/* Design Tokens — Academic / Editorial direction */
:root, [data-theme='light'] {
  /* Type scale */
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
  --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.5rem);

  /* Spacing */
  --space-1: 0.25rem; --space-2: 0.5rem; --space-3: 0.75rem;
  --space-4: 1rem; --space-5: 1.25rem; --space-6: 1.5rem;
  --space-8: 2rem; --space-10: 2.5rem; --space-12: 3rem;
  --space-16: 4rem; --space-20: 5rem; --space-24: 6rem;

  /* Radius */
  --radius-sm: 0.375rem; --radius-md: 0.5rem;
  --radius-lg: 0.75rem; --radius-xl: 1rem;
  --radius-full: 9999px;

  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Content widths */
  --content-narrow: 680px;
  --content-default: 1040px;
  --content-wide: 1280px;

  /* Fonts */
  --font-display: 'Source Serif 4', 'Iowan Old Style', Georgia, serif;
  --font-body: 'Inter', 'Helvetica Neue', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, monospace;

  /* ===== Academic palette — warm ivory + deep indigo ===== */
  --color-bg: #f8f5ee;
  --color-surface: #ffffff;
  --color-surface-2: #fbf9f3;
  --color-surface-offset: #f0ebdf;
  --color-surface-offset-2: #e9e3d4;
  --color-divider: #dcd4c0;
  --color-border: #c9bfa7;

  --color-text: #1a1f36;            /* Deep ink */
  --color-text-muted: #5b6378;      /* 4.7:1 on --color-bg */
  --color-text-faint: #8a8b94;
  --color-text-inverse: #fbf9f3;

  --color-primary: #1f3a93;         /* Scholarly indigo — 7.8:1 on ivory */
  --color-primary-hover: #15296b;
  --color-primary-active: #0f1f55;
  --color-primary-highlight: #d6def0;

  --color-accent: #a63a2a;          /* Oxblood — decorative only */
  --color-accent-hover: #86291b;

  --color-success: #1f6b3a;         /* 6.2:1 on ivory */
  --color-success-highlight: #d2e4d6;

  --color-warning: #8a5a00;
  --color-warning-highlight: #f0e4c7;

  --color-error: #a01b2a;
  --color-error-hover: #7a121e;
  --color-error-highlight: #f2d6d9;

  --color-info: #15526b;
  --color-info-highlight: #d1e0e8;

  /* Focus — always visible, 3:1 contrast min (WCAG 2.4.11) */
  --color-focus: #b84000;

  /* Shadows */
  --shadow-sm: 0 1px 2px oklch(0.2 0.02 280 / 0.08);
  --shadow-md: 0 4px 12px oklch(0.2 0.02 280 / 0.10);
  --shadow-lg: 0 12px 32px oklch(0.2 0.02 280 / 0.14);
}

[data-theme='dark'] {
  --color-bg: #121521;
  --color-surface: #191d2c;
  --color-surface-2: #1f2336;
  --color-surface-offset: #22273b;
  --color-surface-offset-2: #2b3046;
  --color-divider: #2e3349;
  --color-border: #3d4360;

  --color-text: #e8e9ee;
  --color-text-muted: #a6abbc;      /* 7.0:1 on --color-bg */
  --color-text-faint: #767c91;
  --color-text-inverse: #121521;

  --color-primary: #8a9fe0;         /* Desaturated indigo — 8.1:1 */
  --color-primary-hover: #a8b8eb;
  --color-primary-active: #c3cff2;
  --color-primary-highlight: #252e52;

  --color-accent: #e08775;
  --color-accent-hover: #eda593;

  --color-success: #6ec48a;
  --color-success-highlight: #1e3328;

  --color-warning: #e0b968;
  --color-warning-highlight: #3b2e17;

  --color-error: #e07585;
  --color-error-hover: #eda0ac;
  --color-error-highlight: #3b1c22;

  --color-info: #6cbad4;
  --color-info-highlight: #162e39;

  --color-focus: #ffa659;

