/* ========================================
   NBLM 簡報生成助手 — Dark Theme
   ======================================== */

/* --- CSS Variables --- */
:root {
  --bg-primary: #0a0a0f;
  --bg-card: #14141f;
  --bg-surface: #1a1a2e;
  --accent: #00d4aa;
  --accent-hover: #00f0c0;
  --accent-glow: rgba(0, 212, 170, 0.15);
  --text-primary: #e8e8e8;
  --text-secondary: #a0a0b0;
  --border: #2a2a3e;
  --danger: #ff4757;
  --success: #2ed573;
  --info: #3498db;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.3s ease;
  --font: 'Noto Sans TC', sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Cascadia Code', monospace;
}

/* --- Global Reset --- */
*,
*::before,
*::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ========================================
   Header
   ======================================== */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 32px;
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
}

.header-brand {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.header-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  display: flex;
  align-items: center;
  gap: 12px;
}

.header-logo {
  height: 32px;
  width: auto;
  vertical-align: middle;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-5px);
  }
}

.btn-api-key {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
}

/* ========================================
   Main
   ======================================== */
.app-main {
  flex: 1;
  max-width: 1100px;
  width: 100%;
  margin: 0 auto;
  padding: 24px 24px 48px;
}

/* ========================================
   Mode Tabs
   ======================================== */
.mode-tabs {
  display: flex;
  gap: 4px;
  background: var(--bg-card);
  border-radius: var(--radius);
  padding: 4px;
  margin-bottom: 28px;
}

.mode-tab {
  flex: 1;
  padding: 12px 20px;
  background: transparent;
  border: none;
  color: var(--text-secondary);
  font-family: var(--font);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
  position: relative;
}

.mode-tab:hover {
  color: var(--text-primary);
  background: var(--bg-surface);
}

.mode-tab.active {
  color: var(--bg-primary);
  background: var(--accent);
  font-weight: 700;
}

/* ========================================
   Step Progress Bar
   ======================================== */
.step-progress {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  margin-bottom: 32px;
  padding: 0 40px;
}

.step-progress.hidden {
  display: none;
}

.step-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  position: relative;
}

.step-dot {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 2px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--text-secondary);
  background: var(--bg-card);
  transition: all var(--transition);
}

.step-label {
  font-size: 0.75rem;
  color: var(--text-secondary);
  white-space: nowrap;
  transition: color var(--transition);
}

.step-item.active .step-dot {
  border-color: var(--accent);
  background: var(--accent);
  color: var(--bg-primary);
}

.step-item.active .step-label {
  color: var(--accent);
  font-weight: 500;
}

.step-item.completed .step-dot {
  border-color: var(--accent);
  background: transparent;
  color: var(--accent);
}

.step-item.completed .step-label {
  color: var(--accent);
}

.step-line {
  flex: 1;
  height: 2px;
  background: var(--border);
  margin: 0 8px;
  margin-bottom: 22px;
  min-width: 40px;
  transition: background var(--transition);
}

.step-line.active {
  background: var(--accent);
}

/* ========================================
   Step Panels
   ======================================== */
.step-panel {
  animation: fadeIn 0.3s ease;
}

.step-panel.hidden {
  display: none;
}

.panel-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.panel-desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  margin-bottom: 28px;
}

/* ========================================
   Card Selectors (Step 1)
   ======================================== */
.card-section {
  margin-bottom: 32px;
}

.card-section-title {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 14px;
  padding-left: 2px;
}

.category-badge {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 500;
  padding: 3px 10px;
  border-radius: 20px;
  margin-bottom: 10px;
  margin-top: 8px;
}

.category-badge.category-edu {
  background: rgba(0, 212, 170, 0.12);
  color: var(--accent);
}

.category-badge.category-work {
  background: rgba(52, 152, 219, 0.12);
  color: var(--info);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 12px;
  margin-bottom: 8px;
}

.preset-card {
  padding: 16px 12px;
  background: var(--bg-card);
  border: 2px solid var(--border);
  border-radius: var(--radius);
  cursor: pointer;
  text-align: center;
  transition: all var(--transition);
  user-select: none;
}

.preset-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 8px 24px var(--accent-glow);
  border-color: rgba(0, 212, 170, 0.4);
}

