/* =============================================================
   LAYOUT — containers, section rhythm, generic grids, utilities.
   Structure only; no colour decisions beyond token references.
   ============================================================= */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-pad);
}

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

.section {
  padding-block: var(--section-space);
  background-color: var(--color-bg);
  color: var(--color-text);
}

.section--subtle { background-color: var(--color-bg-subtle); }

.section--tight { padding-block: calc(var(--section-space) * 0.6); }

/* --- Section heading block ---------------------------------- */
.section-head {
  max-width: var(--container-narrow);
  margin-bottom: var(--space-xl);
}

.section-head--center {
  margin-inline: auto;
  text-align: center;
}

.section-head > * + * { margin-top: var(--space-sm); }

.section-head p {
  font-size: var(--text-md);
  color: var(--color-text-muted);
}

/* --- Grids --------------------------------------------------- */
.grid {
  display: grid;
  gap: var(--grid-gap);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }

/* Auto-fitting grid for card decks of unknown length */
.grid--auto {
  grid-template-columns: repeat(auto-fit, minmax(min(17rem, 100%), 1fr));
}

@media (max-width: 60rem) {
  .grid--3,
  .grid--4 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 40rem) {
  .grid--2,
  .grid--3,
  .grid--4 { grid-template-columns: minmax(0, 1fr); }
}

/* --- Split (asymmetric two-column) --------------------------- */
.split {
  display: grid;
  gap: var(--grid-gap);
  align-items: center;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
}

@media (max-width: 62rem) {
  .split { grid-template-columns: minmax(0, 1fr); }
}

/* --- Stack & cluster ---------------------------------------- */
.stack > * + * { margin-top: var(--space-sm); }
.stack-lg > * + * { margin-top: var(--space-md); }

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

/* --- Utilities ----------------------------------------------- */
.text-center { text-align: center; }
.text-muted  { color: var(--color-text-muted); }
.lead {
  font-size: var(--text-md);
  color: var(--color-text-muted);
}

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

.skip-link {
  position: absolute;
  top: var(--space-2xs);
  left: var(--space-2xs);
  z-index: var(--z-overlay);
  padding: var(--space-2xs) var(--space-sm);
  background-color: var(--color-accent);
  color: var(--color-accent-contrast);
  border-radius: var(--radius-sm);
  transform: translateY(-200%);
  transition: transform var(--dur-fast) var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* --- Scroll reveal (progressive enhancement) ------------------ */
.reveal {
  opacity: 0;
  transform: translateY(var(--space-sm));
  transition:
    opacity var(--dur-slow) var(--ease),
    transform var(--dur-slow) var(--ease);
}
.reveal.is-visible {
  opacity: 1;
  transform: none;
}
/* `.reveal` is only ever added by JS, so the page renders fully
   visible when scripting is unavailable. */