:root {
  --flash-panel: color-mix(in srgb, var(--bg-surface) 90%, transparent);
  --flash-panel-strong: color-mix(in srgb, var(--bg-elevated) 94%, transparent);
  --flash-card: var(--bg-elevated);
  --flash-card-answer: color-mix(in srgb, var(--accent-primary) 14%, var(--bg-elevated));
  --flash-card-border: color-mix(in srgb, var(--accent-secondary) 30%, var(--border));
  --flash-soft-border: color-mix(in srgb, var(--accent-secondary) 24%, var(--border));
  --flash-accent-soft: color-mix(in srgb, var(--accent-primary) 13%, transparent);
  --flash-secondary-soft: color-mix(in srgb, var(--accent-secondary) 11%, transparent);
}

.flashcards-page {
  display: grid;
  gap: 18px;
}

.tiny-label {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-primary);
}

.panel-heading h2 {
  margin: 0;
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: 1.55rem;
  line-height: 1;
  letter-spacing: -0.04em;
}

.study-layout {
  display: grid;
  grid-template-columns: minmax(0, 1.45fr) minmax(320px, 0.55fr);
  gap: 18px;
  align-items: start;
}

.study-card,
.make-card {
  border: 1px solid var(--flash-soft-border);
  border-radius: 26px;
  background: var(--flash-panel);
  box-shadow: var(--shadow-lg);
}

.study-card {
  padding: clamp(16px, 2vw, 24px);
}

.make-card {
  display: grid;
  gap: 18px;
  padding: 18px;
}

.study-toolbar {
  display: grid;
  grid-template-columns: minmax(220px, 0.45fr) minmax(220px, 1fr);
  gap: 12px;
  margin-bottom: 14px;
}

.field {
  display: grid;
  gap: 7px;
}

.field span {
  color: var(--accent-secondary);
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.10em;
  text-transform: uppercase;
}

.input,
.textarea {
  border-radius: 16px;
  border-color: var(--flash-soft-border);
  background: var(--bg-input);
  color: var(--text-primary);
  font-size: 1rem;
}

.input:focus,
.textarea:focus {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 3px var(--flash-accent-soft);
}

.textarea {
  min-height: 96px;
  resize: vertical;
}

.deck-chips,
.subject-list {
  display: flex;
  flex-wrap: wrap;
  gap: 9px;
}

.deck-chip,
.subject-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border: 1px solid var(--flash-soft-border);
  border-radius: 999px;
  background: color-mix(in srgb, var(--bg-elevated) 72%, transparent);
  color: var(--text-secondary);
  cursor: pointer;
  transition: transform 160ms ease, border-color 160ms ease, background 160ms ease, color 160ms ease;
}

.deck-chip {
  padding: 10px 13px;
  font-weight: 700;
}

.subject-chip {
  padding: 8px 10px;
  font-size: 0.88rem;
}

.subject-open {
  border: 0;
  padding: 0;
  background: transparent;
  color: inherit;
  font: inherit;
  cursor: pointer;
}

.deck-chip:hover,
.subject-chip:hover {
  transform: translateY(-1px);
  border-color: var(--accent-primary);
  color: var(--text-primary);
}

.deck-chip.is-active,
.subject-chip.is-active {
  border-color: var(--accent-primary);
  background: var(--flash-accent-soft);
  color: var(--accent-primary);
}

.deck-chip small,
.subject-chip small {
  color: var(--text-muted);
  font-family: var(--font-mono);
  font-size: 0.72rem;
}

.flashcard {
  position: relative;
  display: grid;
  grid-template-rows: auto auto minmax(180px, 1fr) auto;
  gap: 14px;
  width: 100%;
  min-height: clamp(330px, 47vh, 520px);
  margin: 18px 0;
  padding: clamp(22px, 4vw, 46px);
  overflow: hidden;
  border: 1px solid var(--flash-card-border);
  border-radius: 32px;
  color: var(--text-primary);
  text-align: left;
  cursor: pointer;
  background:
    radial-gradient(circle at 12% 8%, var(--flash-secondary-soft), transparent 34%),
    linear-gradient(135deg, color-mix(in srgb, var(--bg-elevated) 96%, var(--accent-secondary) 4%), var(--flash-card));
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, var(--text-primary) 8%, transparent),
    inset 0 -28px 60px color-mix(in srgb, var(--bg-primary) 24%, transparent),
    var(--shadow-lg);
  isolation: isolate;
  transition: transform 180ms ease, box-shadow 180ms ease, background 180ms ease, border-color 180ms ease;
}

.flashcard::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: -1;
  opacity: 0.16;
  background-image:
    linear-gradient(color-mix(in srgb, var(--text-primary) 8%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--text-primary) 6%, transparent) 1px, transparent 1px);
  background-size: 34px 34px;
  mask-image: linear-gradient(to bottom, transparent, #000 18%, #000 82%, transparent);
}