.preset-card.selected {
  border-color: var(--accent);
  background: rgba(0, 212, 170, 0.06);
}

.preset-card .card-emoji {
  font-size: 1.8rem;
  display: block;
  margin-bottom: 6px;
  transition: transform var(--transition);
}

.preset-card.selected .card-emoji {
  transform: scale(1.2);
}

.preset-card .card-name {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-primary);
  display: block;
}

.preset-card .card-desc {
  font-size: 0.72rem;
  color: var(--text-secondary);
  margin-top: 4px;
  display: block;
  line-height: 1.3;
}

/* ========================================
   Step Navigation
   ======================================== */
.step-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 32px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

.export-buttons {
  display: flex;
  gap: 10px;
}

/* ========================================
   Form Elements (Step 2)
   ======================================== */
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 24px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group-full {
  grid-column: 1 / -1;
}

.form-label {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-primary);
}

.range-value {
  color: var(--accent);
  font-weight: 700;
  font-size: 1.1rem;
}

/* Range Slider */
.form-range {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}

.form-range::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--accent);
  border-radius: 50%;
  cursor: pointer;
  transition: box-shadow var(--transition);
}

.form-range::-webkit-slider-thumb:hover {
  box-shadow: 0 0 0 6px var(--accent-glow);
}

.form-range::-moz-range-thumb {
  width: 20px;
  height: 20px;
  background: var(--accent);
  border: none;
  border-radius: 50%;
  cursor: pointer;
}

.range-limits {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* Select */
.form-select {
  padding: 10px 14px;
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 0.9rem;
  cursor: pointer;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg width='10' height='6' viewBox='0 0 10 6' fill='none' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='M1 1L5 5L9 1' stroke='%23a0a0b0' stroke-width='1.5' stroke-linecap='round'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
}

.form-select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

/* Input */
.form-input {
  padding: 10px 14px;
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 0.9rem;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition);
  width: 100%;
}

.form-input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

/* Textarea */
.form-textarea {
  padding: 12px 14px;
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 0.9rem;
  outline: none;
  resize: vertical;
  transition: border-color var(--transition), box-shadow var(--transition);
  width: 100%;
  line-height: 1.6;
}

.form-textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

.form-textarea-lg {
  min-height: 200px;
}

/* Radio Buttons */
.radio-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.radio-label {
  display: flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
}

.radio-label:hover {
  background: var(--bg-surface);
}

.form-radio {
  display: none;
}

.radio-custom {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  border: 2px solid var(--border);
  position: relative;
  transition: border-color var(--transition);
  flex-shrink: 0;
}

.radio-custom::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%) scale(0);
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  transition: transform var(--transition);
}

.form-radio:checked + .radio-custom {
  border-color: var(--accent);
}

.form-radio:checked + .radio-custom::after {
  transform: translate(-50%, -50%) scale(1);
}

.radio-text {
  font-size: 0.9rem;
  color: var(--text-primary);
}

/* ========================================
   Step 3: Input Area
   ======================================== */
.input-area {
  margin-bottom: 8px;
}

.input-area.hidden {
  display: none;
}

/* AI mode tabs */
.ai-input-tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--border);
  padding-bottom: 2px;
}

.ai-tab {
  background: none;
  border: none;
  color: var(--text-secondary);
  padding: 10px 16px;
  font-size: 0.9rem;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  transition: all var(--transition);
  position: relative;
  bottom: -2px;
}

.ai-tab:hover {
  color: var(--text-primary);
  background: rgba(0, 212, 170, 0.05);
}

.ai-tab.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
  font-weight: 500;
}

.ai-input-panel.hidden {
  display: none;
}

.file-upload-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-top: 12px;
}

.btn-upload {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.file-name {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.btn-generate {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 1rem;
  padding: 12px 28px;
}

/* ========================================
   Step 4: Editor Split Pane
   ======================================== */
.editor-split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  min-height: 400px;
  margin-bottom: 8px;
}

.editor-pane,
.preview-pane {
  display: flex;
  flex-direction: column;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.editor-pane-header {
  padding: 10px 16px;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.editor-textarea {
  flex: 1;
  border: none;
  border-radius: 0;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.7;
  resize: none;
  min-height: 360px;
}

