/* ============================================
   HEADER STYLES
   ============================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(253, 252, 248, 0.95);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-gray-200);
  transition: box-shadow var(--transition-base);
}

.site-header.scrolled {
  box-shadow: var(--shadow-md);
}

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

/* Logo */
.site-logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.logo-text {
  font-family: var(--font-serif);
  font-size: var(--text-2xl);
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: -0.02em;
  transition: color var(--transition-fast);
}

.site-logo:hover .logo-text {
  color: var(--color-primary-hover);
}

/* Navigation */
.main-nav {
  display: flex;
  align-items: center;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.nav-menu a {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-text);
  padding: var(--space-2) 0;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-secondary);
  transition: width var(--transition-base);
}

.nav-menu a:hover {
  color: var(--color-secondary);
}

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

/* Header Actions */
.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-full);
  color: var(--color-text);
  background-color: transparent;
  transition: all var(--transition-fast);
}

.icon-btn:hover {
  background-color: var(--color-gray-100);
  color: var(--color-secondary);
}

.icon-btn i {
  font-size: var(--text-lg);
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 2.5rem;
  height: 2.5rem;
  gap: 5px;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
}

.hamburger-line {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-text);
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(2) {
  opacity: 0;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Responsive */
@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: flex;
  }
  
  .main-nav {
    order: 3;
  }
  
  .nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    background-color: var(--color-background);
    border-bottom: 1px solid var(--color-gray-200);
    padding: var(--space-4) var(--space-6);
    box-shadow: var(--shadow-lg);
    
    /* Hidden by default */
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: opacity var(--transition-base), visibility var(--transition-base), transform var(--transition-base);
  }
  
  .nav-menu.is-open {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
  }
  
  .nav-menu li {
    width: 100%;
    border-bottom: 1px solid var(--color-gray-100);
  }
  
  .nav-menu li:last-child {
    border-bottom: none;
  }
  
  .nav-menu a {
    display: block;
    padding: var(--space-4) 0;
    font-size: var(--text-lg);
    width: 100%;
  }
  
  .nav-menu a::after {
    display: none;
  }
}