/* ==========================================================================
   North — Layout
   Containers, sections, grids, header and footer. Shared by every page.
   ========================================================================== */

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

.section { padding-block: var(--section-pad); }
.section--alt  { background: var(--paper-2); }
.section--ink  { background: var(--ink); color: var(--white); }
.section--red  { background: var(--red); color: var(--white); }

/* Two-column section: label/heading left, content right */
.split {
  display: grid;
  gap: var(--space-6);
}
@media (min-width: 900px) {
  .split { grid-template-columns: 4fr 8fr; gap: var(--space-8); }
}

/* ---------- Skip link ---------- */
.skip-link {
  position: absolute;
  left: var(--space-4);
  top: -100px;
  z-index: 100;
  padding: var(--space-2) var(--space-4);
  background: var(--ink);
  color: var(--white);
  font-size: var(--fs-sm);
}
.skip-link:focus { top: var(--space-4); }

/* ---------- Header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  height: var(--header-h);
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  backdrop-filter: saturate(1.2) blur(10px);
  -webkit-backdrop-filter: saturate(1.2) blur(10px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur) var(--ease);
}
.site-header.is-scrolled { border-bottom-color: var(--line); }

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  height: 100%;
}

.site-header__logo img { height: 22px; width: auto; }

.site-header__nav {
  display: flex;
  align-items: center;
  gap: var(--space-5);
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--ink);
  color: var(--muted-dark);
  font-size: var(--fs-sm);
  padding-block: var(--space-7);
}

.site-footer__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
}

.site-footer__logo img { height: 18px; width: auto; }

.site-footer__meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2) var(--space-5);
  font-weight: 500;
}
.site-footer__meta a { color: var(--white); text-decoration: none; }
.site-footer__meta a:hover { color: var(--white); text-decoration: underline; }