/* =====================================================================
   TOP NAV — sticky, palette-aware, mobile-friendly
   ===================================================================== */

.site-nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--color-bg) 90%, transparent);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-divider);
}

.site-nav-inner {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0.875rem 1.5rem;
  display: flex;
  align-items: center;
  gap: 2rem;
}

/* ---------- LOGO ---------- */

.site-nav-logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--color-fg);
  flex-shrink: 0;
}
.site-nav-logo:hover { color: var(--color-fg); }

.logo-mark {
  font-family: var(--font-display);
  font-size: 1.375rem;
  letter-spacing: 0.05em;
  background: var(--color-accent);
  color: var(--color-bg);
  padding: 0.25rem 0.5rem 0.125rem;
  line-height: 1;
  display: inline-block;
}

.logo-text {
  font-family: var(--font-heading);
  font-size: 1.0625rem;
  font-weight: 600;
  letter-spacing: -0.005em;
}

/* ---------- SECTION LINKS ---------- */

.site-nav-sections {
  display: flex;
  gap: 1.75rem;
  flex-grow: 1;
}

.nav-link {
  font-family: var(--font-display);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: 0.875rem;
  text-decoration: none;
  color: var(--color-fg-muted);
  padding: 0.25rem 0;
  border-bottom: 2px solid transparent;
  transition: color 0.15s ease, border-color 0.15s ease;
  white-space: nowrap;
}
.nav-link:hover { color: var(--color-fg); }
.nav-link.is-current {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
}

/* ---------- TOOLS (search + theme) ---------- */

.site-nav-tools {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  flex-shrink: 0;
}

.nav-search-btn,
.theme-switcher-btn {
  background: none;
  border: 1px solid transparent;
  cursor: pointer;
  font-size: 1.125rem;
  padding: 0.5rem 0.625rem;
  line-height: 1;
  border-radius: 4px;
  color: var(--color-fg);
  transition: background 0.15s ease, border-color 0.15s ease;
}
.nav-search-btn:hover:not(:disabled),
.theme-switcher-btn:hover {
  background: var(--color-bg-elevated);
  border-color: var(--color-divider);
}
.nav-search-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ---------- THEME SWITCHER DROPDOWN ---------- */

.theme-switcher {
  position: relative;
}

.theme-switcher-menu {
  position: absolute;
  top: calc(100% + 0.5rem);
  right: 0;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-divider);
  list-style: none;
  margin: 0;
  padding: 0.25rem;
  min-width: 12rem;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.10);
  border-radius: 6px;
  z-index: 100;
}

.theme-switcher-menu[hidden] { display: none; }

.theme-switcher-menu li { margin: 0; }

.theme-switcher-menu li button {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 0.5rem 0.75rem;
  font-family: var(--font-body);
  font-size: 0.9rem;
  color: var(--color-fg);
  cursor: pointer;
  border-radius: 3px;
  transition: background 0.12s ease;
}
.theme-switcher-menu li button:hover {
  background: color-mix(in srgb, var(--color-accent) 12%, transparent);
}
.theme-switcher-menu li button[aria-current="true"] {
  font-weight: 600;
  color: var(--color-accent);
}
.theme-switcher-menu li button[aria-current="true"]::before {
  content: "✓";
  margin-right: 0.5rem;
  font-weight: bold;
}

/* ---------- MOBILE ---------- */

@media (max-width: 768px) {
  .site-nav-inner {
    flex-wrap: wrap;
    gap: 0.5rem 1rem;
  }
  .logo-text { display: none; }
  .site-nav-sections {
    order: 3;
    width: 100%;
    overflow-x: auto;
    padding-bottom: 0.25rem;
    margin-top: 0.25rem;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
  }
  .site-nav-sections::-webkit-scrollbar { display: none; }
}