/**
 * Lecture Mind - Student Playground Component Library
 *
 * BEM components with `sp-` prefix. All colors/spacing via CSS custom properties.
 *
 * Storage mapping: flashcard status -> --new/--learning/--review/--mastered (FLASHCARD_STATUS),
 * quality buttons -> --fail(0-2)/--hard(3)/--good(4)/--easy(5) (SM-2),
 * sync indicator -> --online/--offline/--syncing (SYNC_STATUS),
 * progress ring -> watchProgress (0-100), confusion btn -> --voted
 */

/* ============================================
   FLASHCARD COMPONENT
   ============================================ */
.sp-flashcard {
  perspective: var(--perspective-card);
  width: 100%;
  max-width: 480px;
  aspect-ratio: 3 / 2;
  cursor: pointer;
}

.sp-flashcard__inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform var(--duration-medium) var(--ease-out);
}

.sp-flashcard--flipped .sp-flashcard__inner {
  transform: rotateY(180deg);
}

.sp-flashcard__front,
.sp-flashcard__back {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-6);
  border-radius: var(--radius-xl);
  overflow: hidden;
  text-align: center;
}

.sp-flashcard__front {
  background: var(--surface);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-3d-front);
  color: var(--foreground);
}

.sp-flashcard__back {
  background: var(--surface-elevated);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-3d-back);
  color: var(--foreground);
  transform: rotateY(180deg);
}

/* Flashcard active flip lift */
.sp-flashcard:active .sp-flashcard__inner {
  will-change: transform;
}

/* Flashcard status borders (left accent strip) */
.sp-flashcard--new .sp-flashcard__front {
  border-left: 3px solid var(--color-mastery-new);
}

.sp-flashcard--learning .sp-flashcard__front {
  border-left: 3px solid var(--color-mastery-learning);
}

.sp-flashcard--review .sp-flashcard__front {
  border-left: 3px solid var(--color-mastery-review);
}

.sp-flashcard--known .sp-flashcard__front {
  border-left: 3px solid var(--color-mastery-known);
}

.sp-flashcard--mastered .sp-flashcard__front {
  border-left: 3px solid var(--color-mastery-mastered);
}

/* Dark mode */
.dark .sp-flashcard__front {
  background: var(--surface);
  box-shadow: var(--shadow-3d-front);
}

.dark .sp-flashcard__back {
  background: var(--surface-elevated);
  box-shadow: var(--shadow-3d-back);
}

/* ============================================
   PROGRESS RING (SVG-based circular progress)
   ============================================ */
.sp-progress-ring {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.sp-progress-ring__circle {
  fill: none;
  stroke: var(--color-primary-500);
  stroke-width: 4;
  stroke-linecap: round;
  transform: rotate(-90deg);
  transform-origin: center;
  transition: stroke-dashoffset var(--duration-large) var(--ease-out);
}

.sp-progress-ring__bg {
  fill: none;
  stroke: var(--border-subtle);
  stroke-width: 4;
}

.sp-progress-ring__value {
  position: absolute;
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--foreground);
}

.dark .sp-progress-ring__circle {
  stroke: var(--color-primary-400);
}

.dark .sp-progress-ring__bg {
  stroke: var(--color-neutral-700);
}

/* ============================================
   LIBRARY CARD (Lecture grid item)
   ============================================ */
.sp-library-card {
  display: flex;
  flex-direction: column;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  cursor: pointer;
  transition: transform var(--duration-normal) var(--ease-out),
              box-shadow var(--duration-normal) var(--ease-out);
}

.sp-library-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.sp-library-card:focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: 2px;
}

.sp-library-card__thumbnail {
  aspect-ratio: 16 / 9;
  background: var(--background-subtle);
  overflow: hidden;
}

.sp-library-card__thumbnail img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.sp-library-card__meta {
  padding: var(--space-4);
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  flex: 1;
}

.sp-library-card__title {
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  color: var(--foreground);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.sp-library-card__progress {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  color: var(--foreground-muted);
}

.sp-library-card__progress-bar {
  flex: 1;
  height: 4px;
  background: var(--border-subtle);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.sp-library-card__progress-fill {
  height: 100%;
  background: var(--color-primary-500);
  border-radius: var(--radius-full);
  transition: width var(--duration-slow) var(--ease-out);
}

