/* Header & Sticky Navbar */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.5rem;
}

/* Brand Logo */
.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
}

.brand-logo img {
  height: 2.75rem;
  width: auto;
  object-fit: contain;
}

/* Navigation Links */
.nav-menu {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.nav-link {
  font-weight: 500;
  color: var(--text-muted);
  font-size: 0.95rem;
  padding: 0.5rem 0.25rem;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary-400);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--brand-gradient);
  border-radius: var(--radius-full);
}

/* Right Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Theme Toggle Button & Dropdown */
.theme-toggle-wrapper {
  position: relative;
}

.theme-toggle-btn {
  background: var(--bg-muted);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  background-color: var(--bg-surface-elevated);
  border-color: var(--border-color-hover);
}

.theme-dropdown {
  position: absolute;
  right: 0;
  top: calc(100% + 0.5rem);
  background-color: var(--bg-surface-elevated);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  width: 9rem;
  padding: 0.375rem;
  display: none;
  flex-direction: column;
  gap: 0.25rem;
  z-index: 110;
}

.theme-dropdown.show {
  display: flex;
}

.theme-option-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  padding: 0.5rem 0.75rem;
  text-align: left;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  width: 100%;
  transition: all var(--transition-fast);
}

.theme-option-btn:hover,
.theme-option-btn.active {
  background-color: var(--bg-accent-subtle);
  color: var(--primary-400);
  font-weight: 600;
}

/* Mobile Hamburger Toggle */
.mobile-menu-toggle {
  display: none;
  background: transparent;
  border: none;
  color: var(--text-main);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.5rem;
}

/* Layout Main Content */
main {
  flex: 1;
}

/* Site Footer */
.site-footer {
  background-color: var(--bg-surface);
  border-top: 1px solid var(--border-color);
  padding: 3.5rem 0 2rem 0;
  margin-top: 4rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 2.5rem;
}

.footer-brand {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-width: 24rem;
}

.footer-brand img {
  height: 2.5rem;
  width: auto;
  object-fit: contain;
  align-self: flex-start;
}

.footer-tagline {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-muted);
}

.footer-col-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-main);
  margin-bottom: 1rem;
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
}

.footer-links a {
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: color var(--transition-fast);
}

.footer-links a:hover {
  color: var(--primary-400);
}

.footer-bottom {
  padding-top: 1.5rem;
  border-top: 1px solid var(--border-color);
  text-align: center;
  font-size: 0.875rem;
  color: var(--text-subtle);
}