.flashcard:hover {
  transform: translateY(-2px);
  border-color: var(--accent-primary);
  box-shadow:
    inset 0 1px 0 color-mix(in srgb, var(--text-primary) 10%, transparent),
    inset 0 -28px 60px color-mix(in srgb, var(--bg-primary) 28%, transparent),
    0 34px 84px color-mix(in srgb, var(--bg-primary) 70%, transparent);
}

.flashcard.is-answer {
  border-color: var(--accent-primary);
  background:
    radial-gradient(circle at 12% 8%, var(--flash-accent-soft), transparent 38%),
    linear-gradient(135deg, var(--flash-card-answer), var(--flash-card));
}

.card-side-label,
.card-deck-title,
.card-hint {
  font-family: var(--font-mono);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.card-side-label {
  justify-self: start;
  padding: 8px 12px;
  border: 1px solid color-mix(in srgb, var(--accent-primary) 28%, transparent);
  border-radius: 999px;
  background: var(--flash-accent-soft);
  color: var(--accent-primary);
  font-size: 0.75rem;
  font-weight: 800;
}

.card-deck-title {
  color: var(--text-secondary);
  font-size: 0.82rem;
}

.card-content {
  align-self: center;
  color: var(--text-primary);
  font-family: var(--font-ui);
  font-size: clamp(1.8rem, 4.4vw, 4.4rem);
  font-weight: 700;
  line-height: 1.02;
  letter-spacing: -0.05em;
  white-space: pre-wrap;
}

.flashcard.is-answer .card-content {
  font-size: clamp(1.45rem, 3vw, 3rem);
  line-height: 1.12;
}

.card-hint {
  color: var(--text-muted);
  font-size: 0.72rem;
}

.study-actions {
  display: grid;
  grid-template-columns: 1fr 1.35fr 1fr;
  gap: 10px;
}

.big-action {
  min-height: 54px;
  border: 1px solid transparent;
  border-radius: 18px;
  padding: 0 18px;
  font-family: var(--font-ui);
  font-size: 1rem;
  font-weight: 800;
  cursor: pointer;
  transition: transform 150ms ease, filter 150ms ease, border-color 150ms ease;
}

.big-action:hover:not(:disabled) {
  transform: translateY(-1px);
  filter: brightness(1.06);
}

.big-action:disabled {
  cursor: not-allowed;
  opacity: 0.45;
}

.primary-action {
  background: linear-gradient(135deg, var(--accent-primary), var(--accent-primary-hover));
  color: var(--text-on-primary);
}

.secondary-action {
  border-color: var(--flash-soft-border);
  background: var(--flash-secondary-soft);
  color: var(--text-primary);
}

.full-width {
  width: 100%;
}

.study-footer,
.subjects-header,
.quick-deck-form,
.panel-heading {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.helper-text {
  margin: 0;
  color: var(--text-secondary);
  font-size: 0.92rem;
}

.quiet-delete,
.text-action {
  border: 0;
  background: transparent;
  color: var(--text-secondary);
  cursor: pointer;
  text-decoration: underline;
  text-underline-offset: 4px;
}

.quiet-delete {
  color: var(--accent-error);
}

.simple-form {
  display: grid;
  gap: 13px;
}

.panel-heading {
  align-items: flex-start;
}

.subjects-box {
  display: grid;
  gap: 12px;
  padding-top: 14px;
  border-top: 1px solid var(--border);
}

.subjects-header h3 {
  margin: 0;
  color: var(--text-primary);
  font-size: 1rem;
}

.quick-deck-form {
  align-items: stretch;
}

.quick-deck-form .input {
  min-width: 0;
}

.delete-subject {
  display: inline-grid;
  place-items: center;
  width: 22px;
  height: 22px;
  border: 0;
  border-radius: 999px;
  background: color-mix(in srgb, var(--accent-error) 12%, transparent);
  color: var(--accent-error);
  cursor: pointer;
}

.toast {
  position: fixed;
  right: 18px;
  bottom: 18px;
  z-index: 50;
  max-width: min(360px, calc(100vw - 36px));
  padding: 13px 15px;
  border: 1px solid var(--accent-primary);
  border-radius: 16px;
  background: var(--bg-elevated);
  color: var(--text-primary);
  box-shadow: var(--shadow-lg);
}

@media (max-width: 1180px) {
  .study-layout {
    grid-template-columns: 1fr;
  }

  .make-card {
    grid-template-columns: minmax(0, 1fr) minmax(280px, 0.75fr);
  }

  .panel-heading,
  .simple-form,
  .subjects-box {
    grid-column: auto;
  }
}

@media (max-width: 760px) {
  .study-toolbar,
  .make-card {
    grid-template-columns: 1fr;
  }

  .study-actions {
    grid-template-columns: 1fr;
  }

  .flashcard {
    min-height: 300px;
    border-radius: 24px;
  }

  .card-content {
    font-size: clamp(1.7rem, 10vw, 3rem);
  }
}