/* Open navigation and individual appearance controls. */
.site-header { min-height: 120px; gap: 28px; padding-block: 28px; }
.site-header nav { gap: clamp(22px, 2.5vw, 38px); font: 500 19px/1.2 var(--display); }
.site-header nav a { position: relative; display: flex; align-items: center; min-height: 48px; padding: 10px 0; color: var(--ink); transition: color .2s; }
.site-header nav a::after { content: ""; position: absolute; bottom: 1px; left: 0; width: 100%; height: 3px; background: var(--dark); transform: scaleX(0); transform-origin: left; transition: transform .2s; }
.site-header nav a:hover, .site-header nav a:focus-visible { color: var(--dark); text-decoration: none; }
.site-header nav a:hover::after, .site-header nav a:focus-visible::after { transform: scaleX(1); }
body:has(#experience:target, #experience :target) .site-header a[href="#experience"]::after,
body:has(#education:target, #research:target) .site-header a[href="#education"]::after,
body:has(#work:target, #work :target) .site-header a[href="#work"]::after,
body:has(#playground:target, #playground :target, #about:target, #about :target) .site-header a[href="#playground"]::after { transform: scaleX(1); }
.header-actions { gap: 24px; }
.header-contact { font-size: 15px; }
.theme-switch { gap: 10px; padding: 0; border: 0; border-radius: 0; background: none; }
.theme-switch button { position: relative; width: 48px; height: 48px; border: 1px solid var(--line); border-radius: 50%; background: var(--surface); color: var(--muted); transition: transform .2s, color .2s, background .2s, border-color .2s, box-shadow .2s; }
.theme-switch svg { width: 22px; height: 22px; stroke-width: 1.8; }
.theme-switch button[aria-pressed=true] { color: var(--paper); background: var(--ink); border-color: var(--ink); box-shadow: 0 0 0 3px var(--paper), 0 0 0 4px var(--line-strong); }
.theme-switch button:hover:not([aria-pressed=true]) { color: var(--dark); border-color: var(--dark); background: var(--surface-raised); transform: translateY(-3px); }
.theme-switch button:active { transform: translateY(1px); }
.theme-switch button:focus-visible { outline-offset: 6px; }
@media (max-width: 1100px) {
  .site-header { flex-wrap: wrap; gap: 22px; }
  .site-header nav { order: 3; width: 100%; justify-content: space-between; gap: 22px; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); padding-block: 8px; font-size: 20px; }
  .site-header nav a { min-height: 52px; }
}
@media (max-width: 600px) {
  .site-header { padding-block: 24px; gap: 24px; }
  .site-header nav { gap: 10px; font-size: 17px; }
  .site-header nav a { min-height: 48px; }
  .header-actions { gap: 14px; }
}
@media (max-width: 370px) {
  .site-header nav { font-size: 15px; gap: 8px; }
  .theme-switch { gap: 8px; }
  .theme-switch button { width: 44px; height: 44px; }
}
@media (prefers-reduced-motion: reduce) {
  .site-header nav a, .site-header nav a::after, .theme-switch button { transition: none; }
}