/* ═══════════════════════════════════════════════════════════════════════════
   site.css — Shared header + navigation styles
   Linked from every page. CSS custom properties (--var) are defined
   per-page in each <style> block's :root since token values are the same.
   ═══════════════════════════════════════════════════════════════════════════ */

/* ── Header shell ── */
header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 24px;
  position: sticky;
  top: 0;
  z-index: 100;
}
.header-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 16px;
  height: 58px;
}
.header-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  min-width: 0;
}
.header-label {
  font-family: var(--mono);
  font-size: 9px;
  color: var(--accent);
  letter-spacing: 2px;
  text-transform: uppercase;
  white-space: nowrap;
}

/* ── Site navigation ── */
.site-nav {
  display: flex;
  align-items: center;
  gap: 2px;
}
.site-nav-link {
  font-size: 12px;
  font-weight: 500;
  color: var(--muted);
  padding: 5px 10px;
  border-radius: var(--radius);
  border: 1px solid transparent;
  text-decoration: none;
  transition: color .15s, background .15s, border-color .15s;
  white-space: nowrap;
}
.site-nav-link:hover {
  color: var(--text);
  background: var(--surface2);
  border-color: var(--border);
  text-decoration: none;
}
.site-nav-link.active {
  color: var(--accent);
  background: rgba(0,212,255,.07);
  border-color: rgba(0,212,255,.25);
}

/* ── Header controls (right side) ── */
.header-controls {
  display: flex;
  align-items: center;
  gap: 10px;
}
.theme-btn {
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text);
  padding: 5px 12px;
  border-radius: var(--radius);
  cursor: pointer;
  font-size: 12px;
  transition: border-color .15s;
}
.theme-btn:hover {
  border-color: var(--accent);
}