/* layout.css — nav, footer, structure de page (design-system.md §5) */

.skip-link {
  position: absolute;
  top: -48px; left: var(--space-4);
  z-index: 1000;
  background: var(--color-surface);
  color: var(--color-text-strong);
  border: 1px solid var(--color-accent-border);
  border-radius: var(--radius-sm);
  padding: var(--space-2) var(--space-4);
  transition: top var(--motion-fast) var(--motion-easing);
}
.skip-link:focus {
  top: var(--space-4);
}

.container {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* Nav */
.site-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background-color var(--motion-base) var(--motion-easing),
              border-color var(--motion-base) var(--motion-easing);
}
.site-nav.is-scrolled {
  background: var(--color-bg);
  border-bottom-color: var(--color-border);
}
.site-nav__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}
.site-nav__brand { display: flex; align-items: center; gap: var(--space-2); font-weight: var(--weight-strong); color: var(--color-text-strong); }
.site-nav__brand img { height: 28px; }

.site-nav__links { display: flex; align-items: center; gap: var(--space-6); }
.site-nav__item { position: relative; }
.site-nav__link {
  display: flex; align-items: center; gap: var(--space-1);
  font-size: var(--text-small); font-weight: var(--weight-medium);
  color: var(--color-text-muted);
  padding: var(--space-2) 0;
}
.site-nav__link:hover, .site-nav__link[aria-expanded="true"] { color: var(--color-text-strong); }

.site-nav__dropdown {
  position: absolute;
  top: calc(100% + var(--space-3));
  left: 50%;
  transform: translateX(-50%);
  min-width: 320px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  opacity: 0;
  visibility: hidden;
  transform: translateX(-50%) translateY(-4px);
  transition: opacity var(--motion-fast) var(--motion-easing),
              transform var(--motion-fast) var(--motion-easing),
              visibility var(--motion-fast) var(--motion-easing);
}
.site-nav__item:hover .site-nav__dropdown,
.site-nav__item:focus-within .site-nav__dropdown {
  opacity: 1; visibility: visible; transform: translateX(-50%) translateY(0);
}
.site-nav__dropdown-item {
  display: block;
  padding: var(--space-3);
  border-radius: var(--radius-sm);
}
.site-nav__dropdown-item:hover { background: var(--color-bg-alt); }
.site-nav__dropdown-item strong { display: block; color: var(--color-text-strong); font-size: var(--text-small); margin-bottom: 2px; }
.site-nav__dropdown-item span { color: var(--color-text-muted); font-size: 13px; }

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

.site-nav__burger { display: none; }
.site-nav__actions--mobile { display: none; }

@media (max-width: 900px) {
  .site-nav__links { display: none; }
  .site-nav__burger { display: block; }
  .site-nav__actions--desktop { display: none; }
  .site-nav__actions--mobile {
    display: flex; flex-direction: column; gap: var(--space-3);
    width: 100%; margin-top: var(--space-4); padding-top: var(--space-4);
    border-top: 1px solid var(--color-border);
  }
  .site-nav.is-open .site-nav__links {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    position: absolute;
    top: 72px; left: 0; right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-4) var(--space-6) var(--space-6);
  }
  .site-nav.is-open .site-nav__item { width: 100%; }
  .site-nav.is-open .site-nav__dropdown {
    position: static; transform: none; opacity: 1; visibility: visible;
    min-width: 0; box-shadow: none; border: none; background: transparent;
    padding: 0 0 0 var(--space-4); display: none;
  }
  .site-nav.is-open .site-nav__item.is-expanded .site-nav__dropdown { display: block; }
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-16) 0 var(--space-8);
  margin-top: var(--space-32);
}
.site-footer__grid {
  display: grid;
  grid-template-columns: 1.4fr repeat(3, 1fr);
  gap: var(--space-8);
  margin-bottom: var(--space-12);
}
.site-footer__col h3 { font-size: var(--text-small); color: var(--color-text-strong); margin-bottom: var(--space-4); }
.site-footer__col ul { display: flex; flex-direction: column; gap: var(--space-2); }
.site-footer__col a { color: var(--color-text-muted); font-size: var(--text-small); }
.site-footer__col a:hover { color: var(--color-accent); }
.site-footer__bottom {
  display: flex; align-items: center; justify-content: space-between;
  padding-top: var(--space-6); border-top: 1px solid var(--color-border);
  color: var(--color-text-muted); font-size: var(--text-small);
}

@media (max-width: 900px) {
  .site-footer__grid { grid-template-columns: 1fr 1fr; }
  .site-footer__bottom { flex-direction: column; align-items: flex-start; gap: var(--space-3); }
}

/* Sections */
.section { padding: var(--space-24) 0; }
.section-alt { background: var(--color-bg-alt); }
.section-header { max-width: 640px; margin-bottom: var(--space-12); }

.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: var(--space-6); }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: var(--space-6); }
@media (max-width: 900px) {
  .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .site-footer__grid { grid-template-columns: 1fr; }
}