/**
 * ============================================================================
 * FLASHCARD SYSTEM STYLES
 * ============================================================================
 *
 * Follows patterns from subject-materials.css
 * Uses CSS custom properties for theme consistency
 *
 * ============================================================================
 */

/* ============================================
   FLASHCARDS VIEW (Content Area Container)
   ============================================ */
.flashcards-view {
  padding: var(--spacing-lg, 2rem);
  max-width: 800px;
  margin: 0 auto;
  animation: flashcardFadeIn 0.3s ease;
}

@keyframes flashcardFadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ============================================
   FLASHCARD PANE (Orchestrator)
   ============================================ */
.flashcard-pane {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg, 1.5rem);
}

.flashcard-pane__header {
  text-align: center;
  padding-bottom: var(--spacing-md, 1rem);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.flashcard-pane__title-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--spacing-md, 1rem);
  flex-wrap: wrap;
}

.flashcard-pane__title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text-light, #f9fafb);
  margin: 0;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.flashcard-pane__title i {
  color: var(--primary-color, #e81123);
}

.flashcard-pane__count-badge {
  display: inline-flex;
  padding: 0.3rem 0.75rem;
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-muted, #9ca3af);
  border-radius: var(--radius-sm, 6px);
  font-size: 0.8rem;
  font-weight: 500;
}

.flashcard-pane__context {
  font-size: 0.95rem;
  color: var(--text-muted, #9ca3af);
  margin: 0.5rem 0 0;
}

.flashcard-pane__topic-indicator {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.85rem;
  background: rgba(232, 17, 35, 0.1);
  color: var(--text-light, #e5e7eb);
  border-radius: var(--radius-sm, 8px);
  font-size: 0.85rem;
  border: 1px solid rgba(232, 17, 35, 0.3);
  margin-top: 0.75rem;
}

.flashcard-pane__topic-indicator i {
  color: var(--primary-color, #e81123);
}

.flashcard-pane__topic-indicator strong {
  color: var(--primary-color, #e81123);
}

/* ============================================
   TOPIC SELECTOR
   ============================================ */
.flashcard-topic-selector {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm, 0.5rem);
  padding: var(--spacing-sm, 0.5rem) 0;
}

.flashcard-topic-selector__label {
  font-size: 0.9rem;
  color: var(--text-muted, #9ca3af);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.flashcard-topic-selector__select {
  padding: 0.5rem 2.5rem 0.5rem 1rem;
  background: var(--background-alt);
  color: var(--text-light, #f9fafb);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-sm, 6px);
  font-size: var(--font-size-base);
  font-family: var(--font-family);
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%239ca3af' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  background-size: 12px;
  min-width: 200px;
  transition:
    border-color 0.2s ease,
    box-shadow 0.2s ease;
}

.flashcard-topic-selector__select:hover {
  border-color: rgba(255, 255, 255, 0.25);
}

.flashcard-topic-selector__select:focus {
  outline: none;
  border-color: var(--primary-color, #e81123);
}

.flashcard-topic-selector__select optgroup {
  background: #1f2937;
  color: var(--text-muted, #9ca3af);
  font-weight: 600;
  top: 3rem;
}

.flashcard-topic-selector__select option {
  background: #1f2937;
  color: var(--text-light, #f9fafb);
  padding: 0.5rem;
}

/* ============================================
   FLASHCARD CARD (with 3D flip animation)
   ============================================ */
.flashcard-card-container {
  perspective: 1000px;
  width: 100%;
  min-height: 350px;
}

.flashcard-card {
  position: relative;
  width: 100%;
  height: 350px;
  cursor: pointer;
  transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

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

.flashcard-card__front,
.flashcard-card__back {
  position: absolute;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: var(--spacing-xl, 2rem);
  background: var(--background-alt, rgba(255, 255, 255, 0.05));
  border-radius: var(--radius-lg, 16px);
  border: 1px solid rgba(255, 255, 255, 0.1);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
  overflow: hidden;
}

.flashcard-card__front {
  background: linear-gradient(
    145deg,
    rgba(232, 17, 35, 0.08) 0%,
    rgba(255, 255, 255, 0.03) 100%
  );
  border-color: rgba(232, 17, 35, 0.2);
}

.flashcard-card__back {
  transform: rotateY(180deg);
  background: linear-gradient(
    145deg,
    rgba(59, 130, 246, 0.08) 0%,
    rgba(255, 255, 255, 0.03) 100%
  );
  border-color: rgba(59, 130, 246, 0.2);
}

.flashcard-card:hover {
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
}

.flashcard-card:hover .flashcard-card__front,
.flashcard-card:hover .flashcard-card__back {
  border-color: rgba(255, 255, 255, 0.2);
}

.flashcard-card__content {
  text-align: center;
  max-width: 100%;
  max-height: 100%;
  overflow-y: auto;
  padding: 0 0.5rem;
}

