.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(18, 18, 26, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 2px solid var(--primary);
  box-shadow: 0 4px 20px rgba(0, 243, 255, 0.15);
  transition: all var(--transition-base);
}

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

.site-logo {
  font-family: var(--font-heading);
  font-size: var(--font-size-lg);
  color: var(--primary);
  text-shadow: var(--shadow-neon-primary);
  text-transform: uppercase;
  letter-spacing: 2px;
  text-decoration: none;
}

.site-logo:hover,
.site-logo:focus-visible {
  color: #fff;
  text-shadow: 0 0 15px var(--primary), 0 0 30px var(--primary);
}

.primary-nav__list {
  display: flex;
  list-style: none;
  gap: var(--space-6);
  margin: 0;
  padding: 0;
}

.primary-nav__link {
  font-family: var(--font-heading);
  font-family: 'Orbitron', monospace, sans-serif;
  font-size: var(--font-size-sm);
  font-weight: 700;
  text-transform: uppercase;
  color: var(--text-main);
  letter-spacing: 1px;
  position: relative;
  padding-bottom: var(--space-1);
}

.primary-nav__link::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 0%;
  height: 2px;
  background-color: var(--accent);
  box-shadow: var(--shadow-neon-accent);
  transition: width var(--transition-fast);
}

.primary-nav__link:hover::after,
.primary-nav__link:focus-visible::after {
  width: 100%;
}

.primary-nav__link:hover,
.primary-nav__link:focus-visible {
  color: var(--accent);
  text-shadow: 0 0 8px rgba(188, 19, 254, 0.6);
}

.mobile-menu-toggle {
  display: none;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
  z-index: 101;
}

.hamburger-box {
  width: 24px;
  height: 18px;
  display: inline-block;
  position: relative;
}

.hamburger-inner {
  display: block;
  top: 50%;
  margin-top: -1px;
}

.hamburger-inner,
.hamburger-inner::before,
.hamburger-inner::after {
  width: 24px;
  height: 2px;
  background-color: var(--primary);
  box-shadow: 0 0 5px var(--primary);
  position: absolute;
  transition: transform 0.15s ease, background-color 0.15s ease;
}

.hamburger-inner::before,
.hamburger-inner::after {
  content: '';
  display: block;
}

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

.hamburger-inner::after {
  bottom: -8px;
}

/* Mobile Menu Active State */
.mobile-menu-toggle[aria-expanded="true"] .hamburger-inner {
  background-color: transparent;
  box-shadow: none;
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-inner::before {
  transform: translate3d(0, 8px, 0) rotate(45deg);
  background-color: var(--accent);
  box-shadow: 0 0 5px var(--accent);
}

.mobile-menu-toggle[aria-expanded="true"] .hamburger-inner::after {
  transform: translate3d(0, -8px, 0) rotate(-45deg);
  background-color: var(--accent);
  box-shadow: 0 0 5px var(--accent);
}

/* Responsive Styling */
@media (max-width: 991px) {
  .mobile-menu-toggle {
    display: block;
  }
  
  .primary-nav {
    position: fixed;
    top: 80px;
    left: 0;
    width: 100%;
    height: calc(100vh - 80px);
    background-color: var(--bg-surface);
    border-top: 1px solid var(--gray-700);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    transform: translateX(100%);
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-base);
    overflow-y: auto;
  }

  .primary-nav.is-open {
    transform: translateX(0);
    opacity: 1;
    visibility: visible;
  }

  .primary-nav__list {
    flex-direction: column;
    align-items: center;
    gap: var(--space-8);
  }
  
  .primary-nav__link {
    font-size: var(--font-size-lg);
  }
}