;
  transition: opacity var(--md-duration-s);
}
.form-checkbox input:checked + .checkmark {
  background: var(--md-primary); border-color: var(--md-primary);
}
.form-checkbox input:checked + .checkmark::after {
  border-color: var(--md-on-primary); opacity: 1;
}

/* File upload area */
.file-upload-area {
  border: 2px dashed var(--md-outline-variant);
  border-radius: var(--md-shape-sm);
  padding: 20px 18px;
  cursor: pointer;
  transition: border-color var(--md-duration-s) var(--md-easing-standard),
              background var(--md-duration-s) var(--md-easing-standard);
}
.file-upload-area:hover, .file-upload-area.drag-over {
  border-color: var(--md-primary);
  background: color-mix(in srgb, var(--md-primary) 4%, transparent);
}
.file-input { display: none; }
.file-upload-content {
  display: flex; flex-direction: column; align-items: center; gap: 8px;
  color: var(--md-on-surface-variant); font-size: 13px;
}
.file-upload-content svg { opacity: 0.5; }
.file-list { margin-top: 12px; display: flex; flex-direction: column; gap: 6px; }
.file-item {
  display: flex; align-items: center; gap: 10px;
  padding: 8px 12px;
  background: var(--md-surface-container);
  border-radius: var(--md-shape-sm);
  font-size: 13px; color: var(--md-on-surface);
}
.file-item-icon {
  width: 32px; height: 32px;
  display: flex; align-items: center; justify-content: center;
  border-radius: 6px; background: var(--md-surface-container-high);
  font-size: 14px; color: var(--md-primary); flex-shrink: 0;
}
.file-item-name { flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.file-item-size { font-size: 11px; color: var(--md-on-surface-variant); flex-shrink: 0; }
.file-item-remove {
  width: 24px; height: 24px; display: flex; align-items: center; justify-content: center;
  border: none; background: transparent; color: var(--md-on-surface-variant); cursor: pointer;
  border-radius: 50%; font-size: 16px; flex-shrink: 0;
  transition: background var(--md-duration-s);
}
.file-item-remove:hover { background: rgba(255,180,171,0.15); color: #ffb4ab; }

.modal-footer {
  display: flex; justify-content: flex-end; gap: 8px;
  margin-top: 24px;
}
/* MD3 text button */
.btn-cancel {
  padding: 0 20px; height: 40px; background: transparent; color: var(--md-primary);
  border: none; border-radius: var(--md-shape-full);
  font-size: 14px; font-weight: 600; cursor: pointer;
  transition: background var(--md-duration-s) var(--md-easing-standard);
}
.btn-cancel:hover { background: color-mix(in srgb, var(--md-primary) 8%, transparent); }
/* MD3 filled button */
.btn-submit {
  padding: 0 24px; height: 40px;
  background: var(--md-primary);
  color: var(--md-on-primary); border: none; border-radius: var(--md-shape-full);
  font-size: 14px; font-weight: 600; cursor: pointer;
  transition: filter var(--md-duration-s) var(--md-easing-standard), opacity var(--md-duration-s);
  display: flex; align-items: center; gap: 8px;
  position: relative; overflow: hidden; isolation: isolate;
}
.btn-submit::after {
  content: ''; position: absolute; inset: 0; z-index: -1;
  background: var(--md-on-primary); opacity: 0;
  transition: opacity var(--md-duration-s) var(--md-easing-standard);
}
.btn-submit:hover::after { opacity: 0.08; }
.btn-submit:active::after { opacity: 0.12; }
.btn-submit:disabled { opacity: 0.5; cursor: not-allowed; }

/* Generating animation */
.generating-spinner {
  width: 18px; height: 18px;
  border: 2px solid color-mix(in srgb, var(--md-on-primary) 30%, transparent);
  border-top-color: var(--md-on-primary);
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
  display: none;
}
.generating .generating-spinner { display: block; }
.generating .submit-label { opacity: 0.7; }