.dark .sp-library-card {
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

.dark .sp-library-card:hover {
  box-shadow: var(--shadow-lg), var(--shadow-glow-sm);
}

.dark .sp-library-card__progress-fill {
  background: var(--color-primary-400);
}

.sp-library-card__course {
  display: inline-block;
  font-size: 0.75rem;
  padding: 0.125rem 0.5rem;
  border-radius: 9999px;
  background: var(--color-primary-100, #e0e7ff);
  color: var(--color-primary-700, #4338ca);
}

.dark .sp-library-card__course {
  background: var(--color-primary-900, #312e81);
  color: var(--color-primary-200, #c7d2fe);
}

.sp-sentinel {
  height: 1px;
  width: 100%;
}

/* ============================================
   STUDY CONTROLS (Quality buttons for SM-2)
   ============================================ */
.sp-study-controls {
  display: flex;
  gap: var(--space-2);
  justify-content: center;
  flex-wrap: wrap;
}

.sp-study-controls__quality-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--foreground);
  cursor: pointer;
  transition: background-color var(--duration-fast) var(--ease-out),
              border-color var(--duration-fast) var(--ease-out),
              transform var(--duration-fast) var(--ease-out);
}

.sp-study-controls__quality-btn:hover {
  transform: translateY(-1px);
}

.sp-study-controls__quality-btn:active {
  transform: translateY(0);
}

/* Fail (quality 0-2) - Rose */
.sp-study-controls__quality-btn--fail {
  border-color: var(--color-error-400);
  color: var(--color-error-500);
}

.sp-study-controls__quality-btn--fail:hover {
  background: var(--error-bg);
}

/* Hard (quality 3) - Amber */
.sp-study-controls__quality-btn--hard {
  border-color: var(--color-warning-400);
  color: var(--color-warning-500);
}

.sp-study-controls__quality-btn--hard:hover {
  background: var(--warning-bg);
}

/* Good (quality 4) - Primary */
.sp-study-controls__quality-btn--good {
  border-color: var(--color-primary-400);
  color: var(--color-primary-500);
}

.sp-study-controls__quality-btn--good:hover {
  background: var(--primary-bg);
}

/* Easy (quality 5) - Emerald */
.sp-study-controls__quality-btn--easy {
  border-color: var(--color-success-400);
  color: var(--color-success-500);
}

.sp-study-controls__quality-btn--easy:hover {
  background: var(--success-bg);
}

/* Dark mode button adjustments */
.dark .sp-study-controls__quality-btn {
  background: var(--surface);
  border-color: var(--border);
}

/* ============================================
   CONFUSION VOTE BUTTON + HEATMAP
   ============================================ */
.sp-confusion-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--foreground-muted);
  cursor: pointer;
  transition: background-color var(--duration-fast) var(--ease-out),
              border-color var(--duration-fast) var(--ease-out),
              color var(--duration-fast) var(--ease-out);
}

.sp-confusion-btn:hover {
  border-color: var(--color-confusion-medium);
  color: var(--color-confusion-medium);
}

.sp-confusion-btn--voted {
  background: var(--color-confusion-medium-bg);
  border-color: var(--color-confusion-medium);
  color: var(--color-confusion-medium);
}

/* Confusion heatmap bar */
.sp-confusion-heatmap {
  height: 4px;
  border-radius: var(--radius-full);
  background: linear-gradient(
    90deg,
    var(--color-confusion-low) 0%,
    var(--color-confusion-medium) 33%,
    var(--color-confusion-high) 66%,
    var(--color-confusion-critical) 100%
  );
  opacity: 0.6;
}

.dark .sp-confusion-btn {
  background: var(--surface);
}

.dark .sp-confusion-btn--voted {
  background: var(--color-confusion-medium-bg);
}

/* ============================================
   MASTERY BADGE
   ============================================ */
.sp-mastery-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-0_5) var(--space-2);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  letter-spacing: var(--tracking-wide);
  text-transform: uppercase;
}

.sp-mastery-badge--new {
  background: var(--color-mastery-new-bg);
  color: var(--color-mastery-new);
}