.editor-textarea:focus {
  box-shadow: none;
}

.preview-content {
  flex: 1;
  padding: 16px;
  overflow-y: auto;
}

.preview-placeholder {
  color: var(--text-secondary);
  font-size: 0.9rem;
  text-align: center;
  margin-top: 80px;
}

/* Preview slide cards */
.preview-slide {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  margin-bottom: 12px;
}

.preview-slide-title {
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 6px;
  color: var(--accent);
}

.preview-slide-body {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Outline Editor Pane */
.outline-editor-pane,
.yaml-preview-pane {
  display: flex;
  flex-direction: column;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
}

.outline-editor {
  flex: 1;
  padding: 16px;
  overflow-y: auto;
  min-height: 360px;
}

.editor-placeholder {
  color: var(--text-secondary);
  font-size: 0.9rem;
  text-align: center;
  margin-top: 80px;
}

/* YAML Preview Pane */
.yaml-preview-textarea {
  flex: 1;
  border: none;
  border-radius: 0;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  line-height: 1.7;
  resize: none;
  min-height: 360px;
  background: var(--bg-card);
  color: var(--text-primary);
}

.yaml-preview-textarea:focus {
  box-shadow: none;
  outline: none;
}

/* Copy Button in Header */
.editor-pane-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.btn-copy {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font-size: 0.75rem;
  background: var(--accent);
  color: var(--bg-primary);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: opacity 0.2s ease;
  font-weight: 500;
}

.btn-copy:hover {
  opacity: 0.85;
}

.btn-copy svg {
  flex-shrink: 0;
}

/* Responsive */
@media (max-width: 1024px) {
  .editor-split {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .outline-editor,
  .yaml-preview-textarea {
    min-height: 300px;
  }
}

/* ========================================
   Outline Editor Cards
   ======================================== */
.outline-card {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  transition: box-shadow 0.2s ease;
}

.outline-card:hover {
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.outline-card:last-child {
  margin-bottom: 0;
}

.outline-card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--border);
  border-radius: var(--radius-md) var(--radius-md) 0 0;
}

.outline-card-number {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.outline-card-body {
  padding: 16px;
}

.outline-field-label {
  display: block;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 6px;
  margin-top: 12px;
}

.outline-field-label:first-child {
  margin-top: 0;
}

.outline-field-input,
.outline-field-textarea {
  width: 100%;
  padding: 10px 12px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.9rem;
  font-family: inherit;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.outline-field-input:focus,
.outline-field-textarea:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(0, 212, 170, 0.1);
}

.outline-field-textarea {
  resize: vertical;
  min-height: 80px;
  line-height: 1.6;
  font-family: var(--font-mono);
}

.outline-field-secondary {
  min-height: 50px;
  font-size: 0.85rem;
  opacity: 0.85;
  background: rgba(255, 255, 255, 0.02);
}

/* Responsive */
@media (max-width: 768px) {
  .outline-card-header {
    padding: 10px 12px;
  }

  .outline-card-body {
    padding: 12px;
  }

  .outline-field-input,
  .outline-field-textarea {
    font-size: 0.85rem;
  }
}

/* ========================================
   PDF Panel
   ======================================== */
.pdf-dropzone {
  border: 2px dashed var(--border);
  border-radius: var(--radius);
  padding: 48px 24px;
  text-align: center;
  transition: all var(--transition);
  cursor: pointer;
}

.pdf-dropzone:hover,
.pdf-dropzone.drag-over {
  border-color: var(--accent);
  background: rgba(0, 212, 170, 0.04);
}

.pdf-dropzone.drag-over {
  transform: scale(1.01);
}

.dropzone-icon {
  color: var(--text-secondary);
  margin-bottom: 12px;
  transition: color var(--transition);
}

.pdf-dropzone:hover .dropzone-icon {
  color: var(--accent);
}

.dropzone-text {
  font-size: 1rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
}

/* Progress */
.pdf-progress {
  margin-top: 24px;
}

.pdf-progress.hidden {
  display: none;
}

.progress-bar-track {
  width: 100%;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 3px;
  width: 0%;
  transition: width 0.4s ease;
}

.progress-text {
  display: block;
  font-size: 0.8rem;
  color: var(--text-secondary);
  margin-top: 8px;
  text-align: center;
}

