.site-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-3);
  width: 100%;
  padding: var(--space-3) var(--space-5);
  border-bottom: 1px solid var(--border);
  background: color-mix(in srgb, var(--bg) 70%, transparent);
  backdrop-filter: blur(10px);
  position: sticky;
  top: 0;
  z-index: 2;
}

.site-nav .brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 1.2rem;
  text-decoration: none;
  color: var(--heading);
}

.site-nav .brand img {
  height: 28px;
  width: auto;
  display: block;
}

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

.site-nav nav a {
  position: relative;
  text-decoration: none;
  color: var(--text);
  font-weight: 600;
  transition: color var(--dur-med) var(--ease);
}

.site-nav nav a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -4px;
  width: 0;
  height: 1px;
  background: var(--accent);
  transform: translateX(-50%);
  transition: width var(--dur-med) var(--ease);
}

.site-nav nav a:hover {
  color: var(--accent-2);
  text-shadow: 0 0 10px color-mix(in srgb, var(--accent) 50%, transparent);
}

.site-nav nav a:hover::after {
  width: 100%;
}

.theme-switch {
  display: inline-flex;
  border: 1px solid var(--border-strong);
  border-radius: 8px;
  overflow: hidden;
}

.theme-btn {
  width: 34px;
  height: 34px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border: none;
  background: var(--bg-elevated);
  color: var(--text-muted);
  cursor: pointer;
  transition: color var(--dur-med) var(--ease), background var(--dur-med) var(--ease), box-shadow var(--dur-med) var(--ease);
}

.theme-btn:not(:last-child) {
  border-right: 1px solid var(--border-strong);
}

.theme-btn svg {
  width: 16px;
  height: 16px;
}

.theme-btn:hover {
  color: var(--accent);
  box-shadow: 0 0 14px color-mix(in srgb, var(--accent) 35%, transparent);
}

.theme-btn[aria-pressed="true"] {
  background: var(--accent);
  color: var(--bg);
}

@media (max-width: 480px) {
  .site-nav {
    flex-direction: column;
    text-align: center;
    padding: var(--space-3);
  }
  .site-nav nav {
    justify-content: center;
    gap: var(--space-3);
  }
}