/* ══════════════════════════════════════════════════════
   THEME: Birch — Scandinavian daylight
   ══════════════════════════════════════════════════════

   Birch-white and pine-night over green-tinted greys (tokens.css), pine
   and lichen as the only accent, Albert Sans throughout. The signature is
   what is missing: no uppercase and no letter-spacing anywhere in the
   interface, where every other preset uses tracked caps. Corners come from
   the theme radius (6px). */

/* ── Sentence case everywhere ─────────────────────── */
/* :is() takes its most specific argument, so one rule outranks every base
   and hero-specific caps rule it lists. */
[data-preset='birch']
  :is(
    .header__nav-link,
    .header__wordmark,
    .hero__title,
    .hero__subtitle,
    .hero__nav-link,
    .hero--stacked .hero__title,
    .hero--stacked .hero__subtitle,
    .hero--fullbleed .hero__subtitle,
    .hero--mosaic .hero__title,
    .hero--mosaic .hero__subtitle,
    .hero--mosaic .hero__nav-link,
    .hero__thumbnail-label,
    .hero__thumbnail-index,
    .hero__nav-index,
    .section-label,
    .album-header__title,
    .album-header__meta,
    .album-header__download,
    .subpage-title,
    .subpage-subtitle,
    .subpage-section__title,
    .subpage-section__desc,
    .subpage-toc__num,
    .subpage-toc__label,
    .subpage-grid__item-title,
    .subpage-grid__item-count,
    .subpage-grid__item-badge,
    .album-card__title,
    .album-card__count,
    .photo-grid__item-exif,
    .footer__name,
    .footer__legal-link,
    .back-link
  ) {
  text-transform: none;
  letter-spacing: 0;
  font-style: normal;
}

/* ── Header ───────────────────────────────────────── */
[data-preset='birch'] .header {
  background: color-mix(in srgb, var(--bg-primary) 92%, transparent);
  border-bottom-color: var(--border-subtle);
}

[data-preset='birch'] .header__nav-link {
  font-size: 0.85rem;
  font-weight: 500;
  border-bottom-color: transparent;
}

[data-preset='birch'] .header__nav-link:hover {
  border-bottom-color: transparent;
}

/* The active link sits in a soft pill rather than on an underline. */
[data-preset='birch'] .header__nav-link.active {
  border-bottom-color: transparent;
  background: var(--bg-card-hover);
  border-radius: 999px;
}

/* ── Type ─────────────────────────────────────────── */
[data-preset='birch'] .hero__title,
[data-preset='birch'] .album-header__title,
[data-preset='birch'] .subpage-title {
  font-weight: 500;
}

[data-preset='birch'] .section-label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-secondary);
}

/* ── Photo grid: soft corners, pill EXIF ──────────── */
[data-preset='birch'] .photo-grid {
  --grid-gap: 10px;
}

[data-preset='birch'] .photo-grid__item img {
  transition: filter 300ms ease;
}

[data-preset='birch'] .photo-grid__item:hover img {
  transform: none;
  filter: brightness(1.03);
}

[data-preset='birch'] .photo-grid__item-exif {
  left: 10px;
  right: auto;
  bottom: 10px;
  max-width: calc(100% - 20px);
  padding: 4px 10px;
  border-radius: 999px;
  background: color-mix(in srgb, var(--bg-card) 88%, transparent);
  color: var(--text-primary);
  font-size: 0.7rem;
  font-weight: 500;
  transition-duration: 300ms;
}

/* ── Covers: soft corners, a 2px lift ─────────────── */
[data-preset='birch'] .subpage-grid {
  --subpage-gap: 16px;
}

[data-preset='birch'] .subpage-grid__item,
[data-preset='birch'] .album-card {
  border-radius: var(--radius-sm);
  transition: transform 300ms ease;
}

[data-preset='birch'] .subpage-grid__item:hover,
[data-preset='birch'] .album-card:hover {
  transform: translateY(-2px);
}

[data-preset='birch'] .subpage-grid__item:hover img {
  transform: none;
  filter: brightness(0.8);
}

[data-preset='birch'] .subpage-grid__item-title,
[data-preset='birch'] .album-card__title {
  font-weight: 500;
}

/* ── Stacked hero: the photo inset with soft corners ─ */
[data-preset='birch'] .hero--stacked {
  gap: 12px;
  padding: 16px 24px 24px;
}

[data-preset='birch'] .hero__stacked-image {
  border-radius: var(--radius-md);
  overflow: hidden;
}

[data-preset='birch'] .hero--stacked .hero__title {
  font-family: var(--font-serif);
  font-weight: 500;
}

[data-preset='birch'] .hero--stacked .hero__subtitle {
  font-size: 0.95rem;
  color: rgba(255, 255, 255, 0.85);
}

[data-preset='birch'] .hero__thumbnail-strip {
  gap: 8px;
  background: none;
}

[data-preset='birch'] .hero__thumbnail-item {
  padding: 10px 18px;
  border-radius: 999px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
}

[data-preset='birch'] .hero__thumbnail-item:hover {
  background: var(--bg-card-hover);
}

[data-preset='birch'] .hero__thumbnail-label {
  font-size: 0.85rem;
  font-weight: 500;
}

@media (max-width: 640px) {
  [data-preset='birch'] .hero--stacked {
    padding: 8px 12px 16px;
  }

  [data-preset='birch'] .hero__stacked-overlay {
    padding: 32px 20px;
  }
}