/* Results */
.pdf-results {
  margin-top: 24px;
}

.pdf-results.hidden {
  display: none;
}

.pdf-results-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 16px;
}

.pdf-results-header h3 {
  font-size: 1rem;
  font-weight: 600;
}

.pdf-results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: 12px;
}

.pdf-result-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  overflow: hidden;
  transition: transform var(--transition);
}

.pdf-result-item:hover {
  transform: translateY(-2px);
}

.pdf-result-item img {
  width: 100%;
  display: block;
}

.pdf-result-item .pdf-page-label {
  padding: 8px;
  text-align: center;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

/* ========================================
   Buttons
   ======================================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 20px;
  border: none;
  border-radius: var(--radius-sm);
  font-family: var(--font);
  font-size: 0.9rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  line-height: 1;
}

.btn-primary {
  background: var(--accent);
  color: var(--bg-primary);
}

.btn-primary:hover {
  background: var(--accent-hover);
  box-shadow: 0 4px 16px var(--accent-glow);
}

.btn-secondary {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}

.btn-secondary:hover {
  background: rgba(0, 212, 170, 0.08);
}

.btn-sm {
  padding: 7px 14px;
  font-size: 0.82rem;
}

.btn:disabled,
.btn.disabled {
  opacity: 0.5;
  cursor: not-allowed;
  pointer-events: none;
}

/* ========================================
   Modal
   ======================================== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  backdrop-filter: blur(4px);
  animation: fadeIn 0.2s ease;
}

.modal-overlay.hidden {
  display: none;
}

.modal-box {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 32px;
  width: 90%;
  max-width: 440px;
  animation: slideDown 0.3s ease;
}

.modal-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.modal-desc {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 20px;
  line-height: 1.5;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 10px;
  margin-top: 20px;
}

/* ========================================
   Modal 通用樣式（更新）
   ======================================== */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  padding: 20px;
}

.modal.hidden {
  display: none;
}

.modal-content {
  background: var(--bg-surface);
  border-radius: var(--radius-lg);
  max-width: 500px;
  width: 100%;
  max-height: 90vh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
}

.help-modal-content {
  max-width: 900px;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
}

.modal-header h2 {
  margin: 0;
  font-size: 1.25rem;
  color: var(--text-primary);
}

.btn-close {
  background: none;
  border: none;
  font-size: 2rem;
  color: var(--text-secondary);
  cursor: pointer;
  padding: 0;
  line-height: 1;
  transition: color var(--transition);
}

.btn-close:hover {
  color: var(--text-primary);
}

.modal-body {
  padding: 24px;
  overflow-y: auto;
  flex: 1;
}

.modal-footer {
  padding: 16px 24px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: flex-end;
  gap: 12px;
}

/* ========================================
   使用說明彈窗
   ======================================== */
.help-section {
  margin-bottom: 32px;
}

.help-section:last-child {
  margin-bottom: 0;
}

.help-section h3 {
  font-size: 1.1rem;
  color: var(--accent);
  margin-bottom: 16px;
}

.help-section h4 {
  font-size: 1rem;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.help-section p {
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 12px;
}

.help-section ol,
.help-section ul {
  color: var(--text-secondary);
  line-height: 1.8;
  padding-left: 24px;
}

.help-section a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition);
}

.help-section a:hover {
  border-bottom-color: var(--accent);
}

/* 四步驟流程圖 */
.help-steps {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  margin: 20px 0;
  flex-wrap: wrap;
}

.help-step {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  flex: 1;
  min-width: 100px;
}

.help-step-icon {
  font-size: 2rem;
  width: 60px;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-primary);
  border-radius: 50%;
  border: 2px solid var(--border);
}

.help-step-title {
  font-size: 0.85rem;
  color: var(--text-secondary);
  text-align: center;
}

.help-step-arrow {
  color: var(--text-secondary);
  font-size: 1.5rem;
  flex-shrink: 0;
}

/* 模式說明卡片 */
.help-mode {
  background: var(--bg-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 16px;
  margin-bottom: 16px;
}

.help-mode:last-child {
  margin-bottom: 0;
}

.help-mode h4 {
  margin-top: 0;
}

/* 響應式 */
@media (max-width: 768px) {
  .help-steps {
    flex-direction: column;
  }

