/* Header Layout */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
}

.logo {
  font-family: 'DM Serif Display', serif;
  font-size: var(--text-2xl);
  color: var(--color-navy);
  font-weight: 400;
  letter-spacing: -0.02em;
  text-decoration: none;
  line-height: 1;
}

.logo:hover {
  text-decoration: none;
  color: var(--color-navy-light);
}

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

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

.nav-list a {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-slate-600);
  text-decoration: none;
  padding: var(--space-2) 0;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-list a:hover,
.nav-list a[aria-current="page"] {
  color: var(--color-navy);
}

.nav-list a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--color-navy);
  transform: scaleX(0);
  transition: transform var(--transition-base);
}

.nav-list a:hover::after,
.nav-list a[aria-current="page"]::after {
  transform: scaleX(1);
}

/* Mobile Toggle */
.nav-toggle {
  display: none;
  background: transparent;
  border: none;
  padding: var(--space-2);
  cursor: pointer;
  z-index: 50;
}

.hamburger,
.hamburger::before,
.hamburger::after {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-slate-900);
  transition: transform var(--transition-base), opacity var(--transition-base);
}

.hamburger {
  position: relative;
}

.hamburger::before,
.hamburger::after {
  content: '';
  position: absolute;
  left: 0;
}

.hamburger::before {
  top: -7px;
}

.hamburger::after {
  bottom: -7px;
}

/* Mobile Styles */
@media (max-width: 768px) {
  .nav-toggle {
    display: block;
  }
  
  .nav-list {
    position: fixed;
    top: 4rem;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--color-bg);
    flex-direction: column;
    align-items: flex-start;
    padding: var(--space-6);
    gap: var(--space-4);
    transform: translateX(100%);
    transition: transform var(--transition-slow);
    box-shadow: var(--shadow-xl);
    z-index: 30;
  }
  
  .nav-list.is-open {
    transform: translateX(0);
  }
  
  .nav-list a {
    font-size: var(--text-lg);
    padding: var(--space-3) 0;
    width: 100%;
    border-bottom: 1px solid var(--color-slate-100);
  }
  
  .nav-list a::after {
    display: none;
  }
  
  .nav-toggle[aria-expanded="true"] .hamburger {
    background-color: transparent;
  }
  
  .nav-toggle[aria-expanded="true"] .hamburger::before {
    transform: translateY(7px) rotate(45deg);
  }
  
  .nav-toggle[aria-expanded="true"] .hamburger::after {
    transform: translateY(-7px) rotate(-45deg);
  }
}