/**
 * EB-003: PDF Toolkit Styles
 * Refined, responsive, accessible workspace.
 */

/* Main Container */
.tool-main {
  max-width: var(--container-tool);
  margin: 0 auto;
  padding: var(--space-8) var(--space-4) var(--space-16);
  width: 100%;
}

/* Tool Hero */
.tool-hero {
  margin-bottom: var(--space-6);
  max-width: 640px;
}

.tool-title {
  font-size: 1.875rem;
  font-weight: 700;
  letter-spacing: -0.025em;
  color: var(--text-primary);
  margin: 0 0 var(--space-2);
  line-height: 1.3;
}

.tool-description {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin: 0;
}

/* ==========================================================================
   Mode Switcher Tabs
   ========================================================================== */
.mode-tabs {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  border-bottom: 1px solid var(--border-default);
  margin-bottom: var(--space-6);
  overflow-x: auto;
  scrollbar-width: none;
}

.mode-tabs::-webkit-scrollbar {
  display: none;
}

.mode-tab {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  color: var(--text-secondary);
  font-size: 0.9375rem;
  font-weight: 500;
  padding: var(--space-3) var(--space-4);
  cursor: pointer;
  white-space: nowrap;
  transition: color var(--dur-fast) var(--ease), border-color var(--dur-fast) var(--ease);
  margin-bottom: -1px;
}

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

.mode-tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
  font-weight: 600;
}

.mode-tab:focus-visible {
  outline: none;
  border-radius: var(--radius-xs);
  box-shadow: var(--focus-ring);
}

/* ==========================================================================
   Upload Dropzone
   ========================================================================== */
.dropzone {
  border: 2px dashed var(--border-default);
  border-radius: var(--radius-md);
  padding: var(--space-10) var(--space-6);
  text-align: center;
  background-color: var(--bg-surface);
  cursor: pointer;
  transition: border-color var(--dur-fast) var(--ease), background-color var(--dur-fast) var(--ease);
  outline: none;
  margin-bottom: var(--space-6);
}

.dropzone:hover,
.dropzone:focus-visible,
.dropzone.dragover {
  border-color: var(--color-primary);
  background-color: var(--color-primary-subtle);
}

.dropzone-icon {
  width: 44px;
  height: 44px;
  color: var(--text-muted);
  margin: 0 auto var(--space-3);
  display: flex;
  align-items: center;
  justify-content: center;
}

.dropzone-title {
  font-size: 1.0625rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0 0 var(--space-1);
}

.dropzone-hint {
  font-size: 0.875rem;
  color: var(--text-muted);
  margin: 0 0 var(--space-3);
}

/* ==========================================================================
   Mode Workspaces
   ========================================================================== */
.mode-panel {
  display: none;
  flex-direction: column;
  gap: var(--space-5);
}

.mode-panel.active {
  display: flex;
}

.workspace-card {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  padding: var(--space-5);
  box-shadow: var(--shadow-sm);
}

.card-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-4);
  flex-wrap: wrap;
  gap: var(--space-2);
}

.card-heading {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin: 0;
}

/* Merge Files List */
.merge-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.merge-item {
  display: grid;
  grid-template-columns: 32px 1fr auto auto;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3);
  background-color: var(--bg-page);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
  transition: border-color var(--dur-fast) var(--ease);
}

.merge-item:hover {
  border-color: var(--border-default);
}

.item-index {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-muted);
  text-align: center;
}

.item-name {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.item-meta {
  font-size: 0.75rem;
  color: var(--text-muted);
}

.item-actions {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

/* Organize Pages Grid */
.pages-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: var(--space-3);
  max-height: 480px;
  overflow-y: auto;
  padding: var(--space-2);
  background-color: var(--bg-page);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-sm);
}

.page-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  padding: var(--space-2);
  transition: all var(--dur-fast) var(--ease);
  position: relative;
}

.page-card.deleted {
  opacity: 0.4;
  border-style: dashed;
}

.page-visual {
  width: 90px;
  height: 120px;
  background-color: #ffffff;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-xs);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 1.125rem;
  font-weight: 700;
  transition: transform var(--dur-normal) var(--ease);
  margin-bottom: var(--space-2);
}

.page-footer-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding-top: var(--space-1);
  border-top: 1px solid var(--border-subtle);
}

.page-num {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.page-tools {
  display: flex;
  align-items: center;
  gap: 2px;
}

.icon-btn {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 3px;
  border-radius: var(--radius-xs);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: color var(--dur-fast) var(--ease), background-color var(--dur-fast) var(--ease);
}

.icon-btn:hover {
  color: var(--text-primary);
  background-color: var(--bg-subtle);
}

/* Split Range Input */
.range-input-wrap {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.range-input {
  width: 100%;
  height: 42px;
  padding: 0 var(--space-3);
  font-size: 0.9375rem;
  font-family: inherit;
  background-color: var(--bg-surface);
  color: var(--text-primary);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color var(--dur-fast) var(--ease), box-shadow var(--dur-fast) var(--ease);
}

.range-input:focus {
  border-color: var(--color-primary);
  box-shadow: var(--focus-ring);
}

.range-hint {
  font-size: 0.8125rem;
  color: var(--text-muted);
}

/* Result / Status Card */
.result-banner {
  display: none;
  align-items: center;
  justify-content: space-between;
  background-color: var(--color-success-subtle);
  border: 1px solid var(--color-success);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  margin-top: var(--space-4);
}

.result-message {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-success);
}

/* FAQ Section */
.faq-section {
  margin-top: var(--space-16);
  padding-top: var(--space-8);
  border-top: 1px solid var(--border-default);
}

.faq-title {
  font-size: 1.375rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin: 0 0 var(--space-2);
}

.faq-subtitle {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin: 0 0 var(--space-6);
}

.faq-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-width: 820px;
}

.faq-item {
  background-color: var(--bg-surface);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  padding: var(--space-4);
  cursor: pointer;
  transition: border-color var(--dur-fast) var(--ease);
}

.faq-item:hover {
  border-color: var(--border-hover);
}

.faq-summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--text-primary);
  list-style: none;
  user-select: none;
}

.faq-summary::-webkit-details-marker {
  display: none;
}

.faq-chevron {
  width: 16px;
  height: 16px;
  color: var(--text-muted);
  transition: transform var(--dur-normal) var(--ease);
  flex-shrink: 0;
  margin-left: var(--space-2);
}

details[open] .faq-chevron {
  transform: rotate(180deg);
}

.faq-body {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin: var(--space-3) 0 0;
}