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

/* ── MD3 Snackbar (toast) ── */
.toast {
  position: fixed; bottom: 28px; left: 50%; transform: translateX(-50%) translateY(80px);
  background: var(--md-surface-container-highest);
  border: 1px solid var(--md-outline-variant);
  color: var(--md-on-surface); padding: 14px 22px;
  border-radius: var(--md-shape-xs); font-size: 14px; font-weight: 500;
  box-shadow: 0 4px 16px rgba(0,0,0,0.4);
  transition: transform var(--md-duration-m) var(--md-easing-enter), opacity var(--md-duration-m);
  z-index: 300; pointer-events: none; opacity: 0;
  white-space: nowrap;
}
.toast.show { transform: translateX(-50%) translateY(0); opacity: 1; }
.toast.error { color: #ffb4ab; border-color: rgba(255,180,171,0.4); }

/* ── Actionable error modal (see js/errors.js) ── */
.err-modal-overlay {
  position: fixed; inset: 0; z-index: 1000;
  display: flex; align-items: center; justify-content: center;
  padding: 20px; background: rgba(0,0,0,0.5); backdrop-filter: blur(2px);
  opacity: 0; transition: opacity var(--md-duration-m) ease;
}
.err-modal-overlay.show { opacity: 1; }
.err-modal {
  width: 100%; max-width: 420px;
  background: var(--md-surface-container-high); border: none;
  border-radius: var(--md-shape-xl); padding: 28px;
  box-shadow: 0 8px 24px rgba(0,0,0,0.45);
  transform: translateY(16px) scale(0.96); transition: transform var(--md-duration-m) var(--md-easing-enter);
}
.err-modal-overlay.show .err-modal { transform: translateY(0) scale(1); }
.err-modal-title { margin: 0 0 10px; font-size: 20px; font-weight: 600; color: var(--md-on-surface); }
.err-modal-body { margin: 0 0 24px; font-size: 14.5px; line-height: 1.6; color: var(--md-on-surface-variant); }
.err-modal-actions { display: flex; justify-content: flex-end; gap: 8px; }
.err-btn {
  padding: 0 20px; height: 40px; border-radius: var(--md-shape-full); font-size: 14px; font-weight: 600;
  cursor: pointer; border: none; transition: filter var(--md-duration-s), background var(--md-duration-s), transform 0.1s;
  display: inline-flex; align-items: center;
}
.err-btn:active { transform: scale(0.97); }
.err-btn:disabled { opacity: 0.55; cursor: default; }
.err-btn-primary { background: var(--md-primary); color: var(--md-on-primary); }
.err-btn-primary:hover:not(:disabled) { filter: brightness(1.08); }
.err-btn-ghost { background: transparent; color: var(--md-primary); }
.err-btn-ghost:hover { background: color-mix(in srgb, var(--md-primary) 8%, transparent); }

/* ── Viewer chrome ── */
.viewer-toolbar {
  position: fixed; bottom: 24px; right: 24px;
  display: flex; flex-direction: column; gap: 8px;
  z-index: 100;
}
/* MD3 tonal icon button */
.btn-tool {
  width: 44px; height: 44px;
  background: color-mix(in srgb, var(--md-surface-container-high) 88%, transparent);
  border: 1px solid var(--md-outline-variant);
  border-radius: var(--md-shape-full); cursor: pointer; color: var(--md-on-surface-variant);
  display: flex; align-items: center; justify-content: center;
  backdrop-filter: blur(10px);
  transition: background var(--md-duration-s) var(--md-easing-standard),
              color var(--md-duration-s) var(--md-easing-standard),
              border-color var(--md-duration-s) var(--md-easing-standard);
  font-size: 16px; text-decoration: none;
  position: relative;
}
.btn-tool:hover {
  background: var(--md-primary-container); color: var(--md-on-primary-container);
  border-color: transparent;
}
.btn-tool-label {
  position: absolute; right: calc(100% + 10px); top: 50%;
  transform: translateY(-50%);
  background: var(--md-surface-container-highest); color: var(--md-on-surface);
  font-size: 12px; white-space: nowrap; padding: 6px 11px;
  border-radius: var(--md-shape-xs); pointer-events: none; opacity: 0;
  box-shadow: 0 2px 8px rgba(0,0,0,0.35);
  transition: opacity var(--md-duration-s);
}
.btn-tool:hover .btn-tool-label { opacity: 1; }