.sp-mastery-badge--learning {
  background: var(--color-mastery-learning-bg);
  color: var(--color-mastery-learning);
}

.sp-mastery-badge--review {
  background: var(--color-mastery-review-bg);
  color: var(--color-mastery-review);
}

.sp-mastery-badge--known {
  background: var(--color-mastery-known-bg);
  color: var(--color-mastery-known);
}

.sp-mastery-badge--mastered {
  background: var(--color-mastery-mastered-bg);
  color: var(--color-mastery-mastered);
}

/* Dark mode: mastery colors auto-adjust via tokens-v2.css custom properties */

/* ============================================
   SYNC INDICATOR
   ============================================ */
.sp-sync-indicator {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  background: var(--surface);
  border: 1px solid var(--border);
}

.sp-sync-indicator__dot {
  width: 8px;
  height: 8px;
  border-radius: var(--radius-full);
  flex-shrink: 0;
}

/* Online - Emerald dot */
.sp-sync-indicator--online .sp-sync-indicator__dot {
  background: var(--color-success-500);
}

.sp-sync-indicator--online {
  color: var(--color-success-500);
  border-color: var(--color-success-400);
}

/* Offline - Slate dot */
.sp-sync-indicator--offline .sp-sync-indicator__dot {
  background: var(--color-neutral-400);
}

.sp-sync-indicator--offline {
  color: var(--foreground-muted);
  border-color: var(--border);
}

/* Syncing - Primary dot with pulse */
.sp-sync-indicator--syncing .sp-sync-indicator__dot {
  background: var(--color-primary-500);
  animation: pulse 1.5s var(--ease-in-out) infinite;
}

.sp-sync-indicator--syncing {
  color: var(--color-primary-500);
  border-color: var(--color-primary-400);
}

/* Dark mode */
.dark .sp-sync-indicator {
  background: var(--surface);
}

.dark .sp-sync-indicator--online .sp-sync-indicator__dot {
  background: var(--color-success-400);
}

.dark .sp-sync-indicator--syncing .sp-sync-indicator__dot {
  background: var(--color-primary-400);
}

/* ============================================
   ACTIVE NAV LINK (Playground router)
   ============================================ */
.nav-link--active {
  color: var(--color-primary-500);
  font-weight: var(--font-semibold);
  border-bottom: 2px solid var(--color-primary-500);
}

.dark .nav-link--active {
  color: var(--color-primary-400);
  border-bottom-color: var(--color-primary-400);
}

/* ============================================================================
   Library Layout (Week 12)
   ============================================================================ */

.sp-library-layout { display: flex; gap: var(--space-6); }
.sp-library-sidebar { width: 240px; flex-shrink: 0; }
.sp-library-main { flex: 1; min-width: 0; }
.sp-library-toolbar { display: flex; justify-content: space-between; align-items: center; margin-bottom: var(--space-4); }

/* Sidebar Items */
.sp-library-sidebar__item {
  display: flex; align-items: center; gap: var(--space-2);
  padding: var(--space-2) var(--space-3); border-radius: var(--radius-md);
  cursor: pointer; font-size: var(--text-sm); color: var(--foreground);
  transition: background-color var(--duration-fast) var(--ease-out);
  background: none; border: none; width: 100%; text-align: left;
}
.sp-library-sidebar__item:hover { background: var(--background-subtle); }
.sp-library-sidebar__item:focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: -2px;
}
.sp-library-sidebar__item--active,
.sp-library-sidebar__item[aria-current="true"] {
  background: var(--primary-bg, rgba(34, 211, 238, 0.1));
  color: var(--color-primary-500); font-weight: var(--font-semibold);
}
.sp-library-sidebar__color-dot {
  width: 10px; height: 10px; border-radius: var(--radius-full); flex-shrink: 0;
}
.sp-library-sidebar__count {
  margin-left: auto; font-size: var(--text-xs); color: var(--foreground-muted);
}