.flashcard-card__content::-webkit-scrollbar {
  width: 4px;
}

.flashcard-card__content::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.05);
  border-radius: 2px;
}

.flashcard-card__content::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.2);
  border-radius: 2px;
}

.flashcard-card__text {
  font-size: 1.15rem;
  line-height: 1.7;
  color: var(--text-light, #f9fafb);
  margin: 0;
}

.flashcard-card__content--front .flashcard-card__text {
  font-size: 1.35rem;
  font-weight: 600;
}

.flashcard-card__image {
  max-width: 100%;
  max-height: 180px;
  border-radius: var(--radius-sm, 8px);
  margin-bottom: 1rem;
  object-fit: contain;
}

.flashcard-card__caption {
  font-size: 0.95rem;
  color: var(--text-muted, #9ca3af);
  font-style: italic;
  margin: 0.5rem 0 0;
}

.flashcard-card__key-points {
  list-style: none;
  padding: 0;
  margin: 1.25rem 0 0;
  text-align: left;
  width: 100%;
}

.flashcard-card__key-points li {
  padding: 0.5rem 0;
  padding-left: 1.5rem;
  position: relative;
  color: var(--text-light, #e5e7eb);
  font-size: 0.95rem;
  line-height: 1.5;
}

.flashcard-card__key-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.85rem;
  width: 8px;
  height: 8px;
  background: var(--primary-color, #e81123);
  border-radius: 50%;
}

.flashcard-card__support-image {
  max-width: 60%;
  max-height: 100px;
  border-radius: var(--radius-sm, 6px);
  margin-top: 1rem;
  object-fit: contain;
}

.flashcard-card__flip-hint {
  position: absolute;
  bottom: 1rem;
  font-size: 0.8rem;
  color: var(--text-muted, #9ca3af);
  display: flex;
  align-items: center;
  gap: 0.4rem;
  opacity: 0.6;
  transition: opacity 0.2s ease;
}

.flashcard-card:hover .flashcard-card__flip-hint {
  opacity: 1;
}

.flashcard-card__flip-hint i {
  font-size: 0.75rem;
}

.flashcard-card__difficulty {
  position: absolute;
  top: 1rem;
  right: 1rem;
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-sm, 4px);
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.flashcard-card__difficulty--easy {
  background: rgba(34, 197, 94, 0.2);
  color: #22c55e;
}

.flashcard-card__difficulty--medium {
  background: rgba(234, 179, 8, 0.2);
  color: #eab308;
}

.flashcard-card__difficulty--hard {
  background: rgba(239, 68, 68, 0.2);
  color: #ef4444;
}

/* ============================================
   PROGRESS INDICATOR
   ============================================ */
.flashcard-progress {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.flashcard-progress__text {
  font-size: 0.9rem;
  color: var(--text-muted, #9ca3af);
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.flashcard-progress__current {
  font-weight: 700;
  color: var(--primary-color, #e81123);
  font-size: 1.1rem;
}

.flashcard-progress__separator {
  color: var(--text-muted, #6b7280);
}

.flashcard-progress__total {
  font-weight: 500;
}

.flashcard-progress__topic {
  color: var(--text-muted, #6b7280);
  font-size: 0.85rem;
  margin-left: 0.25rem;
}

.flashcard-progress__bar-container {
  width: 100%;
  max-width: 300px;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
  overflow: hidden;
}

.flashcard-progress__bar {
  height: 100%;
  background: linear-gradient(90deg, var(--primary-color, #e81123), #ff4d5a);
  border-radius: 3px;
  transition: width 0.3s ease;
}

/* ============================================
   NAVIGATION CONTROLS
   ============================================ */
.flashcard-nav {
  display: flex;
  justify-content: center;
  gap: var(--spacing-md, 1rem);
  padding-top: var(--spacing-md, 1rem);
}

.flashcard-nav__btn {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-sm, 8px);
  font-size: 0.95rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
  border: none;
  font-family: inherit;
}

.flashcard-nav__prev,
.flashcard-nav__next {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-light, #e5e7eb);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.flashcard-nav__prev:hover:not(:disabled),
.flashcard-nav__next:hover:not(:disabled) {
  background: rgba(255, 255, 255, 0.12);
  border-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.flashcard-nav__shuffle {
  background: var(--primary-color, #e81123);
  color: white;
}

.flashcard-nav__shuffle:hover {
  background: var(--primary-hover, #c70f1f);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(232, 17, 35, 0.4);
}

.flashcard-nav__btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
  transform: none !important;
}

.flashcard-nav__btn:active:not(:disabled) {
  transform: translateY(0);
}

/* ============================================
   KEYBOARD HINT
   ============================================ */
.flashcard-keyboard-hint {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  padding-top: 0.5rem;
  opacity: 0.5;
  font-size: 0.75rem;
  color: var(--text-muted, #9ca3af);
}

.flashcard-keyboard-hint span {
  display: flex;
  align-items: center;
  gap: 0.3rem;
}

