/* ==========================================================================
   Layout — page shell, containers, section rhythm, surface themes
   ========================================================================== */

/* Container -------------------------------------------------------------- */

.container {
  width: 100%;
  max-width: calc(var(--layout-max) + var(--layout-gutter) * 2);
  margin-inline: auto;
  padding-inline: var(--layout-gutter);
}

.container--wide {
  max-width: calc(var(--layout-wide) + var(--layout-gutter) * 2);
}

.container--narrow {
  max-width: calc(730px + var(--layout-gutter) * 2);
}

/* Section ---------------------------------------------------------------- */

.section {
  position: relative;
  padding-block: var(--section-pad-y);
}

.section--tight {
  padding-block: var(--section-pad-y-tight);
}

.section--flush-top {
  padding-block-start: 0;
}

/* For a page with no hero. The header is fixed and sits over the top of the
   page, so a first section has to clear it itself — the ordinary section
   padding shrinks below the header's height on narrow screens. */
.section--below-header {
  padding-block-start: calc(
    var(--header-height) + var(--header-inset) * 2 + var(--space-3xl)
  );
}

.section--flush-bottom {
  padding-block-end: 0;
}

/* Surface themes --------------------------------------------------------- */
/* Each theme re-points the text roles so nested components inherit the
   correct foreground without knowing which band they sit in. */

.surface-dark {
  background-color: var(--surface-dark);
  color: var(--text-on-dark);
  --heading-color: var(--text-on-dark);
  --body-color: var(--text-on-dark-muted);
  --eyebrow-color: var(--text-eyebrow-light);
  --rule-color: var(--border-on-dark);
}

.surface-light {
  background-color: var(--surface-light);
  color: var(--text-body);
  --heading-color: var(--text-on-light);
  --body-color: var(--text-body);
  --eyebrow-color: var(--text-eyebrow-dark);
  --rule-color: var(--border-subtle);
}

.surface-muted {
  background-color: var(--surface-muted);
  color: var(--text-body);
  --heading-color: var(--text-on-light);
  --body-color: var(--text-body);
  --eyebrow-color: var(--text-eyebrow-dark);
  --rule-color: var(--border-subtle);
}

.surface-cool {
  background-color: var(--surface-cool);
  color: var(--text-body);
  --heading-color: var(--text-on-light);
  --body-color: var(--text-body);
  --eyebrow-color: var(--text-eyebrow-dark);
  --rule-color: var(--border-subtle);
}

.surface-wash {
  background-color: var(--surface-wash);
  color: var(--text-body);
  --heading-color: var(--text-on-light);
  --body-color: var(--text-body);
  --eyebrow-color: var(--text-eyebrow-dark);
  --rule-color: var(--border-subtle);
}

:is(.surface-dark, .surface-light, .surface-muted, .surface-cool, .surface-wash)
  :is(h1, h2, h3, h4, h5, h6) {
  color: var(--heading-color);
}

/* Stack — vertical rhythm without margin collapsing surprises ------------- */

.stack {
  display: flex;
  flex-direction: column;
  gap: var(--stack-gap, var(--space-md));
}

.stack--xs {
  --stack-gap: var(--space-xs);
}
.stack--sm {
  --stack-gap: var(--space-sm);
}
.stack--md {
  --stack-gap: var(--space-md);
}
.stack--lg {
  --stack-gap: var(--space-lg);
}
.stack--xl {
  --stack-gap: var(--space-xl);
}
.stack--2xl {
  --stack-gap: var(--space-2xl);
}

/* Cluster — inline group that wraps -------------------------------------- */

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

.cluster--center {
  justify-content: center;
}

/* Grid ------------------------------------------------------------------- */

.grid {
  display: grid;
  gap: var(--grid-gap, var(--space-lg));
}

.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));
}

@media (max-width: 900px) {
  .grid--3,
  .grid--4 {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 600px) {
  .grid--2,
  .grid--3,
  .grid--4 {
    grid-template-columns: minmax(0, 1fr);
  }
}

/* Section intro — eyebrow + heading + lede, centred by default ----------- */

.section-intro {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
  text-align: center;
  max-width: 730px;
  margin-inline: auto;
}

.section-intro--start {
  align-items: flex-start;
  text-align: start;
  margin-inline: 0;
}

.section-intro > p {
  color: var(--body-color, var(--text-body));
}

/* Measure helpers -------------------------------------------------------- */

.measure {
  max-width: 58ch;
}

.measure--tight {
  max-width: 46ch;
}