/* Toolbar */
.sp-library-toolbar__sort {
  padding: var(--space-1) var(--space-2); border-radius: var(--radius-md);
  border: 1px solid var(--border-color, #334155); background: var(--background);
  color: var(--foreground); font-size: var(--text-sm);
}
.sp-library-toolbar__view-toggle { display: flex; gap: var(--space-1); }
.sp-library-toolbar__btn {
  padding: var(--space-1) var(--space-2); border-radius: var(--radius-md);
  border: 1px solid var(--border-color, #334155); background: none;
  color: var(--foreground); cursor: pointer; font-size: var(--text-sm);
}
.sp-library-toolbar__btn:focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: 2px;
}
.sp-library-toolbar__btn[aria-pressed="true"] {
  background: var(--primary-bg, rgba(34, 211, 238, 0.1));
  color: var(--color-primary-500);
}

/* Dialog */
.sp-dialog-overlay {
  position: fixed; inset: 0; background: rgba(0, 0, 0, 0.5);
  display: flex; align-items: center; justify-content: center; z-index: 100;
}
.sp-dialog {
  background: var(--background, #0f172a); border-radius: var(--radius-lg);
  padding: var(--space-6); max-width: 480px; width: 90%;
  border: 1px solid var(--border-color, #334155);
}
.sp-dialog-title { margin: 0 0 var(--space-4); font-size: var(--text-lg); color: var(--foreground); }
.sp-dialog-label { display: block; margin-bottom: var(--space-1); font-size: var(--text-sm); color: var(--foreground-muted); }
.sp-dialog-input {
  width: 100%; padding: var(--space-2); border-radius: var(--radius-md);
  border: 1px solid var(--border-color, #334155); background: var(--background-subtle, #1e293b);
  color: var(--foreground); font-size: var(--text-sm); margin-bottom: var(--space-3);
}
.sp-dialog-color-row { display: flex; gap: var(--space-2); margin-bottom: var(--space-3); }
.sp-dialog-color-swatch {
  width: 32px; height: 32px; border-radius: var(--radius-full); border: 2px solid transparent;
  cursor: pointer; padding: 0;
}
.sp-dialog-color-swatch--active { border-color: var(--foreground); }
.sp-dialog-error { color: var(--color-error, #ef4444); font-size: var(--text-sm); min-height: 1.2em; margin-bottom: var(--space-2); }
.sp-dialog-buttons { display: flex; gap: var(--space-2); justify-content: flex-end; }
.sp-dialog-btn {
  padding: var(--space-2) var(--space-4); border-radius: var(--radius-md);
  border: 1px solid var(--border-color, #334155); background: none;
  color: var(--foreground); cursor: pointer; font-size: var(--text-sm);
}
.sp-dialog-btn--primary {
  background: var(--color-primary-500); color: white; border-color: var(--color-primary-500);
}

/* Responsive: collapse sidebar below 768px */
@media (max-width: 768px) {
  .sp-library-layout { flex-direction: column; }
  .sp-library-sidebar {
    width: 100%;
    display: flex;
    gap: var(--space-2);
    overflow-x: auto;
    padding-bottom: var(--space-2);
    -webkit-overflow-scrolling: touch;
  }
  .sp-library-sidebar__item { white-space: nowrap; flex-shrink: 0; }
  .sp-library-toolbar { flex-wrap: wrap; gap: var(--space-2); }
  .sp-card-grid { grid-template-columns: 1fr; }
  .sp-dashboard { padding: var(--space-2); }
  .sp-dashboard__header { flex-wrap: wrap; gap: var(--space-2); }
  .sp-results-table { font-size: var(--text-xs); }
  .sp-results-table td,
  .sp-results-table th { padding: var(--space-2); }
  .sp-detail-stats { flex-wrap: wrap; gap: var(--space-2); }
  .sp-detail-tabs [role="tablist"] { overflow-x: auto; -webkit-overflow-scrolling: touch; }
  .sp-detail-tabs [role="tab"] { white-space: nowrap; flex-shrink: 0; }
}

/* Forced-colors override */
@media (forced-colors: active) {
  .sp-library-sidebar__item--active { border: 1px solid Highlight; }
  .sp-library-sidebar__color-dot { forced-color-adjust: none; }
}

