/* layout — document chrome and the three-column shell.
   All sides are logical: the rail is inline-start, the aside inline-end,
   so ar/rtl and en/ltr mirror without a single left/right. */

body { display: flex; flex-direction: column; }

.site-header {
  position: sticky;
  inset-block-start: 0;
  z-index: 20;
  background: color-mix(in oklab, var(--bg) 88%, transparent);
  backdrop-filter: blur(12px);
  border-block-end: var(--border-width) solid var(--border);
}

.site-header__inner,
.site-shell,
.site-footer {
  max-inline-size: var(--page-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.site-header__inner {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  min-block-size: 64px;
}

.brand {
  display: inline-flex;
  flex-direction: column;
  gap: 2px;
  margin-inline-end: auto;
  text-decoration: none;
  color: var(--text);
}

.brand__name {
  font-size: var(--step-1);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.brand__tag {
  color: var(--text-muted);
  font-size: var(--step--1);
  line-height: 1.2;
}

.site-header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.site-header__link {
  display: inline-flex;
  align-items: center;
  min-block-size: 24px;
  color: var(--text-muted);
  font-size: var(--step--1);
  text-decoration: none;
}

.site-header__link:hover { color: var(--text); }

.site-header__form { display: contents; }

.lang-switch {
  color: var(--text-muted);
  font-size: var(--step--1);
  font-weight: 600;
  text-decoration: none;
  padding: var(--space-1) var(--space-2);
  border: var(--border-width) solid var(--border);
  border-radius: var(--radius-pill);
}

.lang-switch:hover {
  color: var(--text);
  border-color: var(--border-strong);
}

/* Three columns: rail | feed | aside. */
.site-shell {
  display: grid;
  grid-template-columns: var(--rail-inline) minmax(0, 1fr) var(--aside);
  column-gap: var(--col-gap);
  align-items: start;
  inline-size: 100%;
  flex: 1 0 auto;
}

.rail {
  position: sticky;
  inset-block-start: 80px;
  max-block-size: calc(100dvh - 96px);
  overflow-y: auto;
  overscroll-behavior: contain;
  padding-block: var(--space-6);
  font-size: var(--step--1);
}

.aside {
  position: sticky;
  inset-block-start: 80px;
  max-block-size: calc(100dvh - 96px);
  overflow-y: auto;
  overscroll-behavior: contain;
  padding-block: var(--space-6);
  display: grid;
  gap: var(--space-4);
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-4);
  justify-content: space-between;
  padding-block: var(--space-6);
  margin-block-start: var(--space-7);
  border-block-start: var(--border-width) solid var(--border);
  color: var(--text-muted);
  font-size: var(--step--1);
}

.site-footer__line {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.site-footer__nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4);
}

.site-footer__nav a {
  display: inline-flex;
  align-items: center;
  min-block-size: 24px;
  color: var(--text-muted);
  text-decoration: none;
}

.site-footer__nav a:hover { color: var(--text); }

/* Tablet: rails shrink before they fold. */
@media (max-width: 1119px) {
  .site-shell { grid-template-columns: 132px minmax(0, 1fr); }
  .aside {
    position: static;
    max-block-size: none;
    grid-column: 2;
    grid-row: 2;
    padding-block: 0 var(--space-6);
  }
}

/* Single column: the rail becomes a disclosure panel. */
@media (max-width: 899px) {
  .site-shell {
    grid-template-columns: minmax(0, 1fr);
    row-gap: var(--space-4);
  }

  .brand__tag { display: none; }

  .site-header__inner {
    flex-wrap: wrap;
    row-gap: var(--space-2);
    padding-block: var(--space-2);
  }

  .site-header__actions {
    order: 3;
    flex: 1 0 100%;
    justify-content: space-between;
  }

  .rail {
    position: static;
    max-block-size: none;
    grid-row: 1;
    padding-block: var(--space-4) 0;
    border-block-end: var(--border-width) solid var(--border);
  }

  .aside {
    grid-column: 1;
    grid-row: 3;
    padding-block: var(--space-4) var(--space-6);
    border-block-start: var(--border-width) solid var(--border);
  }

  .js .rail { display: none; }
  .js .rail.is-open { display: block; }

  .main { grid-row: 2; padding-block: var(--space-4) var(--space-6); }

  .site-footer { margin-block-start: var(--space-5); }
}

@media (min-width: 1440px) {
  .site-shell { column-gap: var(--space-7); }
}