.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  width: 100%;
  backdrop-filter: blur(18px) saturate(1.3);
  background: linear-gradient(135deg, rgba(248, 250, 252, 0.96), rgba(239, 246, 255, 0.9));
  border-bottom: 1px solid rgba(148, 163, 184, 0.25);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: 0.75rem;
  gap: 1rem;
}

.site-header__brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
}

.site-header__logo-mark {
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 999px;
  background: radial-gradient(circle at 30% 20%, #38bdf8, #1d4ed8);
  box-shadow: 0 14px 30px rgba(37, 99, 235, 0.55);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.site-header__logo-dot {
  width: 0.65rem;
  height: 0.65rem;
  border-radius: 999px;
  background: rgba(248, 250, 252, 0.95);
  box-shadow: 0 0 0 3px rgba(191, 219, 254, 0.9);
}

.site-header__brand-text {
  display: flex;
  flex-direction: column;
}

.site-header__brand-name {
  font-family: var(--font-display);
  font-weight: 650;
  font-size: 1rem;
  letter-spacing: -0.02em;
  color: var(--color-gray-900);
}

.site-header__brand-tagline {
  font-size: 0.75rem;
  color: var(--color-gray-500);
}

.site-header__nav {
  display: flex;
  align-items: center;
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.site-header__nav-item {
  list-style: none;
}

.site-header__nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: 0.4rem 0.95rem;
  border-radius: 999px;
  font-size: 0.85rem;
  color: var(--color-gray-700) !important;
  background: transparent;
  transition: background var(--transition-base), box-shadow var(--transition-base), transform var(--transition-fast), color var(--transition-base);
}

.site-header__nav-link:hover,
.site-header__nav-link:focus-visible {
  background: linear-gradient(135deg, rgba(219, 234, 254, 0.95), rgba(191, 219, 254, 0.92));
  color: var(--color-gray-900) !important;
  box-shadow: 0 10px 26px rgba(148, 163, 184, 0.35);
  transform: translateY(-1px);
}

.site-header__nav-item--cta {
  margin-left: 0.45rem;
}

.site-header__nav-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.35rem;
  padding: 0.55rem 1.2rem;
  border-radius: 999px;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  background: linear-gradient(135deg, var(--color-primary-gradient-start), var(--color-primary-gradient-end));
  color: var(--color-text-on-dark);
  box-shadow: 0 16px 40px rgba(37, 99, 235, 0.5);
  transition: transform var(--transition-base), box-shadow var(--transition-base), background var(--transition-base);
  border: 1px solid rgba(191, 219, 254, 0.5);
}

.site-header__nav-cta:hover,
.site-header__nav-cta:focus-visible {
  transform: translateY(-1px) scale(1.02);
  box-shadow: 0 20px 55px rgba(30, 64, 175, 0.65);
}

/* Mobile layout */
@media (max-width: 900px) {
  .site-header__inner {
    padding-block: 0.5rem;
  }

  .site-header__nav {
    position: fixed;
    inset-inline: 0;
    top: 70px;
    transform: translateY(-120%);
    transition: transform var(--transition-base);
    background: rgba(15, 23, 42, 0.92);
    backdrop-filter: blur(22px) saturate(1.4);
    border-bottom-left-radius: 1.5rem;
    border-bottom-right-radius: 1.5rem;
    box-shadow: 0 22px 60px rgba(15, 23, 42, 0.65);
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: stretch;
    padding: 4.25rem 1.25rem 1.5rem;
    gap: 0.4rem;
  }

  .site-header__nav-link {
    width: 100%;
    justify-content: flex-start;
    background: rgba(15, 23, 42, 0.15);
    color: var(--color-text-on-dark) !important;
    border-radius: 0.75rem;
    padding-block: 0.65rem;
  }

  .site-header__nav-link:hover,
  .site-header__nav-link:focus-visible {
    background: rgba(37, 99, 235, 0.65);
    color: #f9fafb;
  }

  .site-header__nav-item--cta {
    width: 100%;
    margin-left: 0;
    margin-top: 0.25rem;
  }

  .site-header__nav-cta {
    width: 100%;
    justify-content: center;
  }

  .site-header--menu-open .site-header__nav {
    transform: translateY(0);
  }

  .site-header--menu-open {
    box-shadow: 0 18px 45px rgba(15, 23, 42, 0.5);
  }
}

/* Nav toggle override: base.css already defines base styles */
.nav-toggle {
  margin-left: auto;
}

.site-header--menu-open .nav-toggle span:nth-child(1) {
  transform: translateY(3px) rotate(45deg);
  transform-origin: center;
}

.site-header--menu-open .nav-toggle span:nth-child(2) {
  transform: translateY(-3px) rotate(-45deg);
  transform-origin: center;
}

.site-header--menu-open .nav-toggle span:nth-child(3) {
  opacity: 0;
}

/* Utility: hidden when JS disabled fallback ensures nav always visible; JS will add class */
.site-header--js-enabled .site-header__nav {
  /* mobile-only transform is controlled via media query; keep noop for desktop */
}