.interactive-flashcard-container {
  --flashcard-white: #fff;
  --flashcard-success: #10b981;
  --flashcard-danger: #ef4444;

  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
  width: 100%;
  box-sizing: border-box;
  color: var(--text-color, #1e293b);
  background: var(--card-bg, #fff);
  border-radius: 1rem;
  padding: 1.5rem;
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
  border: 1px solid var(--border-color, #e2e8f0);
  animation: flashcard-tool-enter 0.45s ease;
}

.theme-dark .interactive-flashcard-container {
  color: var(--text-color, #f8fafc);
  background: var(--card-bg, #0f172a);
  border-color: var(--border-color, #1e293b);
  box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
}

.flashcard-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.5rem;
}

@media (min-width: 1024px) {
  .flashcard-layout {
    grid-template-columns: 350px 1fr;
  }
}

.creator-column {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.viewer-column {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  min-width: 0;
}

.category-manager-box,
.flashcard-creator-box {
  background: var(--bg-soft, #f8fafc);
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: 0.75rem;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.theme-dark .category-manager-box,
.theme-dark .flashcard-creator-box {
  background: var(--bg-soft, #1e293b);
  border-color: var(--border-color, #334155);
}

.creator-title {
  font-size: 1.125rem;
  font-weight: 700;
  margin: 0;
  transition: transform 0.2s ease;
}

.category-creator-row {
  display: flex;
  gap: 0.5rem;
}

.category-input {
  flex: 1;
}

.compact-btn {
  padding: 0.375rem 0.75rem;
  font-size: 1.25rem;
  line-height: 1;
}

.category-list-container {
  border-top: 1px solid var(--border-color, #e2e8f0);
  padding-top: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.theme-dark .category-list-container {
  border-color: var(--border-color, #334155);
}

.categories-checkboxes-list {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
  max-height: 150px;
  overflow-y: auto;
}

.checkbox-label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  cursor: pointer;
  user-select: none;
  transition: transform 0.18s ease;
}

.checkbox-label span {
  transition: transform 0.18s ease;
}

.checkbox-label input[type="checkbox"] {
  width: 16px;
  height: 16px;
  cursor: pointer;
}

.select-control {
  appearance: none;
  background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2364748b' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 0.75rem center;
  background-size: 1rem;
  padding-right: 2.25rem;
}

.creator-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.form-field {
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
}

.form-field label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--muted-color, #64748b);
}

.theme-dark .form-field label {
  color: var(--muted-color, #94a3b8);
}

.form-textarea {
  width: 100%;
  padding: 0.625rem;
  border-radius: 0.375rem;
  border: 1px solid var(--border-color, #e2e8f0);
  background: var(--input-bg, #fff);
  color: inherit;
  font-size: 0.95rem;
  resize: vertical;
  box-sizing: border-box;
  transition: border-color 0.18s ease, box-shadow 0.18s ease, transform 0.18s ease;
}

.theme-dark .form-textarea {
  border-color: var(--border-color, #334155);
  background: var(--input-bg, #0f172a);
}

.form-textarea:focus {
  outline: none;
  border-color: var(--primary-color, #4f46e5);
  transform: translateY(-1px);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.12);
}

.primary-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: var(--primary-color, #4f46e5);
  color: var(--flashcard-white);
  border: none;
  border-radius: 0.375rem;
  padding: 0.625rem 1rem;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.2s ease, transform 0.16s ease, box-shadow 0.2s ease, filter 0.2s ease;
}

.primary-btn:hover {
  background: var(--primary-hover, #4338ca);
  transform: translateY(-1px);
  box-shadow: 0 10px 18px -10px rgba(79, 70, 229, 0.45);
}

.secondary-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  background: var(--bg-soft, #f1f5f9);
  color: var(--text-color, #1e293b);
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: 0.375rem;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}

.theme-dark .secondary-btn {
  background: var(--bg-soft, #1e293b);
  color: var(--text-color, #f8fafc);
  border-color: var(--border-color, #334155);
}

.secondary-btn:hover {
  background: var(--border-color, #e2e8f0);
  transform: translateY(-1px);
}

.theme-dark .secondary-btn:hover {
  background: var(--border-color, #334155);
}

.flashcard-viewer-box {
  background: var(--bg-soft, #f8fafc);
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: 0.75rem;
  padding: 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.theme-dark .flashcard-viewer-box {
  background: var(--bg-soft, #1e293b);
  border-color: var(--border-color, #334155);
}

