/* ==========================================================================
   CCNA 200-301 Drag and Drop Module Stylesheet (dnd.css)
   Inherits design system and color tokens from style.css
   ========================================================================== */

/* Main DND Workbench Layout */
.dnd-container {
  max-width: 1300px;
  margin: 0 auto;
  padding: 1.5rem 1rem 4rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Category Filter Bar */
.category-filter-bar {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  overflow-x: auto;
  padding: 0.25rem 0 0.5rem;
  scrollbar-width: thin;
}

.category-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 0.9rem;
  border-radius: 9999px;
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s ease;
}

.category-pill:hover {
  background: var(--bg-surface-hover);
  color: var(--text-primary);
  border-color: var(--accent-cisco);
}

.category-pill.active {
  background: var(--accent-cisco);
  color: #ffffff;
  border-color: var(--accent-cisco);
  box-shadow: 0 4px 12px var(--accent-cisco-glow);
}

/* Question Header Card */
.dnd-question-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.dnd-question-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.meta-badges {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.badge-q-number {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  color: var(--accent-cisco);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.9rem;
}

.badge-q-category {
  background: rgba(14, 165, 233, 0.12);
  border: 1px solid rgba(14, 165, 233, 0.3);
  color: var(--accent-cisco-hover);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  font-weight: 600;
}

.meta-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.btn-meta {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.4rem 0.8rem;
  border-radius: var(--radius-sm);
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-meta:hover {
  background: var(--bg-surface-hover);
  color: var(--text-primary);
  border-color: var(--accent-cisco);
}

.btn-meta.btn-bookmark.active {
  background: var(--status-review-bg);
  border-color: var(--status-review);
  color: var(--status-review);
}

.btn-meta.btn-master.active {
  background: var(--status-mastered-bg);
  border-color: var(--status-mastered);
  color: var(--status-mastered);
}

.btn-exhibit {
  background: linear-gradient(135deg, rgba(14, 165, 233, 0.2), rgba(56, 189, 248, 0.1));
  border: 1px solid var(--accent-cisco);
  color: #38bdf8;
  font-weight: 700;
}

.btn-exhibit:hover {
  background: var(--accent-cisco);
  color: #ffffff;
}

/* Question Prompts */
.dnd-question-title {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.4;
  margin: 0;
}

.dnd-prompt-en {
  font-size: 1rem;
  color: var(--text-primary);
  line-height: 1.5;
  background: var(--bg-surface-elevated);
  padding: 0.85rem 1rem;
  border-left: 4px solid var(--accent-cisco);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.dnd-prompt-vi {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.5;
  font-style: italic;
  padding-left: 0.5rem;
}

/* Inline Exhibit for Question Cards */
.dnd-inline-exhibit {
  margin-top: 0.75rem;
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.inline-exhibit-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.55rem 0.85rem;
  background: rgba(255, 255, 255, 0.03);
  border-bottom: 1px solid var(--border-color);
}

.inline-exhibit-title {
  font-size: 0.86rem;
  font-weight: 700;
  color: var(--accent-cisco-hover);
  display: flex;
  align-items: center;
  gap: 0.35rem;
}

.btn-zoom-exhibit {
  background: rgba(14, 165, 233, 0.1);
  border: 1px solid rgba(14, 165, 233, 0.3);
  color: var(--accent-cisco-hover);
  font-size: 0.76rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-zoom-exhibit:hover {
  background: var(--accent-cisco);
  color: #fff;
}

.inline-exhibit-img-wrap {
  padding: 0.6rem;
  display: flex;
  justify-content: center;
  align-items: center;
  background: #ffffff;
  cursor: zoom-in;
}

.inline-exhibit-img {
  max-width: 100%;
  max-height: 420px;
  object-fit: contain;
  border-radius: 4px;
}

/* Touch Selection Notice Banner */
.selection-notice-banner {
  background: rgba(14, 165, 233, 0.15);
  border: 1px dashed var(--accent-cisco);
  color: #38bdf8;
  padding: 0.65rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: space-between;
  animation: pulse-notice 1.5s infinite alternate;
}

@keyframes pulse-notice {
  0% { box-shadow: 0 0 0 rgba(14, 165, 233, 0); }
  100% { box-shadow: 0 0 12px var(--accent-cisco-glow); }
}

/* Workspace Grid: Source Pool vs Drop Zones */
.dnd-workbench {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  align-items: start;
}

@media (max-width: 900px) {
  .dnd-workbench {
    grid-template-columns: 1fr;
  }
}

/* Workbench Column Boxes */
.workbench-column {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  box-shadow: var(--shadow-card);
}

.column-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.75rem;
}

.column-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.column-hint {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* Source Pool Items Container */
.source-items-pool {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  min-height: 250px;
}