  --shadow-sm: 0 1px 2px oklch(0 0 0 / 0.25);
  --shadow-md: 0 4px 12px oklch(0 0 0 / 0.35);
  --shadow-lg: 0 12px 32px oklch(0 0 0 / 0.45);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg: #121521;
    --color-surface: #191d2c;
    --color-surface-2: #1f2336;
    --color-surface-offset: #22273b;
    --color-surface-offset-2: #2b3046;
    --color-divider: #2e3349;
    --color-border: #3d4360;
    --color-text: #e8e9ee;
    --color-text-muted: #a6abbc;
    --color-text-faint: #767c91;
    --color-text-inverse: #121521;
    --color-primary: #8a9fe0;
    --color-primary-hover: #a8b8eb;
    --color-primary-active: #c3cff2;
    --color-primary-highlight: #252e52;
    --color-accent: #e08775;
    --color-accent-hover: #eda593;
    --color-success: #6ec48a;
    --color-success-highlight: #1e3328;
    --color-warning: #e0b968;
    --color-warning-highlight: #3b2e17;
    --color-error: #e07585;
    --color-error-hover: #eda0ac;
    --color-error-highlight: #3b1c22;
    --color-info: #6cbad4;
    --color-info-highlight: #162e39;
    --color-focus: #ffa659;
  }
}

/* ============ Layout ============ */
.page {
  min-height: 100dvh;
  display: grid;
  grid-template-rows: auto 1fr auto;
}

.container {
  width: 100%;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: clamp(var(--space-4), 4vw, var(--space-8));
}

.container--narrow { max-width: var(--content-default); }

/* ============ Header ============ */
.site-header {
  border-bottom: 1px solid var(--color-divider);
  background: var(--color-surface);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(180%) blur(6px);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding-block: var(--space-4);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text);
  text-decoration: none;
}

.brand__logo { color: var(--color-primary); width: 36px; height: 36px; flex-shrink: 0; }

.brand__name {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 600;
  letter-spacing: -0.01em;
  line-height: 1.1;
}

.brand__tagline {
  display: block;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-weight: 400;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px; height: 44px;         /* WCAG 2.5.8 target size */
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  border: 1px solid transparent;
}
.icon-btn:hover { background: var(--color-surface-offset); color: var(--color-text); }
.icon-btn:focus-visible { border-color: var(--color-focus); }

/* ============ Hero / intro ============ */
.hero {
  padding-block: clamp(var(--space-10), 6vw, var(--space-20));
  border-bottom: 1px solid var(--color-divider);
}

.hero__eyebrow {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

.hero__title {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.05;
  max-width: 24ch;
  margin-bottom: var(--space-5);
}

.hero__title em {
  font-style: italic;
  color: var(--color-primary);
}

.hero__lede {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 58ch;
  line-height: 1.5;
}

/* ============ Main tool layout ============ */
.tool {
  padding-block: clamp(var(--space-10), 5vw, var(--space-16));
}

.tool__grid {
  display: grid;
  gap: var(--space-8);
  grid-template-columns: minmax(0, 1fr);
}
@media (min-width: 960px) {
  .tool__grid { grid-template-columns: minmax(0, 1.1fr) minmax(0, 1fr); align-items: start; }
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: clamp(var(--space-5), 3vw, var(--space-8));
  box-shadow: var(--shadow-sm);
}

.card__header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-3);
  margin-bottom: var(--space-5);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-divider);
}

.card__title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 600;
  letter-spacing: -0.01em;
}

.card__counter {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-variant-numeric: tabular-nums;
}

/* ============ Form elements ============ */
.field { margin-bottom: var(--space-5); }
.field:last-child { margin-bottom: 0; }

.label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.label__hint {
  display: block;
  font-size: var(--text-xs);
  font-weight: 400;
  color: var(--color-text-muted);
  margin-top: 2px;
}

.textarea, .input, .select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-family: inherit;
  font-size: var(--text-base);
  color: var(--color-text);
  background: var(--color-surface-2);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  line-height: 1.5;
}
.textarea {
  min-height: 220px;
  resize: vertical;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.6;
}
.textarea:hover, .input:hover, .select:hover { border-color: var(--color-text-muted); }
.textarea:focus-visible, .input:focus-visible, .select:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
  border-color: var(--color-primary);
}

