.site-header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--header-height);
  z-index: 500;
  background: var(--color-bg);
  border-bottom: 1px solid transparent;
  transition: border-color var(--dur-fast) var(--ease-soft),
    box-shadow var(--dur-fast) var(--ease-soft);
}

.site-header.is-scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: 0 8px 24px -18px rgba(41, 39, 37, 0.35);
}

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

.brand {
  display: flex;
  align-items: center;
  gap: 0.85rem;
}

.brand-logo {
  height: 128px;
  width: auto;
}

.brand-wordmark {
  height: 76px;
  width: auto;
}

.main-nav ul {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.nav-link {
  position: relative;
  font-size: 1.05rem;
  font-weight: 600;
  padding-block: 0.4rem;
}

.nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 100%;
  height: 2px;
  background: var(--color-text-secondary);
  transform: scaleX(0);
  transform-origin: right;
  transition: transform var(--dur-fast) var(--ease-soft);
}

.nav-link:hover::after,
.nav-link.active::after {
  transform: scaleX(1);
  transform-origin: left;
}

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

.nav-cta {
  background: var(--color-accent);
  color: var(--color-surface);
  padding: 0.7rem 1.5rem;
  border-radius: 999px;
}

.nav-cta::after {
  display: none;
}

.nav-cta:hover {
  background: var(--color-text-secondary);
  color: var(--color-surface);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 6px;
  width: 40px;
  height: 28px;
  justify-content: center;
}

.nav-toggle span {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--color-text-primary);
  transition: transform var(--dur-fast) var(--ease-soft), opacity var(--dur-fast) var(--ease-soft);
}

.nav-toggle.is-open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.is-open span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.is-open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}