.viewer-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.viewer-title {
  font-size: 1.125rem;
  font-weight: 700;
  margin: 0;
}

.progress-indicator {
  font-size: 0.875rem;
  font-weight: 600;
}

.deck-progress-bar-container {
  width: 100%;
  height: 6px;
  background: var(--border-color, #e2e8f0);
  border-radius: 3px;
  overflow: hidden;
}

.theme-dark .deck-progress-bar-container {
  background: var(--border-color, #334155);
}

.deck-progress-fill {
  width: 0%;
  height: 100%;
  background: var(--primary-color, #4f46e5);
  transition: width 0.35s cubic-bezier(0.22, 1, 0.36, 1);
  background-size: 200% 100%;
  animation: deck-progress-shimmer 2.8s linear infinite;
}

.theme-dark .deck-progress-fill {
  background: var(--primary-color, #818cf8);
}

.card-scene {
  width: 100%;
  height: 250px;
  perspective: 1000px;
  position: relative;
}

.flashcard-overlay {
  position: absolute;
  inset: 0;
  z-index: 5;
  pointer-events: none;
}

@media (min-width: 640px) {
  .card-scene {
    height: 300px;
  }
}

.flashcard-inner {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(0.22, 1, 0.36, 1);
  cursor: pointer;
  transform-origin: center center;

  --flashcard-progress: 0%;
}

.flashcard-inner:hover {
  transform: translateY(-3px) rotateX(1deg);
}

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

.flashcard-inner.flipped:hover {
  transform: rotateY(180deg) translateY(-3px) rotateX(1deg);
}

.flashcard-inner.slide-next {
  animation: flashcard-slide-next 0.34s cubic-bezier(0.22, 1, 0.36, 1);
}

.flashcard-inner.slide-prev {
  animation: flashcard-slide-prev 0.34s cubic-bezier(0.22, 1, 0.36, 1);
}

.flashcard-inner.card-pulse .card-side {
  animation: flashcard-pulse 0.32s ease;
}

.flashcard-inner::before,
.flashcard-inner::after {
  content: "";
  position: absolute;
  inset: -8%;
  border-radius: 1rem;
  pointer-events: none;
  opacity: 0;
}

.flashcard-inner::before {
  background: radial-gradient(circle, rgba(255, 255, 255, 0.35) 0%, rgba(255, 255, 255, 0) 60%);
}

.flashcard-inner::after {
  inset: -12%;
  background:
    radial-gradient(circle at 20% 20%, rgba(255, 255, 255, 0.6) 0 2px, transparent 3px),
    radial-gradient(circle at 80% 30%, rgba(255, 255, 255, 0.45) 0 2px, transparent 3px),
    radial-gradient(circle at 30% 80%, rgba(255, 255, 255, 0.55) 0 2px, transparent 3px),
    radial-gradient(circle at 75% 75%, rgba(255, 255, 255, 0.4) 0 2px, transparent 3px);
}

.flashcard-inner.burst-easy::before,
.flashcard-inner.burst-medium::before,
.flashcard-inner.burst-hard::before {
  animation: flashcard-burst-ring 0.55s ease-out;
}

.flashcard-inner.burst-easy::after,
.flashcard-inner.burst-medium::after,
.flashcard-inner.burst-hard::after {
  animation: flashcard-burst-sparkles 0.7s ease-out;
}

.flashcard-inner.burst-easy::before {
  box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.35);
}

.flashcard-inner.burst-medium::before {
  box-shadow: 0 0 0 0 rgba(245, 158, 11, 0.35);
}

.flashcard-inner.burst-hard::before {
  box-shadow: 0 0 0 0 rgba(239, 68, 68, 0.32);
}

.flashcard-inner.deck-streak .card-side {
  animation: flashcard-streak 0.6s ease;
}

.flashcard-inner.deck-cleared .card-side {
  animation: flashcard-cleared 0.9s cubic-bezier(0.22, 1, 0.36, 1);
}

.flashcard-inner[data-streak]:not([data-streak="0"])::after {
  content: attr(data-streak) "x";
  inset: auto 1rem 1rem auto;
  width: auto;
  height: auto;
  padding: 0.4rem 0.6rem;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.84);
  color: var(--flashcard-white);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  box-shadow: 0 12px 20px -12px rgba(0, 0, 0, 0.35);
}

.flashcard-inner.streak-pop[data-streak]:not([data-streak="0"])::after {
  animation: flashcard-streak-badge 0.45s ease;
}

.flashcard-hud {
  position: absolute;
  top: 0.85rem;
  right: 0.85rem;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: 0.45rem;
  pointer-events: none;
}