/* Keep Reveal's slide number clear of the bottom-right toolbar column */
.reveal .slide-number {
  left: 12px; right: auto;
  bottom: 12px; top: auto;
}

/* ── Progress counter (n / total) — bottom-left, toggles the overview ── */
.slide-counter {
  position: fixed; bottom: 24px; left: 24px; z-index: 110;
  display: flex; align-items: center; gap: 8px;
  background: color-mix(in srgb, var(--md-surface-container-high) 88%, transparent);
  border: 1px solid var(--md-outline-variant);
  border-radius: var(--md-shape-full); padding: 10px 16px;
  color: var(--md-on-surface-variant); font: 500 13px/1 Inter, system-ui, sans-serif;
  cursor: pointer; user-select: none; backdrop-filter: blur(10px);
  transition: background var(--md-duration-s) var(--md-easing-standard),
              color var(--md-duration-s) var(--md-easing-standard),
              border-color var(--md-duration-s) var(--md-easing-standard);
}
.slide-counter:hover { background: var(--md-primary-container); color: var(--md-on-primary-container); border-color: transparent; }
.slide-counter svg { opacity: 0.8; flex-shrink: 0; }
.slide-counter:hover svg { opacity: 1; }
.slide-counter .sc-cur { color: var(--md-on-surface); font-weight: 600; }
.slide-counter:hover .sc-cur { color: var(--md-on-primary-container); }
.slide-counter .sc-sep { opacity: 0.4; }

/* ── Slide sidebar (left filmstrip) ── */
.thumb-sidebar {
  position: fixed; top: 0; left: 0; bottom: 0; width: 256px; z-index: 150;
  display: flex; flex-direction: column;
  background: color-mix(in srgb, var(--md-surface-container) 96%, transparent);
  backdrop-filter: blur(18px);
  border-right: 1px solid var(--md-outline-variant);
  transform: translateX(-100%);
  transition: transform var(--md-duration-m) var(--md-easing-standard);
}
.thumb-sidebar.open { transform: translateX(0); box-shadow: 8px 0 40px rgba(0,0,0,0.45); }
.thumb-sidebar-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 18px; flex-shrink: 0;
  border-bottom: 1px solid var(--md-outline-variant);
  color: var(--md-on-surface); font: 600 13px Inter, system-ui, sans-serif; letter-spacing: 0.02em;
}
.thumb-list {
  flex: 1; overflow-y: auto; overflow-x: hidden;
  padding: 14px; display: flex; flex-direction: column; gap: 14px;
  scrollbar-width: thin; scrollbar-color: color-mix(in srgb, var(--md-primary) 45%, transparent) transparent;
}
.thumb-list::-webkit-scrollbar { width: 8px; }
.thumb-list::-webkit-scrollbar-track { background: transparent; margin: 6px 0; }
.thumb-list::-webkit-scrollbar-thumb {
  background: color-mix(in srgb, var(--md-primary) 55%, transparent);
  border-radius: 999px; border: 2px solid transparent; background-clip: content-box;
}
/* In the narrow filmstrip, the number sits in the corner of each thumbnail. */
.thumb-list .thumb-item { position: relative; gap: 0; }
.thumb-list .thumb-num {
  position: absolute; right: 6px; bottom: 6px; z-index: 2;
  padding: 1px 7px; border-radius: var(--md-shape-xs);
  background: rgba(0,0,0,0.6); backdrop-filter: blur(4px);
  color: #fff; font-size: 11px;
}