/* ============================================
   CROSS-LECTURE SEARCH (Day 3)
   ============================================ */
.sp-search-input-wrapper {
  position: relative;
  margin-bottom: var(--space-4);
}
.sp-search-input-wrapper input {
  width: 100%;
  padding: var(--space-2) var(--space-10) var(--space-2) var(--space-3);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  background: var(--background);
  color: var(--foreground);
  transition: border-color var(--duration-fast) var(--ease-out),
              box-shadow var(--duration-fast) var(--ease-out);
}
.sp-search-input-wrapper input:focus {
  outline: none;
  border-color: var(--color-primary-500);
  box-shadow: 0 0 0 3px rgba(34, 211, 238, 0.15);
}
.sp-search-input-wrapper__clear {
  position: absolute;
  right: var(--space-2);
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  cursor: pointer;
  color: var(--foreground-muted);
  font-size: var(--text-sm);
  padding: var(--space-1);
}

.sp-search-tabs {
  display: flex;
  gap: var(--space-1);
  border-bottom: 1px solid var(--border);
  margin-bottom: var(--space-4);
}
.sp-search-tabs__tab {
  padding: var(--space-2) var(--space-4);
  cursor: pointer;
  border: none;
  border-bottom: 2px solid transparent;
  background: none;
  font-size: var(--text-sm);
  color: var(--foreground-muted);
  transition: color var(--duration-fast) var(--ease-out),
              border-color var(--duration-fast) var(--ease-out);
}
.sp-search-tabs__tab:hover {
  color: var(--foreground);
}
.sp-search-tabs__tab:focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: -2px;
}
.sp-search-tabs__tab--active,
.sp-search-tabs__tab[aria-selected="true"] {
  border-bottom-color: var(--color-primary-500);
  font-weight: var(--font-semibold);
  color: var(--color-primary-500);
}

.sp-search-result {
  padding: var(--space-4);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-2);
  cursor: pointer;
}
.sp-search-result:hover {
  background: var(--background-subtle);
}
.sp-search-result__lecture {
  font-size: var(--text-xs);
  color: var(--foreground-muted);
}
.sp-search-result__type {
  display: inline-block;
  padding: var(--space-0_5) var(--space-2);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: var(--font-medium);
  background: var(--background-subtle);
}

.sp-search-highlight {
  background: var(--color-warning-100, rgba(245, 158, 11, 0.2));
  border-radius: 2px;
  padding: 0 1px;
}

.dark .sp-search-highlight {
  background: rgba(245, 158, 11, 0.15);
}

@media (forced-colors: active) {
  .sp-search-highlight { background: Highlight; color: HighlightText; }
}

/* ============================================================================
   Day 4: Detail View
   ============================================================================ */

.sp-detail-back {
  background: none;
  border: none;
  color: var(--color-primary-500);
  cursor: pointer;
  font-size: var(--text-sm);
  padding: var(--space-2) 0;
  margin-bottom: var(--space-2);
}

.sp-detail-back:hover { text-decoration: underline; }

.sp-detail-title {
  font-size: var(--text-2xl);
  font-weight: var(--font-bold);
  margin: 0 0 var(--space-2) 0;
}

.sp-detail-stats {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin: var(--space-4) 0;
}

.sp-detail-stat {
  flex: 1;
  min-width: 120px;
  padding: var(--space-4);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-align: center;
}

.sp-detail-stat__value {
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
}

.sp-detail-stat__label {
  font-size: var(--text-xs);
  color: var(--foreground-muted);
}

.sp-detail-tabs {
  display: flex;
  border-bottom: 2px solid var(--border);
  margin: var(--space-4) 0 var(--space-2);
}

.sp-detail-tabs__tab {
  background: none;
  border: none;
  border-bottom: 2px solid transparent;
  padding: var(--space-2) var(--space-4);
  cursor: pointer;
  color: var(--foreground-muted);
  font-size: var(--text-sm);
  margin-bottom: -2px;
  transition: color var(--duration-fast) var(--ease-out),
              border-color var(--duration-fast) var(--ease-out);
}

.sp-detail-tabs__tab:hover {
  color: var(--foreground);
}

.sp-detail-tabs__tab[aria-selected="true"] {
  color: var(--color-primary-500);
  border-bottom-color: var(--color-primary-500);
  font-weight: var(--font-semibold);
}

.sp-detail-tabs__tab:focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: -2px;
}

.sp-segment-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3);
  border-bottom: 1px solid var(--border-subtle);
}