.pool-empty-notice {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 200px;
  color: var(--text-muted);
  font-style: italic;
  border: 1px dashed var(--border-color);
  border-radius: var(--radius-md);
  padding: 1rem;
  text-align: center;
}

/* Draggable Item Styles */
.draggable-item {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.75rem 0.9rem;
  cursor: grab;
  cursor: -webkit-grab;
  user-select: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease, background-color 0.15s ease;
  position: relative;
}

.draggable-item:hover {
  background: var(--bg-surface-hover);
  border-color: var(--accent-cisco);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.draggable-item:active,
.draggable-item.dragging {
  cursor: grabbing;
  cursor: -webkit-grabbing;
  opacity: 0.5;
  transform: scale(0.98);
  border-color: var(--accent-cisco);
}

.draggable-item.selected {
  border-color: var(--accent-cisco);
  background: rgba(14, 165, 233, 0.12);
  box-shadow: 0 0 0 2px var(--accent-cisco), 0 0 16px var(--accent-cisco-glow);
  transform: scale(1.02);
}

.draggable-item.item-correct {
  border-color: var(--status-mastered) !important;
  background: var(--status-mastered-bg) !important;
}

.draggable-item.item-correct::before {
  content: '✓';
  color: var(--status-mastered);
  font-weight: 800;
  font-size: 1rem;
  margin-right: 0.35rem;
}

.draggable-item.item-incorrect {
  border-color: var(--status-danger) !important;
  background: var(--status-danger-bg) !important;
}

.draggable-item.item-incorrect::before {
  content: '✕';
  color: var(--status-danger);
  font-weight: 800;
  font-size: 1rem;
  margin-right: 0.35rem;
}

.draggable-item.is-distractor {
  opacity: 0.6;
  border-style: dashed !important;
  border-color: #f59e0b !important;
  background: rgba(245, 158, 11, 0.06) !important;
  cursor: not-allowed !important;
}

.distractor-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.72rem;
  font-weight: 700;
  color: #f59e0b;
  background: rgba(245, 158, 11, 0.12);
  border: 1px solid rgba(245, 158, 11, 0.35);
  border-radius: 4px;
  padding: 2px 6px;
  margin-top: 0.35rem;
  align-self: flex-start;
}

.item-content {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
  flex: 1;
}

.item-text-en {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.45;
  font-family: var(--font-main);
}

.item-text-vi {
  display: none;
}

.btn-remove-item {
  background: transparent;
  border: none;
  color: var(--text-muted);
  width: 24px;
  height: 24px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 0.85rem;
  transition: all 0.2s ease;
  flex-shrink: 0;
}

.btn-remove-item:hover {
  background: rgba(239, 68, 68, 0.2);
  color: #ef4444;
}

/* Drop Zones Container */
.drop-zones-container {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.drop-zone {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.85rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  transition: all 0.2s ease;
}

.drop-zone.zone-correct {
  border-color: var(--status-mastered);
  background: rgba(16, 185, 129, 0.05);
}

.drop-zone.zone-incorrect {
  border-color: var(--status-danger);
  background: rgba(239, 68, 68, 0.05);
}

.zone-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  border-bottom: 1px dashed rgba(255, 255, 255, 0.08);
  padding-bottom: 0.4rem;
}

.zone-count-badge {
  font-size: 0.74rem;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 9999px;
  background: rgba(14, 165, 233, 0.12);
  color: var(--accent-cisco-hover);
  border: 1px solid rgba(14, 165, 233, 0.3);
  white-space: nowrap;
  letter-spacing: 0.02em;
  transition: all 0.2s ease;
}

.zone-count-badge.count-filled {
  background: rgba(16, 185, 129, 0.15);
  color: #10b981;
  border-color: rgba(16, 185, 129, 0.4);
}

.zone-label-vi {
  display: none;
}

.zone-label-en {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--accent-cisco-hover);
  line-height: 1.4;
}

.zone-slots {
  min-height: 54px;
  border: 2px dashed var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.4rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  transition: all 0.2s ease;
}

.zone-slots.drag-over {
  border-color: var(--accent-cisco);
  background: rgba(14, 165, 233, 0.1);
  border-style: solid;
}

.slot-placeholder {
  color: var(--text-muted);
  font-size: 0.82rem;
  font-style: italic;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  text-align: center;
}

/* Bottom Action Bar */
.dnd-action-bar {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
  box-shadow: var(--shadow-card);
}

.action-bar-left,
.action-bar-right {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.btn-action {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.6rem 1.1rem;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s ease;
  border: 1px solid transparent;
}

.btn-action.btn-nav {
  background: var(--bg-surface-elevated);
  border-color: var(--border-color);
  color: var(--text-primary);
}

.btn-action.btn-nav:hover:not(:disabled) {
  background: var(--bg-surface-hover);
  border-color: var(--accent-cisco);
}