.flashcard-progress-chip,
.flashcard-streak-chip {
  backdrop-filter: blur(10px);
  box-shadow: 0 10px 18px -14px rgba(0, 0, 0, 0.22);
}

.flashcard-progress-chip {
  min-width: 74px;
  padding: 0.55rem 0.65rem;
  border-radius: 0.8rem;
  background: rgba(255, 255, 255, 0.8);
  border: 1px solid rgba(255, 255, 255, 0.55);
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 0.1rem;
}

.theme-dark .flashcard-progress-chip {
  background: rgba(15, 23, 42, 0.78);
  border-color: rgba(148, 163, 184, 0.2);
}

.flashcard-progress-percent {
  font-size: 1rem;
  font-weight: 800;
  line-height: 1;
}

.flashcard-progress-label {
  font-size: 0.68rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--muted-color, #64748b);
}

.flashcard-streak-chip {
  align-self: flex-end;
  padding: 0.35rem 0.6rem;
  border-radius: 999px;
  background: rgba(15, 23, 42, 0.84);
  color: var(--flashcard-white);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  opacity: 0.35;
  transform: scale(0.96);
  transition: opacity 0.18s ease, transform 0.18s ease;
}

.flashcard-streak-chip[data-active="true"] {
  opacity: 1;
  transform: scale(1);
}

@media (max-width: 639px) {
  .flashcard-progress-chip,
  .theme-dark .flashcard-progress-chip {
    background: rgba(255, 255, 255, 0.58);
    border-color: rgba(255, 255, 255, 0.28);
    backdrop-filter: blur(5px);
  }

  .theme-dark .flashcard-progress-chip {
    background: rgba(15, 23, 42, 0.46);
    border-color: rgba(148, 163, 184, 0.14);
  }

  .flashcard-streak-chip {
    background: rgba(15, 23, 42, 0.5);
    backdrop-filter: blur(5px);
  }

  .flashcard-streak-chip[data-active="false"] {
    opacity: 0.22;
  }
}

.card-side {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  backface-visibility: hidden;
  border-radius: 0.75rem;
  border: 1px solid var(--border-color, #e2e8f0);
  padding: 2rem;
  box-sizing: border-box;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.05);
  transition: box-shadow 0.24s ease, transform 0.24s ease;
  overflow: hidden;
}

.card-side::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(90deg, transparent 0%, rgba(255, 255, 255, 0.12) 50%, transparent 100%),
    linear-gradient(180deg, transparent calc(var(--flashcard-progress, 0%) - 2%), rgba(79, 70, 229, 0.08) var(--flashcard-progress, 0%), transparent calc(var(--flashcard-progress, 0%) + 10%));
  transform: translateX(-100%);
  animation: flashcard-sheen 4s ease-in-out infinite;
  pointer-events: none;
}

.flashcard-inner[data-score="easy"] .card-side {
  box-shadow: 0 10px 24px -18px rgba(16, 185, 129, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.05);
}

.flashcard-inner[data-score="medium"] .card-side {
  box-shadow: 0 10px 24px -18px rgba(245, 158, 11, 0.32), 0 2px 4px -1px rgba(0, 0, 0, 0.05);
}

.flashcard-inner[data-score="hard"] .card-side {
  box-shadow: 0 10px 24px -18px rgba(239, 68, 68, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.05);
}

.card-front {
  background: var(--card-bg, #fff);
}

.theme-dark .card-front {
  background: var(--card-bg, #0f172a);
  border-color: var(--border-color, #334155);
}

.card-back {
  background: linear-gradient(135deg, rgba(79, 70, 229, 0.03), rgba(129, 140, 248, 0.05));
  border-color: rgba(79, 70, 229, 0.2);
  transform: rotateY(180deg);
}

.theme-dark .card-back {
  background: linear-gradient(135deg, rgba(129, 140, 248, 0.08), rgba(79, 70, 229, 0.03));
  border-color: rgba(129, 140, 248, 0.3);
}

.card-side-label {
  position: absolute;
  top: 1rem;
  left: 1rem;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--muted-color, #64748b);
}

.theme-dark .card-side-label {
  color: var(--muted-color, #94a3b8);
}

.card-text-content {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.5;
  overflow-wrap: anywhere;
  max-height: 80%;
  overflow-y: auto;
}

@media (min-width: 640px) {
  .card-text-content {
    font-size: 1.5rem;
  }
}

.card-hint-text {
  position: absolute;
  bottom: 1rem;
  font-size: 0.75rem;
  color: var(--muted-color, #64748b);
  transition: transform 0.18s ease, opacity 0.18s ease;
}

