.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  z-index: var(--z-header);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow var(--duration-base) var(--ease-out);
}

.site-header.scrolled {
  box-shadow: 0 1px 8px rgba(0, 0, 0, 0.04);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* Logo */
.logo {
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.5px;
  transition: opacity var(--duration-fast) var(--ease-out);
}

.logo:hover {
  opacity: 0.6;
}

.logo-dot {
  color: var(--color-accent);
}

/* Navigation */
.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
}

.nav-link {
  font-family: var(--font-heading);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.3px;
  color: var(--color-text-secondary);
  transition: color var(--duration-base) var(--ease-out);
  padding: var(--space-sm) 0;
}

.nav-link:hover {
  color: var(--color-text);
}

.nav-link:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 4px;
  border-radius: 2px;
}

.nav-link.active {
  color: var(--color-accent);
}

/* Products dropdown */
.nav-item--has-dropdown {
  position: relative;
}

.dropdown {
  position: absolute;
  top: calc(100% + 12px);
  right: -20px;
  width: 280px;
  padding: var(--space-sm);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: 0 8px 32px var(--color-shadow);
  z-index: var(--z-dropdown);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: opacity var(--duration-base) var(--ease-out-expo),
              transform var(--duration-base) var(--ease-out-expo),
              visibility var(--duration-base);
  pointer-events: none;
}

.nav-item--has-dropdown.dropdown-open .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
  pointer-events: auto;
}

/* Invisible bridge */
.dropdown::before {
  content: '';
  position: absolute;
  top: -16px;
  left: 0;
  right: 0;
  height: 16px;
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: 10px 12px;
  border-radius: var(--radius-md);
  transition: background var(--duration-fast) var(--ease-out);
}

.dropdown-item:hover {
  background: var(--color-bg);
}

.dropdown-item:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: -2px;
  border-radius: var(--radius-md);
}

.dropdown-item--active {
  background: var(--color-bg);
}

.dropdown-icon {
  flex-shrink: 0;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.5px;
}

.dropdown-icon--cyan {
  background: rgba(255, 87, 34, 0.08);
  color: var(--color-accent);
}

.dropdown-icon--purple {
  background: rgba(130, 100, 255, 0.08);
  color: var(--color-accent-purple);
}

.dropdown-content {
  display: flex;
  flex-direction: column;
  gap: 1px;
  flex: 1;
  min-width: 0;
}

.dropdown-name {
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text);
  line-height: 1.3;
}

.dropdown-desc {
  font-size: 11px;
  color: var(--color-text-muted);
  line-height: 1.3;
}

.dropdown-tag {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 1px;
  color: var(--color-text-muted);
  background: var(--color-bg);
  padding: 3px 7px;
  border-radius: var(--radius-sm);
}

/* Mobile toggle */
.mobile-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  padding: 4px;
  z-index: calc(var(--z-overlay) + 1);
}

.toggle-bar {
  display: block;
  width: 100%;
  height: 1.5px;
  background: var(--color-text-secondary);
  border-radius: 1px;
  transition: transform var(--duration-base) var(--ease-out-expo),
              opacity var(--duration-fast);
  transform-origin: center;
}

.mobile-toggle[aria-expanded="true"] .toggle-bar:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}

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

.mobile-toggle[aria-expanded="true"] .toggle-bar:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

/* Mobile nav */
@media (max-width: 768px) {
  .mobile-toggle {
    display: flex;
  }

  .main-nav {
    position: fixed;
    inset: 0;
    z-index: var(--z-overlay);
    background: var(--color-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--duration-slow) var(--ease-out-expo),
                visibility var(--duration-slow);
  }

  .main-nav.nav-open {
    opacity: 1;
    visibility: visible;
  }

  .nav-list {
    flex-direction: column;
    gap: var(--space-2xl);
  }

  .nav-link {
    font-size: 18px;
    letter-spacing: 0.5px;
  }

  .dropdown {
    position: static;
    width: 100%;
    max-width: 300px;
    opacity: 1;
    visibility: visible;
    transform: none;
    pointer-events: auto;
    box-shadow: none;
    border: 1px solid var(--color-border);
    margin-top: var(--space-md);
  }

  .dropdown::before {
    display: none;
  }

  .nav-item--has-dropdown.dropdown-open .dropdown {
    opacity: 1;
    visibility: visible;
    transform: none;
  }
}