:root {
  --bg: #f4f5f7;
  --panel-bg: #ffffff;
  --text: #1a1d21;
  --muted: #6b7280;
  --border: #dde1e6;
  --accent: #7c5cff;
  --accent-contrast: #ffffff;
  --danger: #d64545;
  --page-shadow: 0 2px 10px rgba(0, 0, 0, 0.12);
  --radius: 10px;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16181d;
    --panel-bg: #1e2127;
    --text: #e8e9ec;
    --muted: #9aa0aa;
    --border: #30343c;
    --accent: #9b82ff;
    --accent-contrast: #14151a;
    --page-shadow: 0 2px 14px rgba(0, 0, 0, 0.5);
  }
}

* { box-sizing: border-box; }

html, body {
  height: 100%;
  margin: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
}

#app {
  height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ---------- Topbar ---------- */

#topbar {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 14px;
  background: var(--panel-bg);
  border-bottom: 1px solid var(--border);
  flex-wrap: wrap;
  z-index: 20;
}

.brand {
  font-weight: 700;
  font-size: 15px;
  white-space: nowrap;
  margin-right: 4px;
}

.toolbar-group {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 4px 8px;
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--bg) 60%, transparent);
}

.spacer { flex: 1; }

.slider-label {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 12px;
  color: var(--muted);
  white-space: nowrap;
}

#speed-readout, #page-readout {
  font-size: 12px;
  color: var(--muted);
  min-width: 60px;
}

.progress-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1;
  max-width: 360px;
}

.progress-wrap input[type="range"] { flex: 1; }

/* ---------- Buttons / inputs ---------- */

.btn {
  border: 1px solid var(--border);
  background: var(--panel-bg);
  color: var(--text);
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 13px;
  cursor: pointer;
  white-space: nowrap;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  transition: background 0.15s, transform 0.05s;
}
.btn:hover:not(:disabled) { background: color-mix(in srgb, var(--accent) 12%, var(--panel-bg)); }
.btn:active:not(:disabled) { transform: scale(0.97); }
.btn:disabled { opacity: 0.45; cursor: not-allowed; }

.btn.primary {
  background: var(--accent);
  color: var(--accent-contrast);
  border-color: var(--accent);
}
.btn.primary:hover { filter: brightness(1.06); }

.btn.small { padding: 5px 10px; font-size: 12.5px; }
.btn.danger { color: var(--danger); border-color: color-mix(in srgb, var(--danger) 40%, var(--border)); }
.btn.icon-btn { padding: 6px 9px; font-size: 15px; }

input[type="range"] { accent-color: var(--accent); }
input[type="text"], input[type="password"], select, textarea {
  font-family: inherit;
  font-size: 13px;
  color: var(--text);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 6px 8px;
}

/* ---------- Layout ---------- */

#layout {
  flex: 1;
  display: flex;
  min-height: 0;
}

#reader-pane {
  flex: 1;
  overflow-y: auto;
  overflow-x: hidden;
  position: relative;
  scroll-behavior: auto;
  padding: 24px 0 60vh;
  display: flex;
  flex-direction: column;
  align-items: center;
}

#drop-zone {
  width: min(90%, 640px);
  margin-top: 10vh;
  padding: 40px 30px;
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  text-align: center;
  color: var(--muted);
}
#drop-zone.drag-over {
  border-color: var(--accent);
  background: color-mix(in srgb, var(--accent) 6%, transparent);
}
#drop-zone p { margin: 6px 0; }
.muted { color: var(--muted); }
.small { font-size: 12px; }

#pages-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 18px;
  width: 100%;
}
#pages-container:empty { display: none; }

.doc-page {
  position: relative;
  background: #fff;
  box-shadow: var(--page-shadow);
  border-radius: 2px;
}

.pdf-page canvas { display: block; }

.doc-flow-page {
  width: min(92%, 760px);
  background: var(--panel-bg);
  box-shadow: var(--page-shadow);
  border-radius: var(--radius);
  padding: 40px 48px;
  color: #1a1d21;
  line-height: 1.6;
}
.doc-flow-page img { max-width: 100%; }