.sp-segment-item--completed { opacity: 0.6; }

.sp-segment-item__check { width: 1.5em; text-align: center; }
.sp-segment-item__time { font-size: var(--text-sm); color: var(--foreground-muted); white-space: nowrap; }
.sp-segment-item__type { font-size: var(--text-xs); background: var(--surface); padding: 2px 6px; border-radius: var(--radius-sm); }
.sp-segment-item__text { font-size: var(--text-sm); flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.sp-segment-item__confused-btn {
  font-size: var(--text-xs);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
  background: var(--surface);
  color: var(--foreground-muted);
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.15s, color 0.15s;
}
.sp-segment-item__confused-btn:hover,
.sp-segment-item__confused-btn:focus-visible {
  background: var(--surface-hover, var(--surface));
  outline: 2px solid var(--ring, currentColor);
  outline-offset: 1px;
}
.sp-segment-item__confused-btn--active {
  background: var(--warning-bg, #fef3c7);
  color: var(--warning-text, #92400e);
  border-color: var(--warning-border, #f59e0b);
}

.sp-flashcard-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3);
  border-bottom: 1px solid var(--border-subtle);
}

.sp-flashcard-item__front { flex: 1; }
.sp-flashcard-item__status { font-size: var(--text-xs); background: var(--surface); padding: 2px 6px; border-radius: var(--radius-sm); }
.sp-flashcard-item__actions { display: flex; gap: var(--space-2); }

.sp-bookmark-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3);
  border-bottom: 1px solid var(--border-subtle);
}

.sp-bookmark-item__time { font-size: var(--text-sm); color: var(--foreground-muted); white-space: nowrap; }
.sp-bookmark-item__label { flex: 1; }

.sp-lecture-info { padding: var(--space-4); }
.sp-lecture-info__item { margin: var(--space-2) 0; color: var(--foreground-muted); }

.sp-course-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  color: white;
}

.sp-empty-state {
  text-align: center;
  color: var(--foreground-muted);
  padding: var(--space-8) var(--space-4);
  font-size: var(--text-sm);
}

.sp-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-2) var(--space-4);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  cursor: pointer;
  background: var(--surface);
}

.sp-btn--primary {
  background: var(--color-primary-500);
  color: white;
  border-color: var(--color-primary-500);
}

.sp-btn--primary:hover {
  opacity: 0.9;
}

/* ============================================================================
   Day 5: Playlist + Favorites
   ============================================================================ */

.sp-playlist-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-4);
  border-top: 1px solid var(--border);
  margin-top: var(--space-6);
}

.sp-playlist-nav__btn {
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-2) var(--space-3);
  cursor: pointer;
  font-size: var(--text-sm);
  color: var(--foreground);
  max-width: 40%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sp-playlist-nav__btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.sp-playlist-nav__btn:not(:disabled):hover {
  background: var(--surface);
}

.sp-playlist-nav__btn:focus-visible {
  outline: 2px solid var(--color-primary-500);
  outline-offset: 2px;
}

.sp-playlist-nav__position {
  font-size: var(--text-sm);
  color: var(--foreground-muted);
}

.sp-playlist-minimap {
  display: flex;
  gap: var(--space-2);
  justify-content: center;
  padding: var(--space-3);
  overflow-x: auto;
  max-width: 100%;
}

.sp-playlist-minimap__dot {
  width: 10px;
  height: 10px;
  border-radius: var(--radius-full);
  border: 2px solid var(--border);
  cursor: pointer;
  padding: 0;
  background: transparent;
}

.sp-playlist-minimap__dot--current {
  background: var(--color-primary-500);
  border-color: var(--color-primary-500);
}

.sp-playlist-minimap__dot--completed {
  background: var(--color-success-500);
  border-color: var(--color-success-500);
}

.sp-favorite-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1.25rem;
  padding: var(--space-1);
  transition: transform 0.1s ease;
}

.sp-favorite-btn--active {
  color: var(--color-warning-500);
}

.sp-favorite-btn:hover {
  transform: scale(1.1);
}

@media (forced-colors: active) {
  .sp-favorite-btn--active { forced-color-adjust: none; color: Highlight; }
  .sp-playlist-minimap__dot--current { forced-color-adjust: none; }
}

