@layer elements {

  /* ── SITE NAV ────────────────────────────────────────────────────────── */
  .site-nav {
    grid-column: 1;
    grid-row: 1 / -1;
    position: sticky;
    top: 0;
    height: 100vh;
    padding: 48px 32px 48px 24px;
    display: flex;
    flex-direction: column;
    border-right: 1px solid var(--color-rule);
  }

  .site-nav__mark {
    font-family: var(--font-mono);
    font-size: var(--size-xs);
    font-weight: 400;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--color-ink-muted);
    margin-bottom: 40px;
    text-decoration: none;
    display: block;
  }

  .site-nav__mark span {
    display: block;
    color: var(--color-ink);
    font-size: var(--size-sm);
    font-weight: 500;
    letter-spacing: 0.06em;
    margin-bottom: 4px;
  }

  .site-nav__rooms {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 2px;
  }

  .site-nav__room a {
    font-family: var(--font-mono);
    font-size: var(--size-xs);
    letter-spacing: 0.10em;
    text-transform: uppercase;
    text-decoration: none;
    color: var(--color-ink-muted);
    display: flex;
    align-items: baseline;
    gap: 8px;
    padding: 6px 0;
    transition: color 0.15s ease;
  }

  .site-nav__room a:hover { color: var(--color-ink); }
  .site-nav__room--active a { color: var(--color-accent); }

  .site-nav__room .numeral {
    font-size: var(--size-xs);
    opacity: 0.5;
    min-width: 16px;
  }

  .site-nav__room--active .numeral { opacity: 1; }

  .site-nav__foot {
    margin-top: auto;
    font-family: var(--font-mono);
    font-size: var(--size-xs);
    color: var(--color-ink-muted);
    line-height: 1.8;
  }

  .site-nav__foot a {
    color: var(--color-ink-muted);
    text-decoration: none;
  }

  .site-nav__foot a:hover { color: var(--color-accent); }

  /* ── NAV COLLAPSE — 768px ───────────────────────────────────────────── */
  @media (max-width: 768px) {
    .page {
      grid-template-columns: 1fr;
    }

    .site-nav {
      position: relative;
      height: auto;
      flex-direction: row;
      flex-wrap: wrap;
      padding: 20px 24px;
      border-right: none;
      border-bottom: 1px solid var(--color-rule);
    }

    .site-nav__mark    { margin-bottom: 0; margin-right: 24px; }
    .site-nav__rooms   { flex-direction: row; flex-wrap: wrap; gap: 0 16px; }
    .site-nav__foot    { display: none; }
    .main              { padding: 0 24px; }
  }

}