/* Fieldset reset (remove browser default border) */
fieldset {
  border: 0;
  padding: 0;
  margin: 0;
  min-width: 0;
}
legend {
  padding: 0;
}

/* Chips (bloom level / count selectors) */
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.chip {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  background: var(--color-surface-2);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-full);
  cursor: pointer;
  user-select: none;
}
.chip:hover { border-color: var(--color-text-muted); background: var(--color-surface-offset); }
.chip input { position: absolute; opacity: 0; pointer-events: none; }
.chip:has(input:checked) {
  background: var(--color-primary-highlight);
  border-color: var(--color-primary);
  color: var(--color-primary);
  font-weight: 600;
}
.chip:has(input:focus-visible) {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

.chip__level {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px; height: 20px;
  margin-right: var(--space-2);
  background: var(--color-surface-offset);
  color: var(--color-text-muted);
  font-size: 0.7rem;
  font-weight: 700;
  border-radius: var(--radius-full);
  font-variant-numeric: tabular-nums;
}
.chip:has(input:checked) .chip__level {
  background: var(--color-primary);
  color: var(--color-text-inverse);
}

/* Split grid for form controls */
.field-row {
  display: grid;
  gap: var(--space-4);
  grid-template-columns: minmax(0, 1fr);
}
@media (min-width: 600px) {
  .field-row--2 { grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); }
}

/* ============ Buttons ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 44px;
  padding: var(--space-3) var(--space-5);
  font-family: inherit;
  font-size: var(--text-sm);
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--color-text);
  background: var(--color-surface-2);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  text-decoration: none;
}
.btn:hover { background: var(--color-surface-offset); }
.btn:disabled { cursor: not-allowed; opacity: 0.55; }

.btn--primary {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--color-text-inverse);
}
.btn--primary:hover:not(:disabled) { background: var(--color-primary-hover); border-color: var(--color-primary-hover); }
.btn--primary:disabled { background: var(--color-surface-offset-2); border-color: var(--color-border); color: var(--color-text-muted); }

.btn--danger { color: var(--color-error); border-color: var(--color-error-highlight); background: transparent; }
.btn--danger:hover { background: var(--color-error-highlight); }

.btn--block { width: 100%; }

.btn__spinner {
  width: 16px; height: 16px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
}

/* ============ Status / alerts ============ */
.status {
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  display: flex;
  gap: var(--space-3);
  align-items: flex-start;
  margin-bottom: var(--space-4);
  border: 1px solid transparent;
}
.status__icon { flex-shrink: 0; width: 20px; height: 20px; margin-top: 2px; }
.status--info { background: var(--color-info-highlight); color: var(--color-info); border-color: color-mix(in oklab, var(--color-info) 25%, transparent); }
.status--success { background: var(--color-success-highlight); color: var(--color-success); border-color: color-mix(in oklab, var(--color-success) 25%, transparent); }
.status--warning { background: var(--color-warning-highlight); color: var(--color-warning); border-color: color-mix(in oklab, var(--color-warning) 25%, transparent); }
.status--error { background: var(--color-error-highlight); color: var(--color-error); border-color: color-mix(in oklab, var(--color-error) 25%, transparent); }

/* ============ Quiz output ============ */
.empty-state {
  text-align: center;
  padding-block: var(--space-12);
  color: var(--color-text-muted);
}

.empty-state__icon {
  width: 64px; height: 64px;
  margin: 0 auto var(--space-4);
  color: var(--color-text-faint);
  opacity: 0.7;
}

.empty-state__text {
  max-width: 36ch;
  margin-inline: auto;
  font-size: var(--text-sm);
}

.questions {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.question {
  padding: var(--space-5);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-md);
  background: var(--color-surface-2);
}

.question__header {
  display: flex;
  justify-content: space-between;
  gap: var(--space-3);
  align-items: flex-start;
  margin-bottom: var(--space-3);
}

.question__num {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-primary);
  font-variant-numeric: tabular-nums;
}