.slide-page {
  width: min(92%, 900px);
  aspect-ratio: 16 / 9;
  background: linear-gradient(160deg, #ffffff, #eef0f5);
  box-shadow: var(--page-shadow);
  border-radius: var(--radius);
  padding: 36px 44px;
  color: #1a1d21;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}
.slide-page h2 { margin-top: 0; }
.slide-number {
  position: absolute;
  bottom: 10px;
  right: 14px;
  font-size: 12px;
  color: #9aa0aa;
}

.text-block.reading-active {
  background: color-mix(in srgb, var(--accent) 25%, transparent);
  border-radius: 3px;
  box-shadow: 0 0 0 2px color-mix(in srgb, var(--accent) 30%, transparent);
}

/* selection floating toolbar */
#selection-toolbar {
  position: absolute;
  display: flex;
  gap: 6px;
  background: var(--panel-bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 5px;
  box-shadow: 0 4px 16px rgba(0,0,0,0.18);
  z-index: 50;
}

/* ---------- Side panel ---------- */

#side-panel {
  width: 380px;
  flex-shrink: 0;
  border-left: 1px solid var(--border);
  background: var(--panel-bg);
  display: flex;
  flex-direction: column;
  min-height: 0;
}

.panel {
  display: flex;
  flex-direction: column;
  min-height: 0;
  flex: 1;
}

.panel-header {
  padding: 14px 16px 8px;
  border-bottom: 1px solid var(--border);
}
.panel-header h2 { margin: 0 0 4px; font-size: 15px; }

.panel-body {
  flex: 1;
  overflow-y: auto;
  padding: 14px 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.panel-footer {
  padding: 10px 16px;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 8px;
  justify-content: flex-end;
}

#notes-text {
  width: 100%;
  min-height: 140px;
  resize: vertical;
}

#ai-panel {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 10px 12px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  background: color-mix(in srgb, var(--bg) 50%, transparent);
}
.ai-panel-header { display: flex; align-items: baseline; justify-content: space-between; }
.ai-panel-header h3 { margin: 0; font-size: 13px; }
.ai-output {
  font-size: 13px;
  line-height: 1.5;
  white-space: pre-wrap;
  max-height: 260px;
  overflow-y: auto;
  min-height: 40px;
}
.ai-actions, .summarize-row { display: flex; gap: 8px; align-items: center; }
.summarize-row select { flex: 1; }

fieldset {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
legend { padding: 0 6px; font-size: 12.5px; color: var(--muted); }

.field {
  display: flex;
  flex-direction: column;
  gap: 4px;
  font-size: 12.5px;
  color: var(--muted);
}
.field input, .field select { color: var(--text); }
.field.checkbox {
  flex-direction: row;
  align-items: center;
  gap: 8px;
}

/* ---------- Toast ---------- */

#toast {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--text);
  color: var(--bg);
  padding: 9px 16px;
  border-radius: 8px;
  font-size: 13px;
  z-index: 100;
  box-shadow: 0 6px 20px rgba(0,0,0,0.25);
}

/* ---------- Export modal ---------- */

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
}
.modal-overlay[hidden] {
  display: none;
}

.modal {
  width: min(92%, 480px);
  max-height: 88vh;
  overflow-y: auto;
  background: var(--panel-bg);
  border-radius: var(--radius);
  padding: 22px 24px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.35);
}
.modal h2 { margin: 0 0 6px; font-size: 17px; }

#export-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin: 14px 0;
}

.modal-actions {
  display: flex;
  gap: 10px;
  justify-content: flex-end;
  margin-top: 10px;
}

#export-live, #export-result {
  margin-top: 14px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  align-items: center;
}
#export-canvas, #export-preview-video {
  width: 100%;
  max-height: 360px;
  object-fit: contain;
  background: #000;
  border-radius: 8px;
}

@media (max-width: 860px) {
  #side-panel { position: fixed; right: 0; top: 49px; bottom: 0; width: 100%; max-width: 380px; box-shadow: -6px 0 20px rgba(0,0,0,0.2); }
}