  .help-step-arrow {
    transform: rotate(90deg);
  }
}

/* ========================================
   NotebookLM Guide
   ======================================== */
.notebooklm-guide {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  margin: 24px 0;
}

.notebooklm-guide-title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0 0 20px 0;
  text-align: center;
}

.notebooklm-steps {
  display: flex;
  gap: 20px;
  align-items: flex-start;
}

.notebooklm-step {
  flex: 1;
  display: flex;
  gap: 12px;
  align-items: flex-start;
}

.notebooklm-step-number {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  background: var(--accent);
  color: var(--bg-primary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.95rem;
}

.notebooklm-step-content {
  flex: 1;
}

.notebooklm-step-content strong {
  display: block;
  color: var(--text-primary);
  margin-bottom: 6px;
  font-size: 0.95rem;
}

.notebooklm-step-content p {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.85rem;
  line-height: 1.5;
}

.notebooklm-step-content a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s ease;
}

.notebooklm-step-content a:hover {
  border-bottom-color: var(--accent);
}

/* 響應式 */
@media (max-width: 1024px) {
  .notebooklm-steps {
    flex-direction: column;
    gap: 16px;
  }
}

/* ========================================
   Toast
   ======================================== */
.toast-container {
  position: fixed;
  top: 20px;
  right: 20px;
  z-index: 2000;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
}

.toast {
  background: var(--bg-surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 20px;
  font-size: 0.88rem;
  color: var(--text-primary);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
  pointer-events: auto;
  animation: slideInRight 0.35s ease;
  display: flex;
  align-items: center;
  gap: 8px;
  max-width: 360px;
}

.toast.toast-success {
  border-left: 3px solid var(--success);
}

.toast.toast-error {
  border-left: 3px solid var(--danger);
}

.toast.toast-info {
  border-left: 3px solid var(--info);
}

.toast.toast-hide {
  animation: slideOutRight 0.3s ease forwards;
}

/* ========================================
   Loading Overlay
   ======================================== */
.loading-overlay {
  position: fixed;
  inset: 0;
  background: rgba(10, 10, 15, 0.85);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 3000;
  backdrop-filter: blur(6px);
}

.loading-overlay.hidden {
  display: none;
}

.spinner {
  width: 44px;
  height: 44px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.loading-text {
  margin-top: 16px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* ========================================
   Footer
   ======================================== */
.app-footer {
  text-align: center;
  padding: 20px 24px;
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--text-secondary);
}

/* ========================================
   Animations
   ======================================== */
@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(80px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideOutRight {
  from {
    opacity: 1;
    transform: translateX(0);
  }
  to {
    opacity: 0;
    transform: translateX(80px);
  }
}

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

/* ========================================
   Scrollbar
   ======================================== */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}

/* ========================================
   Responsive (max-width: 768px)
   ======================================== */
@media (max-width: 768px) {
  .app-header {
    padding: 14px 16px;
  }

  .header-brand {
    flex-direction: column;
    gap: 2px;
  }

  .header-title {
    font-size: 1.15rem;
  }

  .header-logo {
    height: 24px;
  }

  .btn-api-key span {
    display: none;
  }

  .app-main {
    padding: 16px 12px 32px;
  }

  .mode-tab {
    font-size: 0.82rem;
    padding: 10px 8px;
  }

  .step-progress {
    padding: 0 8px;
  }

  .step-dot {
    width: 28px;
    height: 28px;
    font-size: 0.7rem;
  }

  .step-label {
    font-size: 0.65rem;
  }

  .step-line {
    min-width: 16px;
  }

  .card-grid {
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 8px;
  }

  .preset-card {
    padding: 12px 8px;
  }

  .preset-card .card-emoji {
    font-size: 1.4rem;
  }

  .preset-card .card-name {
    font-size: 0.78rem;
  }

  .preset-card .card-desc {
    display: none;
  }

  .form-grid {
    grid-template-columns: 1fr;
  }

  .editor-split {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .editor-textarea {
    min-height: 200px;
  }

  .step-nav {
    flex-wrap: wrap;
    gap: 10px;
  }

  .export-buttons {
    flex-wrap: wrap;
  }

  .pdf-results-grid {
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  }

  .modal-box {
    padding: 20px;
    margin: 0 12px;
  }

  .toast {
    max-width: 300px;
  }
}