.btn-action.btn-nav:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.btn-action.btn-reset {
  background: var(--bg-surface-elevated);
  border-color: var(--border-color);
  color: var(--text-secondary);
}

.btn-action.btn-reset:hover {
  background: var(--bg-surface-hover);
  color: var(--text-primary);
}

.btn-action.btn-reset-all {
  background: rgba(239, 68, 68, 0.1);
  border-color: rgba(239, 68, 68, 0.35);
  color: #ef4444;
}

.btn-action.btn-reset-all:hover {
  background: rgba(239, 68, 68, 0.22);
  border-color: #ef4444;
  color: #ffffff;
  transform: translateY(-1px);
}

.btn-action.btn-check {
  background: var(--accent-cisco);
  color: #ffffff;
  box-shadow: 0 4px 14px var(--accent-cisco-glow);
}

.btn-action.btn-check:hover {
  background: var(--accent-cisco-hover);
  transform: translateY(-1px);
}

.btn-action.btn-show {
  background: linear-gradient(135deg, rgba(16, 185, 129, 0.2), rgba(52, 211, 153, 0.1));
  border-color: var(--status-mastered);
  color: #34d399;
}

.btn-action.btn-show:hover {
  background: var(--status-mastered);
  color: #ffffff;
}

.btn-action.btn-toggle-dump {
  background: var(--bg-surface-elevated);
  border-color: var(--border-color);
  color: var(--text-secondary);
}

.btn-action.btn-toggle-dump:hover {
  color: var(--text-primary);
  border-color: var(--accent-cisco);
}

/* Explanation & Dump Image Cards */
.dnd-explanation-card,
.dnd-dump-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  box-shadow: var(--shadow-card);
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.explanation-header,
.dump-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-color);
  padding-bottom: 0.75rem;
}

.explanation-title,
.dump-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--status-mastered);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.dump-title {
  color: var(--accent-cisco);
}

.explanation-content {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--text-primary);
}

.explanation-content p {
  margin-bottom: 0.6rem;
}

.explanation-content ul {
  padding-left: 1.25rem;
  margin-bottom: 0.75rem;
}

.explanation-content li {
  margin-bottom: 0.4rem;
}

.dump-image-viewer {
  display: flex;
  justify-content: center;
  align-items: center;
  background: #000000;
  border-radius: var(--radius-md);
  padding: 1rem;
  overflow: auto;
}

.dump-image-viewer img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.6);
}

/* Sidebar Questions Grid */
.dnd-sidebar-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 0.5rem;
  padding: 1rem;
  overflow-y: auto;
}

.q-badge-btn {
  aspect-ratio: 1;
  border-radius: var(--radius-sm);
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-family: var(--font-mono);
  font-size: 0.88rem;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.15s ease;
  position: relative;
}

.q-badge-btn:hover {
  background: var(--bg-surface-hover);
  color: var(--text-primary);
  border-color: var(--accent-cisco);
  transform: scale(1.05);
}

.q-badge-btn.current {
  border-color: var(--accent-cisco);
  color: #ffffff;
  box-shadow: 0 0 0 2px var(--accent-cisco);
}

.q-badge-btn.correct {
  background: var(--status-mastered-bg);
  border-color: var(--status-mastered);
  color: var(--status-mastered);
}

.q-badge-btn.incorrect {
  background: var(--status-danger-bg);
  border-color: var(--status-danger);
  color: var(--status-danger);
}

.q-badge-btn.mastered {
  background: var(--status-mastered);
  color: #ffffff;
}

.q-badge-btn.in-progress {
  border-style: dashed;
}

.q-badge-btn.bookmarked::after {
  content: '★';
  position: absolute;
  top: 2px;
  right: 2px;
  color: var(--status-review);
  font-size: 0.65rem;
}

/* Modal Lightbox */
.dnd-modal {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.85);
  backdrop-filter: blur(8px);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.dnd-modal.hidden {
  display: none !important;
}

.modal-content {
  background: var(--bg-surface);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  max-width: 900px;
  width: 100%;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.7);
  overflow: hidden;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 1.25rem;
  border-bottom: 1px solid var(--border-color);
}

.modal-title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.modal-close-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  font-size: 1.4rem;
  cursor: pointer;
  padding: 0.2rem 0.5rem;
  border-radius: var(--radius-sm);
}

.modal-close-btn:hover {
  color: var(--text-primary);
  background: var(--bg-surface-hover);
}

.modal-body {
  padding: 1.25rem;
  overflow: auto;
  display: flex;
  justify-content: center;
  align-items: center;
  background: #050811;
}

.modal-body img {
  max-width: 100%;
  height: auto;
  border-radius: var(--radius-sm);
}

/* Utility Helpers */
.hidden {
  display: none !important;
}

/* Link Tab in Header */
.mode-tabs .btn-dnd-tab {
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}