/* ============================================
   DASHBOARD LAYOUT
   ============================================ */
.sp-dashboard {
  max-width: 960px;
  margin: 0 auto;
  padding: var(--space-4);
}

.sp-dashboard__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  margin-bottom: var(--space-6);
}

.sp-dashboard__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-6);
}

.sp-dashboard__card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: var(--space-5);
}

/* Analytics section (chart wrapper) — streak card styles are in analytics.css */
.sp-analytics-section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: var(--space-5);
  margin-bottom: var(--space-6);
}

.sp-analytics-section h3 {
  margin: 0 0 var(--space-4);
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  padding-bottom: var(--space-2);
  border-bottom: 2px solid var(--color-primary-500);
}

/* Results table — row hover highlighting */
.sp-results-table {
  width: 100%;
  border-collapse: collapse;
}

.sp-results-table th {
  text-align: left;
  padding: var(--space-3) var(--space-4);
  border-bottom: 2px solid var(--border);
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--foreground-muted);
}

.sp-results-table td {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--border-subtle);
  font-size: var(--text-sm);
}

.sp-results-table tbody tr {
  transition: background-color var(--duration-fast) var(--ease-out);
}

.sp-results-table tbody tr:hover {
  background: var(--background-subtle);
}

/* ============================================
   TOUCH TARGET + REDUCED MOTION
   ============================================ */

/* Enlarge minimap dots for touch on mobile */
@media (max-width: 768px) {
  .sp-playlist-minimap__dot {
    width: 24px;
    height: 24px;
  }
}

/* Respect prefers-reduced-motion */
@media (prefers-reduced-motion: reduce) {
  .sp-flashcard__inner,
  .sp-library-card,
  .sp-study-controls__quality-btn,
  .sp-confusion-btn,
  .sp-detail-tabs__tab,
  .sp-favorite-btn,
  .sp-results-table tbody tr,
  .sp-heatmap__bar {
    transition: none;
  }

  .sp-sync-indicator--syncing .sp-sync-indicator__dot {
    animation: none;
  }

  .sp-library-card:hover {
    transform: none;
  }

  .sp-study-controls__quality-btn:hover,
  .sp-study-controls__quality-btn:active {
    transform: none;
  }
}

/* ============================================
   W16 Day 1: Confusion Heatmap Bar Chart
   ============================================ */

.sp-heatmap {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  width: 100%;
}

.sp-heatmap__row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.sp-heatmap__label {
  flex: 0 0 30%;
  min-width: 80px;
  font-size: 0.875rem;
  color: var(--foreground);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.sp-heatmap__bar-wrapper {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  height: 1.5rem;
  background: var(--background-subtle, #f1f5f9);
  border-radius: var(--radius-sm, 4px);
  overflow: hidden;
  position: relative;
}

.sp-heatmap__bar {
  height: 100%;
  border-radius: var(--radius-sm, 4px);
  transition: width 0.3s ease;
  min-width: 2px;
}

.sp-heatmap__count {
  position: absolute;
  right: 0.5rem;
  z-index: 1;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--foreground);
  font-variant-numeric: tabular-nums;
  background: rgba(255, 255, 255, 0.85);
  padding: 0 0.25rem;
  border-radius: 2px;
}

@media (min-width: 768px) {
  .sp-heatmap__label {
    flex: 0 0 25%;
  }
}

/* Confusion Summary Stats */

.sp-confusion-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 1rem;
  padding: 0.75rem;
  background: var(--background-subtle, #f1f5f9);
  border-radius: var(--radius, 8px);
}

.sp-confusion-stats__item {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  min-width: 120px;
}

.sp-confusion-stats__label {
  font-size: 0.75rem;
  color: var(--foreground-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.sp-confusion-stats__value {
  font-size: 1rem;
  font-weight: 600;
  color: var(--foreground);
}

/* Dark mode overrides for heatmap + stats */
.dark .sp-heatmap__bar-wrapper {
  background: var(--background-subtle, #1e293b);
}

.dark .sp-heatmap__count {
  background: rgba(0, 0, 0, 0.7);
  color: var(--foreground, #f1f5f9);
}

.dark .sp-confusion-stats {
  background: var(--background-subtle, #1e293b);
}