/* Layout primitives: containers, header, footer, page scaffolding. */

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

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

/* Sticky footer scaffold. */
.site {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}
.site__main { flex: 1 0 auto; }

/* Vertical rhythm between major page sections. */
.section { padding-block: var(--space-xl); }
.section + .section { padding-top: 0; }
.section__head { margin-bottom: var(--space-md); }

/* ---- Skip link (accessibility) ---- */
.skip-link {
  position: absolute;
  left: var(--space-sm);
  top: -3rem;
  background: var(--color-ink);
  color: var(--color-bg);
  padding: var(--space-2xs) var(--space-sm);
  border-radius: var(--radius-sm);
  z-index: 100;
  transition: top var(--transition);
}
.skip-link:focus { top: var(--space-sm); }

/* ---- Header ---- */
.site-header {
  border-bottom: var(--border-hairline);
  background: color-mix(in srgb, var(--color-bg) 92%, transparent);
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: saturate(1.1);
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  min-height: 4rem;
}
.brand {
  font-weight: var(--weight-bold);
  font-size: var(--text-lg);
  letter-spacing: var(--tracking-tight);
  text-decoration: none;
  color: var(--color-ink);
}
.brand:hover { color: var(--color-ink); }

.site-header__right { display: flex; align-items: center; gap: var(--space-sm); }

.nav { display: flex; align-items: center; gap: var(--space-xs); }
.nav a {
  text-decoration: none;
  color: var(--color-ink-soft);
  padding: var(--space-3xs) var(--space-2xs);
  border-radius: var(--radius-sm);
  font-weight: var(--weight-medium);
}
.nav a:hover { color: var(--color-ink); }
.nav a[aria-current="page"] {
  color: var(--color-accent);
  box-shadow: inset 0 -2px 0 var(--color-accent);
}

/* Mobile nav: a no-JS <details> disclosure. */
.nav-toggle { display: none; }

@media (max-width: 40rem) {
  .nav-toggle {
    display: block;
    position: relative;
  }
  .nav-toggle > summary {
    list-style: none;
    cursor: pointer;
    padding: var(--space-2xs) var(--space-xs);
    border: var(--border-hairline);
    border-radius: var(--radius-sm);
    font-weight: var(--weight-medium);
  }
  .nav-toggle > summary::-webkit-details-marker { display: none; }
  .nav-toggle[open] > summary { border-color: var(--color-border-strong); }
  .nav-toggle .nav {
    position: absolute;
    right: 0;
    top: calc(100% + var(--space-2xs));
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: var(--color-bg);
    border: var(--border-hairline);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-md);
    padding: var(--space-2xs);
    min-width: 11rem;
  }
  .nav--inline { display: none; }
}

@media (min-width: 40.01rem) {
  .nav-toggle { display: none; }
}

/* ---- Footer ---- */
.site-footer {
  border-top: var(--border-hairline);
  margin-top: var(--space-2xl);
  padding-block: var(--space-lg);
  color: var(--color-ink-muted);
  font-size: var(--text-sm);
}
.site-footer__inner {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  justify-content: space-between;
  align-items: center;
}
.site-footer a { color: var(--color-ink-soft); }

/* ---- Generic responsive grid for cards ---- */
.grid {
  display: grid;
  gap: var(--space-md);
}
.grid--2 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 20rem), 1fr)); }
.grid--3 { grid-template-columns: repeat(auto-fit, minmax(min(100%, 17rem), 1fr)); }

/* Two-column page layout (e.g. About: prose + aside). */
.split {
  display: grid;
  gap: var(--space-xl);
  grid-template-columns: minmax(0, 2fr) minmax(0, 1fr);
}
@media (max-width: 52rem) {
  .split { grid-template-columns: 1fr; gap: var(--space-lg); }
}