#site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-height);
  display: flex;
  align-items: center;
  background-color: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition:
    box-shadow var(--duration-base) var(--ease-in-out),
    border-color var(--duration-base) var(--ease-in-out);
}

#site-header.is-scrolled {
  box-shadow: var(--shadow-sm);
  border-bottom-color: var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.header-logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.header-logo img {
  height: 42px;
  width: auto;
}

.header-nav {
  display: flex;
  align-items: center;
  gap: var(--space-6);
}

.header-nav .nav-link {
  font-size: var(--font-small);
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--color-text-secondary);
  transition: color var(--duration-fast) var(--ease-in-out);
  padding-bottom: 2px;
}

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

.header-cta {
  margin-left: var(--space-3);
}

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  gap: 6px;
  cursor: pointer;
}

.hamburger-line {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-navy);
  border-radius: 1px;
  transition:
    transform var(--duration-base) var(--ease-out-expo),
    opacity var(--duration-fast) var(--ease-in-out);
}

.hamburger.is-open .hamburger-line:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.hamburger.is-open .hamburger-line:nth-child(2) {
  opacity: 0;
}

.hamburger.is-open .hamburger-line:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* Mobile nav overlay */
.mobile-nav {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 99;
  background-color: rgba(11, 61, 140, 0.97);
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-6);
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--duration-base) var(--ease-in-out);
}

.mobile-nav.is-open {
  opacity: 1;
  pointer-events: auto;
}

.mobile-nav .nav-link {
  font-size: var(--font-h2);
  font-weight: 700;
  color: rgba(255, 255, 255, 0.85);
  letter-spacing: 0.02em;
  transition: color var(--duration-fast) var(--ease-in-out);
}

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

.mobile-nav .nav-link::after {
  background: var(--color-cyan);
}