/* ---------- Tokens ---------- */

:root {
  --color-ink: #26215c;
  --color-ink-soft: #4a4577;
  --color-accent: #534ab7;
  --color-accent-strong: #3c3489;
  --color-surface: #f8f6f1;
  --color-card: #ffffff;
  --color-border: #c9b99a;
  --color-control-border: #8a7a5c; /* 3:1 against surface and card, for input and chip edges */
  --color-mark: #f3e3b8;
  --color-focus: #534ab7;

  --font-body: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --radius: 0.75rem;
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 1rem;
  --space-4: 1.5rem;
  --space-5: 2.5rem;
  --max-width: 72rem;

  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-ink: #f1eee6;
    --color-ink-soft: #c8c3d9;
    --color-accent: #a9a2f0;
    --color-accent-strong: #c6c1ff;
    --color-surface: #16132e;
    --color-card: #221e45;
    --color-border: #4a4470;
    --color-control-border: #7f79ad;
    --color-mark: #6b5a2a;
    --color-focus: #c6c1ff;
  }
}

/* ---------- Base ---------- */

*,
*::before,
*::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 1.0625rem;
  line-height: 1.6;
  color: var(--color-ink);
  background: var(--color-surface);
}

h1,
h2,
h3 {
  line-height: 1.2;
  margin: 0;
}

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 3px;
}

.wrap {
  width: min(100% - 2 * var(--space-3), var(--max-width));
  margin-inline: auto;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  margin: -1px;
  padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  left: var(--space-3);
  top: -3rem;
  padding: var(--space-2) var(--space-3);
  background: var(--color-card);
  color: var(--color-ink);
  border-radius: var(--radius);
  z-index: 1;
}

.skip-link:focus {
  top: var(--space-3);
}

/* ---------- Header ---------- */

.site-header {
  padding-block: var(--space-5) var(--space-4);
}

.eyebrow {
  margin: 0 0 var(--space-2);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.site-header h1 {
  font-size: clamp(2rem, 5vw, 3rem);
}

.lede {
  max-width: 40rem;
  margin: var(--space-3) 0 0;
  color: var(--color-ink-soft);
}

/* ---------- Controls ---------- */

.article-filter h2 {
  font-size: 1.375rem;
  margin-bottom: var(--space-3);
}

.filter-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: var(--space-3) var(--space-4);
  padding: var(--space-4);
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.field {
  display: grid;
  gap: var(--space-1);
  flex: 1 1 16rem;
}

.field label,
.chips legend {
  font-weight: 600;
  font-size: 0.9375rem;
}

input[type="search"] {
  font: inherit;
  padding: var(--space-2) var(--space-3);
  color: var(--color-ink);
  background: var(--color-surface);
  border: 1px solid var(--color-control-border);
  border-radius: calc(var(--radius) / 1.5);
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin: 0;
  padding: 0;
  border: 0;
  flex: 2 1 24rem;
}

.chips legend {
  /* Legends ignore flex layout; float it so it sits on its own line. */
  float: left;
  width: 100%;
  margin-bottom: var(--space-1);
}

.chip {
  display: inline-flex;
  align-items: center;
  min-height: 2.75rem; /* comfortable touch target */
  padding-inline: var(--space-3);
  border: 1px solid var(--color-control-border);
  border-radius: 999px;
  cursor: pointer;
  user-select: none;
  transition: background-color 150ms ease, color 150ms ease;
}

.chip:hover {
  border-color: var(--color-accent);
}

/* The radio is visually hidden, so the label shows its checked and focus states. */
.chip:has(input:checked) {
  background: var(--color-accent-strong);
  border-color: var(--color-accent-strong);
  color: #fff;
}

.chip:has(input:focus-visible) {
  outline: 3px solid var(--color-focus);
  outline-offset: 3px;
}

@media (prefers-color-scheme: dark) {
  .chip:has(input:checked) {
    color: var(--color-surface);
  }
}

button {
  font: inherit;
  min-height: 2.75rem;
  padding-inline: var(--space-4);
  border-radius: 999px;
  cursor: pointer;
  color: var(--color-accent-strong);
  background: transparent;
  border: 1px solid var(--color-accent);
}

button:hover {
  background: color-mix(in srgb, var(--color-accent) 12%, transparent);
}

/* ---------- Results ---------- */

.status {
  margin: var(--space-4) 0 var(--space-3);
  color: var(--color-ink-soft);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(100%, 18rem), 1fr));
  gap: var(--space-3);
  margin: 0 0 var(--space-5);
  padding: 0;
  list-style: none;
}

.card-grid[aria-busy="true"] {
  opacity: 0.6;
}

.card article {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  height: 100%;
  padding: var(--space-4);
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.card__meta {
  margin: 0;
  font-size: 0.875rem;
  color: var(--color-ink-soft);
}

.card__category {
  font-weight: 600;
  color: var(--color-accent);
}

.card__title {
  font-size: 1.1875rem;
}

.card__summary {
  margin: 0;
}

mark {
  background: var(--color-mark);
  color: inherit;
  border-radius: 0.2em;
  padding-inline: 0.1em;
}

.empty-state {
  grid-column: 1 / -1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4);
  border: 1px dashed var(--color-border);
  border-radius: var(--radius);
}

.empty-state p {
  margin: 0;
}

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
  }
}