/* Skip Link */
.skip-link {
  position: absolute;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-primary);
  color: var(--color-bg);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  font-weight: 600;
  z-index: 9999;
  transition: top var(--transition-base);
  text-decoration: none;
}

.skip-link:focus {
  top: var(--space-2);
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Header Layout */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(26, 26, 26, 0.95);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-neutral-800);
}

.header-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 80px;
}

/* Logo */
.logo {
  font-family: 'Space Grotesk', sans-serif;
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
  letter-spacing: -0.02em;
  transition: color var(--transition-base);
}

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

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

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list a {
  color: var(--color-text-secondary);
  font-weight: 500;
  font-size: var(--font-size-sm);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  transition: color var(--transition-base);
  position: relative;
  text-decoration: none;
  padding: var(--space-2) 0;
}

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

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

.nav-list a:hover::after,
.nav-list a:focus-visible::after,
.nav-list a[aria-current="page"]::after {
  width: 100%;
}

.nav-list .btn {
  margin-left: var(--space-4);
}

/* Mobile Toggle */
.mobile-menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  cursor: pointer;
  position: relative;
  z-index: 102;
  border-radius: var(--radius-md);
}

.hamburger {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-text);
  position: relative;
  transition: background-color var(--transition-base);
}

.hamburger::before,
.hamburger::after {
  content: '';
  position: absolute;
  left: 0;
  width: 24px;
  height: 2px;
  background-color: var(--color-text);
  transition: transform var(--transition-base);
}

.hamburger::before {
  top: -8px;
}

.hamburger::after {
  top: 8px;
}

/* Mobile Menu Open State */
.mobile-menu-toggle[aria-expanded="true"] .hamburger {
  background-color: transparent;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger::before {
  transform: translateY(8px) rotate(45deg);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger::after {
  transform: translateY(-8px) rotate(-45deg);
}

/* Mobile Responsive */
@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: flex;
  }
  
  .nav-list {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--color-bg);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: var(--space-6);
    transform: translateX(100%);
    transition: transform var(--transition-slow);
    z-index: 101;
    padding: var(--space-8);
  }
  
  .nav-list.active {
    transform: translateX(0);
    height: 100vh;
  }
  
  .nav-list a {
    font-size: var(--font-size-2xl);
    text-transform: none;
    letter-spacing: 0;
  }
  
  .nav-list .btn {
    margin-left: 0;
    margin-top: var(--space-4);
  }
}

/* Focus styles */
.mobile-menu-toggle:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

@media (prefers-reduced-motion: reduce) {
  .nav-list,
  .hamburger,
  .hamburger::before,
  .hamburger::after {
    transition: none;
  }
}