.flashcard-keyboard-hint kbd {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 22px;
  height: 22px;
  padding: 0 6px;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: 4px;
  font-family: inherit;
  font-size: 0.7rem;
}

/* ============================================
   EMPTY & ERROR STATES
   ============================================ */
.flashcards-empty-state,
.flashcards-error-state {
  text-align: center;
  padding: 4rem 2rem;
  color: var(--text-muted, #9ca3af);
}

.flashcards-empty-state i,
.flashcards-error-state i {
  font-size: 4rem;
  margin-bottom: 1.5rem;
  opacity: 0.4;
  display: block;
}

.flashcards-empty-state h3 {
  font-size: 1.25rem;
  color: var(--text-light, #f9fafb);
  margin: 0 0 0.5rem;
  font-weight: 600;
}

.flashcards-empty-state p,
.flashcards-error-state p {
  margin: 0.5rem 0;
  font-size: 0.95rem;
  line-height: 1.6;
}

.flashcards-error-state i {
  color: var(--primary-color, #e81123);
}

/* ============================================
   MOBILE RESPONSIVE
   ============================================ */
@media (max-width: 768px) {
  .flashcards-view {
    padding: var(--spacing-md, 1rem);
  }

  .flashcard-pane__title {
    font-size: 1.25rem;
  }

  .flashcard-card-container {
    min-height: 300px;
  }

  .flashcard-card {
    height: 300px;
  }

  .flashcard-card__front,
  .flashcard-card__back {
    padding: var(--spacing-lg, 1.5rem);
  }

  .flashcard-card__text {
    font-size: 1rem;
  }

  .flashcard-card__content--front .flashcard-card__text {
    font-size: 1.15rem;
  }

  .flashcard-card__key-points li {
    font-size: 0.9rem;
  }

  .flashcard-nav {
    flex-wrap: wrap;
    gap: 0.75rem;
  }

  .flashcard-nav__btn {
    padding: 0.6rem 1rem;
    font-size: 0.85rem;
  }

  .flashcard-topic-selector {
    flex-direction: column;
    gap: 0.5rem;
  }

  .flashcard-topic-selector__select {
    width: 100%;
    min-width: unset;
  }

  .flashcard-keyboard-hint {
    display: none;
  }
}

@media (max-width: 480px) {
  .flashcard-card-container {
    min-height: 280px;
  }

  .flashcard-card {
    height: 280px;
  }

  .flashcard-card__front,
  .flashcard-card__back {
    padding: 1.25rem;
  }

  .flashcard-pane__title-row {
    flex-direction: column;
    gap: 0.5rem;
  }
}

/* ============================================
   LIGHT MODE SUPPORT
   ============================================ */
[data-theme="light"] .flashcard-pane__header {
  border-bottom-color: rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .flashcard-pane__title {
  color: var(--text-dark, #1f2937);
}

[data-theme="light"] .flashcard-pane__context {
  color: var(--text-muted-light, #6b7280);
}

[data-theme="light"] .flashcard-card__front,
[data-theme="light"] .flashcard-card__back {
  background: #ffffff;
  border-color: rgba(0, 0, 0, 0.1);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
}

[data-theme="light"] .flashcard-card__front {
  background: linear-gradient(145deg, rgba(232, 17, 35, 0.05) 0%, #ffffff 100%);
}

[data-theme="light"] .flashcard-card__back {
  background: linear-gradient(
    145deg,
    rgba(59, 130, 246, 0.05) 0%,
    #ffffff 100%
  );
}

[data-theme="light"] .flashcard-card__text {
  color: var(--text-dark, #1f2937);
}

[data-theme="light"] .flashcard-card__key-points li {
  color: var(--text-dark, #374151);
}

[data-theme="light"] .flashcard-nav__prev,
[data-theme="light"] .flashcard-nav__next {
  background: rgba(0, 0, 0, 0.05);
  color: var(--text-dark, #1f2937);
  border-color: rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .flashcard-nav__prev:hover:not(:disabled),
[data-theme="light"] .flashcard-nav__next:hover:not(:disabled) {
  background: rgba(0, 0, 0, 0.08);
  border-color: rgba(0, 0, 0, 0.15);
}

[data-theme="light"] .flashcard-topic-selector__select {
  background-color: #ffffff;
  color: var(--text-dark, #1f2937);
  border-color: rgba(0, 0, 0, 0.15);
}

[data-theme="light"] .flashcard-topic-selector__select optgroup,
[data-theme="light"] .flashcard-topic-selector__select option {
  background: #ffffff;
  color: var(--text-dark, #1f2937);
}

[data-theme="light"] .flashcard-progress__bar-container {
  background: rgba(0, 0, 0, 0.1);
}

[data-theme="light"] .flashcards-empty-state,
[data-theme="light"] .flashcards-error-state {
  color: var(--text-muted-light, #6b7280);
}

[data-theme="light"] .flashcards-empty-state h3 {
  color: var(--text-dark, #1f2937);
}