/* =========================================================================
   layout.css
   Layer: Structural (header, footer, containers, grid scaffolding)

   ARCHITECTURAL NOTE:
   BEM naming (.block__element--modifier) is used throughout so class
   names are self-documenting and collision-free without needing CSS
   Modules or a build step — important since this project intentionally
   has no bundler yet (see CLAUDE.md).
   ========================================================================= */

/* -------------------------------------------------------------------------
   Container
   A single .container class (rather than per-section max-widths) keeps
   the content column consistent across all six pages.
   ------------------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--max-width-content);
  margin-inline: auto;
  padding-inline: var(--space-3);
}

main {
  display: block;
}

section {
  padding-block: var(--space-5);
}

/* -------------------------------------------------------------------------
   Site Header / Navigation
   Flexbox (not floats) is used here specifically because it handles
   vertical centering and space-distribution natively, which floats
   cannot do without clearfix hacks — a meaningful cross-browser and
   maintainability win for a nav bar.
   ------------------------------------------------------------------------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-2);
}

.site-header__logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 0.02em;
}

.site-nav__toggle {
  display: none; /* shown only at mobile breakpoint below */
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-1);
}

.site-nav__toggle-bar {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-primary);
  margin-block: 5px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.site-nav__list {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.site-nav__link {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text);
  transition: color var(--transition-base);
}

.site-nav__link:hover,
.site-nav__link:focus-visible,
.site-nav__link--active {
  color: var(--color-secondary);
}

/* Mobile nav: collapse to a toggleable drawer under 768px. Mobile-first
   media queries (min-width) are avoided here in favor of a single
   max-width breakpoint because the nav is "desktop-simple,
   mobile-complex" — the opposite of most content, so overriding down is
   clearer than building up. */
@media (max-width: 768px) {
  .site-nav__toggle {
    display: block;
  }

  .site-nav__list {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background-color: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-base);
  }

  .site-nav__list--open {
    max-height: 400px; /* large enough to fit all items; transition-friendly vs. height:auto */
  }

  .site-nav__link {
    display: block;
    padding: var(--space-2) var(--space-3);
    border-top: 1px solid var(--color-border);
  }
}

/* -------------------------------------------------------------------------
   Site Footer
   CSS Grid (not Flexbox) is used here because the footer has a genuine
   2-dimensional layout (columns AND rows of unequal content length) —
   the case where Grid is the correct semantic tool over Flexbox.
   ------------------------------------------------------------------------- */
.site-footer {
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
  padding-block: var(--space-5) var(--space-3);
}

.site-footer__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.site-footer__heading {
  color: var(--color-text-inverse);
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-2);
}

.site-footer__link {
  display: block;
  color: rgba(255, 255, 255, 0.75);
  font-size: var(--font-size-sm);
  padding-block: var(--space-1);
  transition: color var(--transition-base);
}

.site-footer__link:hover,
.site-footer__link:focus-visible {
  color: var(--color-text-inverse);
}

.site-footer__bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  padding-top: var(--space-3);
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.6);
  text-align: center;
}

.site-footer__legal-entity {
  margin-top: var(--space-1);
}

.site-footer__address {
  margin-top: var(--space-1);
}

.site-footer__legal-links {
  display: flex;
  justify-content: center;
  gap: var(--space-3);
  margin-top: var(--space-1);
}

.site-footer__legal-links .site-footer__link {
  display: inline;
  padding: 0;
}