.theme-dark .card-hint-text {
  color: var(--muted-color, #94a3b8);
}

.deck-navigation {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}

.nav-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--card-bg, #fff);
  color: var(--text-color, #1e293b);
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: 0.375rem;
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease, transform 0.16s ease;
}

.theme-dark .nav-btn {
  background: var(--card-bg, #0f172a);
  color: var(--text-color, #f8fafc);
  border-color: var(--border-color, #334155);
}

.nav-btn:hover {
  background: var(--bg-soft, #f8fafc);
  transform: translateY(-1px);
}

.theme-dark .nav-btn:hover {
  background: var(--bg-soft, #1e293b);
}

.flashcard-controls-box {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.evaluation-section {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.75rem;
}

.eval-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  border: 1px solid transparent;
  border-radius: 0.5rem;
  padding: 0.75rem;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s ease, transform 0.16s ease, box-shadow 0.2s ease;
  color: var(--flashcard-white);
}

.eval-btn:hover {
  transform: translateY(-2px) scale(1.01);
  box-shadow: 0 12px 20px -12px rgba(15, 23, 42, 0.35);
}

.score-easy {
  background: #10b981;
}

.score-easy:hover {
  background: #059669;
}

.score-medium {
  background: #f59e0b;
}

.score-medium:hover {
  background: #d97706;
}

.score-hard {
  background: #ef4444;
}

.score-hard:hover {
  background: #dc2626;
}

.utility-actions {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  border-top: 1px solid var(--border-color, #e2e8f0);
  padding-top: 1rem;
}

.theme-dark .utility-actions {
  border-color: var(--border-color, #1e293b);
}

@media (min-width: 640px) {
  .utility-actions {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.import-export-group {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.file-input-label {
  cursor: pointer;
}

.prompt-generator-box {
  background: var(--bg-soft, #f8fafc);
  border: 1px solid var(--border-color, #e2e8f0);
  border-radius: 0.75rem;
  padding: 1.25rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.theme-dark .prompt-generator-box {
  background: var(--bg-soft, #1e293b);
  border-color: var(--border-color, #334155);
}

.readonly-textarea {
  background: var(--bg-soft, #f1f5f9);
  color: var(--muted-color, #475569);
  font-size: 0.85rem;
  cursor: default;
}

.theme-dark .readonly-textarea {
  background: var(--bg-soft, #0f172a);
  color: var(--muted-color, #94a3b8);
}

.secondary-btn.copied {
  background: var(--flashcard-success);
  color: var(--flashcard-white);
  border-color: var(--flashcard-success);
  transform: scale(1.03);
}

.category-item-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  padding: 0.25rem 0;
  transition: transform 0.18s ease, opacity 0.18s ease;
}

.category-item-actions {
  display: flex;
  gap: 0.375rem;
}

.icon-btn {
  background: transparent;
  color: var(--muted-color, #64748b);
  border: none;
  cursor: pointer;
  padding: 0.25rem;
  border-radius: 0.25rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease, transform 0.16s ease;
}

.theme-dark .icon-btn {
  color: var(--muted-color, #94a3b8);
}

.icon-btn:hover {
  background: var(--border-color, #e2e8f0);
  color: var(--text-color, #1e293b);
  transform: translateY(-1px) scale(1.04);
}

.theme-dark .icon-btn:hover {
  background: var(--border-color, #334155);
  color: var(--text-color, #f8fafc);
}

.icon-btn.delete-btn-color:hover {
  background: rgba(239, 68, 68, 0.1);
  color: var(--flashcard-danger);
}

.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  backdrop-filter: blur(4px);
  animation: flashcard-modal-fade 0.18s ease;
}

.modal-content {
  background: var(--card-bg, #fff);
  border-radius: 0.75rem;
  padding: 1.5rem;
  max-width: 400px;
  width: 90%;
  box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  border: 1px solid var(--border-color, #e2e8f0);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  animation: flashcard-modal-pop 0.22s cubic-bezier(0.22, 1, 0.36, 1);
}

.theme-dark .modal-content {
  background: var(--card-bg, #0f172a);
  border-color: var(--border-color, #1e293b);
}

.modal-title {
  font-size: 1.125rem;
  font-weight: 700;
  margin: 0;
}

.modal-body {
  font-size: 0.95rem;
  margin: 0;
  color: var(--muted-color, #475569);
  line-height: 1.5;
}