.question__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 2px var(--space-2);
  font-size: var(--text-xs);
  font-weight: 600;
  border-radius: var(--radius-full);
  line-height: 1.4;
  border: 1px solid transparent;
}
.badge--bloom { background: var(--color-primary-highlight); color: var(--color-primary); }
.badge--conf-high { background: var(--color-success-highlight); color: var(--color-success); }
.badge--conf-med { background: var(--color-warning-highlight); color: var(--color-warning); }
.badge--conf-low { background: var(--color-error-highlight); color: var(--color-error); }

.question__stem {
  font-size: var(--text-base);
  margin-bottom: var(--space-4);
  font-weight: 500;
  line-height: 1.55;
}

.options {
  list-style: none;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.option {
  display: flex;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-sm);
  font-size: var(--text-sm);
  line-height: 1.5;
}

.option--correct {
  background: var(--color-success-highlight);
  border-color: var(--color-success);
}

.option__letter {
  font-weight: 700;
  color: var(--color-text-muted);
  flex-shrink: 0;
  font-variant-numeric: tabular-nums;
  min-width: 1.5rem;
}
.option--correct .option__letter {
  color: var(--color-success);
}

.option__correct-mark {
  color: var(--color-success);
  flex-shrink: 0;
  margin-left: auto;
}

.question__rationale {
  margin-top: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface-offset);
  border-left: 3px solid var(--color-primary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-size: var(--text-sm);
}

.question__rationale-label {
  font-weight: 700;
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-primary);
  display: block;
  margin-bottom: var(--space-1);
}

/* ============ API-key modal ============ */
.dialog {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 0;
  background: var(--color-surface);
  color: var(--color-text);
  max-width: 520px;
  width: calc(100% - var(--space-8));
  box-shadow: var(--shadow-lg);
}
.dialog::backdrop { background: oklch(0 0 0 / 0.55); backdrop-filter: blur(2px); }
.dialog__inner { padding: clamp(var(--space-5), 3vw, var(--space-8)); }
.dialog__title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  font-weight: 600;
  margin-bottom: var(--space-2);
}
.dialog__lede {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-5);
}
.dialog__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  justify-content: flex-end;
  margin-top: var(--space-5);
}

/* ============ Footer ============ */
.site-footer {
  border-top: 1px solid var(--color-divider);
  background: var(--color-surface);
  padding-block: var(--space-8);
  margin-top: var(--space-16);
}
.site-footer__inner {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.site-footer a { color: var(--color-text-muted); text-decoration: underline; text-underline-offset: 3px; }
.site-footer a:hover { color: var(--color-text); }

/* ============ Progress ============ */
.progress {
  display: flex;
  gap: var(--space-2);
  align-items: center;
  padding: var(--space-3) var(--space-4);
  background: var(--color-info-highlight);
  color: var(--color-info);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  margin-bottom: var(--space-4);
}
.progress__spinner {
  width: 14px; height: 14px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  flex-shrink: 0;
}

/* ============ Bloom distribution meter ============ */
.meter {
  margin-top: var(--space-2);
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 2px;
  padding: var(--space-1);
  background: var(--color-surface-offset);
  border-radius: var(--radius-sm);
}
.meter__cell {
  height: 4px;
  background: var(--color-border);
  border-radius: 2px;
}
.meter__cell--active { background: var(--color-primary); }

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

.counter-row {
  display: flex;
  justify-content: space-between;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-top: var(--space-1);
  font-variant-numeric: tabular-nums;
}

/* ============ Action toolbar ============ */
.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  padding-bottom: var(--space-4);
  margin-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-divider);
}

/* High-contrast support */
@media (prefers-contrast: more) {
  :root, [data-theme='light'] {
    --color-border: #000000;
    --color-divider: #3a3a3a;
    --color-text-muted: #2a2a2a;
  }
  [data-theme='dark'] {
    --color-border: #ffffff;
    --color-divider: #b0b0b0;
    --color-text-muted: #e0e0e0;
  }
  .btn, .card, .question, .textarea, .input, .select, .chip { border-width: 2px; }
}