.site-header { position: sticky; top: 0; z-index: 100; background: var(--surface); box-shadow: 0 2px 4px var(--hairline); }
.site-nav { max-width: var(--page-max-width); min-height: 60px; margin: auto; padding: 6px var(--page-gutter); display: flex; align-items: center; gap: 24px; }
.site-nav .logo { flex-shrink: 0; }
.site-nav-links { flex: 1; display: flex; flex-wrap: wrap; align-items: center; gap: 4px 24px; list-style: none; padding: 0; margin: 0; }
.site-nav-links a { display: inline-flex; align-items: center; min-height: 44px; color: var(--ink-70); text-decoration: none; font-size: 14px; border-bottom: 2px solid transparent; }
.site-nav-links a:hover { color: var(--ink); }
.site-nav-links a[aria-current] { color: var(--ink); border-bottom-color: var(--accent); font-weight: 700; }
.site-nav .cart-button { flex-shrink: 0; text-decoration: none; }
.theme-toggle { display: inline-flex; align-items: center; justify-content: center; flex: none; width: 40px; height: 40px; padding: 8px; border: 0; border-radius: 10px; background: transparent; color: var(--ink); cursor: pointer; transition: background-color .2s, color .2s; }
.theme-toggle svg { display: block; width: 22px; height: 22px; }
.theme-toggle:hover { background: var(--ink-10); }
.theme-toggle:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; }
.site-nav :focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; }
@media (max-width: 900px) {
  .site-nav { flex-wrap: wrap; gap: 0 16px; padding: 4px 16px; }
  .site-nav .cart-button { margin-left: auto; }
  .theme-toggle { margin-left: auto; }
  .site-nav-links { flex-basis: 100%; order: 1; gap: 0 16px; }
}