.theme-dark .modal-body {
  color: var(--muted-color, #94a3b8);
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 0.75rem;
}

.category-manager-box:hover,
.flashcard-creator-box:hover,
.flashcard-viewer-box:hover,
.prompt-generator-box:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 24px -16px rgba(0, 0, 0, 0.1), 0 6px 10px -8px rgba(0, 0, 0, 0.08);
}

.creator-title:hover,
.checkbox-label:hover,
.category-item-row:hover {
  transform: translateX(2px);
}

.checkbox-label:hover span,
.card-side:hover .card-hint-text {
  transform: translateY(-1px);
}

.flashcard-inner:hover .card-side {
  box-shadow: 0 14px 20px -12px rgba(0, 0, 0, 0.12), 0 6px 10px -8px rgba(0, 0, 0, 0.08);
}

.primary-btn:active,
.secondary-btn:active,
.nav-btn:active,
.eval-btn:active,
.icon-btn:active {
  transform: translateY(1px) scale(0.985);
}

@media (prefers-reduced-motion: reduce) {
  .interactive-flashcard-container,
  .category-manager-box,
  .flashcard-creator-box,
  .flashcard-viewer-box,
  .prompt-generator-box,
  .form-textarea,
  .primary-btn,
  .secondary-btn,
  .flashcard-inner,
  .nav-btn,
  .eval-btn,
  .icon-btn,
  .modal-backdrop,
  .modal-content,
  .deck-progress-fill {
    animation: none;
    transition: none;
  }
}

@keyframes flashcard-tool-enter {
  from {
    opacity: 0;
    transform: translateY(6px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes deck-progress-shimmer {
  0% {
    background-position: 0% 50%;
  }

  100% {
    background-position: 200% 50%;
  }
}

@keyframes flashcard-slide-next {
  0% {
    opacity: 0.6;
    transform: translateX(18px) scale(0.985);
  }

  100% {
    opacity: 1;
    transform: translateX(0) scale(1);
  }
}

@keyframes flashcard-slide-prev {
  0% {
    opacity: 0.6;
    transform: translateX(-18px) scale(0.985);
  }

  100% {
    opacity: 1;
    transform: translateX(0) scale(1);
  }
}

@keyframes flashcard-pulse {
  0% {
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.05);
  }

  50% {
    box-shadow: 0 16px 24px -16px rgba(79, 70, 229, 0.28), 0 8px 12px -10px rgba(79, 70, 229, 0.18);
  }

  100% {
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.05);
  }
}

@keyframes flashcard-modal-fade {
  from {
    opacity: 0;
  }

  to {
    opacity: 1;
  }
}

@keyframes flashcard-modal-pop {
  from {
    opacity: 0;
    transform: translateY(10px) scale(0.98);
  }

  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes flashcard-burst-ring {
  0% {
    opacity: 0.85;
    transform: scale(0.92);
  }

  100% {
    opacity: 0;
    transform: scale(1.18);
  }
}

@keyframes flashcard-burst-sparkles {
  0% {
    opacity: 0;
    transform: scale(0.8);
  }

  35% {
    opacity: 1;
  }

  100% {
    opacity: 0;
    transform: scale(1.18);
  }
}

@keyframes flashcard-streak {
  0% {
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.05);
  }

  40% {
    box-shadow: 0 18px 28px -18px rgba(79, 70, 229, 0.26), 0 8px 18px -14px rgba(79, 70, 229, 0.2);
  }

  100% {
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.05);
  }
}

@keyframes flashcard-cleared {
  0% {
    transform: scale(1);
  }

  35% {
    transform: scale(1.03);
  }

  70% {
    transform: scale(0.995);
  }

  100% {
    transform: scale(1);
  }
}

@keyframes flashcard-streak-badge {
  0% {
    opacity: 0;
    transform: translateY(8px) scale(0.8);
  }

  70% {
    opacity: 1;
    transform: translateY(-2px) scale(1.06);
  }

  100% {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes flashcard-sheen {
  0% {
    transform: translateX(-100%);
    opacity: 0;
  }

  15% {
    opacity: 1;
  }

  40%,
  100% {
    transform: translateX(100%);
    opacity: 0;
  }
}

.primary-btn:disabled {
  background: var(--muted-color, #94a3b8);
  color: var(--border-color, #cbd5e1);
  cursor: not-allowed;
  opacity: 0.6;
  box-shadow: none;
}

.theme-dark .primary-btn:disabled {
  background: var(--border-color, #334155);
  color: var(--muted-color, #64748b);
}