/* ── Slide overview (full-screen thumbnail grid / slide sorter) ── */
.thumb-overview {
  position: fixed; inset: 0; z-index: 150;
  display: flex; flex-direction: column;
  background: color-mix(in srgb, var(--md-surface) 97%, transparent); backdrop-filter: blur(12px);
  opacity: 0; visibility: hidden; transform: scale(0.985);
  transition: opacity var(--md-duration-m) ease, transform var(--md-duration-m) ease, visibility var(--md-duration-m);
}
.thumb-overview.open { opacity: 1; visibility: visible; transform: scale(1); }
.thumb-overview-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 28px; flex-shrink: 0;
  border-bottom: 1px solid var(--md-outline-variant);
}
.thumb-overview-title {
  color: var(--md-on-surface); font: 600 15px Inter, system-ui, sans-serif; letter-spacing: 0.01em;
}
.thumb-panel-close {
  display: flex; padding: 8px; background: none; border: none; border-radius: var(--md-shape-full);
  color: var(--md-on-surface-variant); cursor: pointer;
  transition: background var(--md-duration-s), color var(--md-duration-s);
}
.thumb-panel-close:hover { background: var(--md-surface-container-highest); color: var(--md-on-surface); }
.thumb-grid {
  flex: 1; overflow-y: auto; overflow-x: hidden;
  padding: 28px;
  display: grid; gap: 28px 24px; align-content: start;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  scrollbar-width: thin;
  scrollbar-color: color-mix(in srgb, var(--md-primary) 45%, transparent) transparent;
}
.thumb-grid::-webkit-scrollbar { width: 10px; }
.thumb-grid::-webkit-scrollbar-track { background: transparent; margin: 6px 0; }
.thumb-grid::-webkit-scrollbar-thumb {
  background: color-mix(in srgb, var(--md-primary) 55%, transparent);
  border-radius: 999px; border: 2px solid transparent; background-clip: content-box;
}
.thumb-grid::-webkit-scrollbar-thumb:hover {
  background: color-mix(in srgb, var(--md-primary) 85%, transparent);
  border: 2px solid transparent; background-clip: content-box;
}
.thumb-item {
  display: flex; flex-direction: column; gap: 8px;
  cursor: pointer;
}
.thumb-frame {
  position: relative; width: 100%; aspect-ratio: 16 / 9; overflow: hidden;
  border-radius: var(--md-shape-sm); background: #000;
  border: 2px solid transparent; box-shadow: 0 4px 14px rgba(0,0,0,0.4);
  transition: border-color var(--md-duration-s), transform var(--md-duration-s), box-shadow var(--md-duration-s);
}
.thumb-item:hover .thumb-frame {
  border-color: color-mix(in srgb, var(--md-primary) 60%, transparent); transform: translateY(-2px);
  box-shadow: 0 8px 22px rgba(0,0,0,0.5);
}
.thumb-item.active .thumb-frame {
  border-color: var(--md-primary);
  box-shadow: 0 0 0 2px var(--md-primary), 0 6px 20px color-mix(in srgb, var(--md-primary) 30%, transparent);
}
.thumb-scale {
  position: absolute; top: 0; left: 0;
  width: 1280px; height: 720px; transform-origin: top left;
  pointer-events: none;
}
.thumb-num {
  color: var(--md-on-surface-variant); font: 500 14px Inter, system-ui, sans-serif; padding-left: 2px;
}
.thumb-item.active .thumb-num { color: var(--md-on-surface); }

/* ── Reveal.js print tweaks ── */
@media print {
  .viewer-toolbar, .thumb-overview, .slide-counter { display: none !important; }
}

/* ── Loading screen ── */
.loading-screen {
  position: fixed; inset: 0; z-index: 500;
  background: var(--md-surface);
  display: flex; flex-direction: column; align-items: center; justify-content: center;
  gap: 20px; transition: opacity var(--md-duration-l);
}
.loading-screen.hidden { opacity: 0; pointer-events: none; }
.loading-dots {
  display: flex; gap: 8px;
}
.loading-dots span {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--brand-grad);
  animation: bounce 1.2s ease-in-out infinite;
}
.loading-dots span:nth-child(2) { animation-delay: 0.2s; }
.loading-dots span:nth-child(3) { animation-delay: 0.4s; }
@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}
.loading-text { color: var(--md-on-surface-variant); font-size: 14px; }

@media (prefers-reduced-motion: reduce) {
  .generating-spinner { animation: none; opacity: 0.7; }
  .loading-dots span { animation: none; }
  * { transition-duration: 0.01ms !important; }
}