/* Header layout & branding */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  background: radial-gradient(circle at top left, rgba(0, 194, 168, 0.12), transparent 55%),
              radial-gradient(circle at top right, rgba(47, 123, 255, 0.12), transparent 55%),
              rgba(7, 10, 13, 0.96);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(148, 163, 184, 0.25);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--space-8);
  padding-bottom: var(--space-8);
  gap: var(--space-8);
}

/* Brand */
.site-header__brand {
  display: flex;
  align-items: center;
}

.site-header__logo-link {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  color: var(--color-text);
}

.site-header__logo-mark {
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 0.9rem;
  background: radial-gradient(circle at 30% 0%, var(--color-primary), transparent 65%),
              radial-gradient(circle at 70% 120%, var(--color-accent-blue), transparent 65%),
              #020617;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: 0.05em;
  font-size: 0.9rem;
  box-shadow: var(--shadow-sm);
}

.site-header__text-group {
  display: flex;
  flex-direction: column;
}

.site-header__title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: 1rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.site-header__subtitle {
  font-size: 0.7rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

/* Navigation */
.site-header__nav {
  display: flex;
  align-items: center;
  gap: var(--space-10);
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  list-style: none;
}

.site-header__nav-item a {
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--color-text-muted);
  position: relative;
  padding-bottom: 0.15rem;
}

.site-header__nav-item a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent-blue));
  transition: width var(--transition-base);
}

.site-header__nav-item a:hover,
.site-header__nav-item a[aria-current="page"] {
  color: var(--gray-50);
}

.site-header__nav-item a:hover::after,
.site-header__nav-item a[aria-current="page"]::after {
  width: 100%;
}

.site-header__cta-wrap {
  margin-left: 0.5rem;
}

.site-header__cta {
  font-size: 0.75rem;
}

/* Mobile toggle */
.site-header__toggle {
  display: none;
  position: relative;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: 999px;
  border: 1px solid rgba(148, 163, 184, 0.5);
  background: rgba(15, 23, 42, 0.9);
  cursor: pointer;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 0.25rem;
  padding: 0;
}

.site-header__toggle-bar {
  width: 1.25rem;
  height: 2px;
  border-radius: 999px;
  background: var(--gray-100);
  transition: transform var(--transition-base), opacity var(--transition-base), background var(--transition-base);
}

.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

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

.site-header__toggle[aria-expanded="true"] .site-header__toggle-bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* Mobile menu */
@media (max-width: 768px) {
  .site-header__toggle {
    display: inline-flex;
  }

  .site-header__nav {
    position: fixed;
    inset: 3.5rem 0 auto 0;
    background: rgba(7, 10, 13, 0.98);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid rgba(148, 163, 184, 0.25);
    flex-direction: column;
    align-items: flex-start;
    padding: 1rem var(--container-padding-x) 1.25rem;
    transform-origin: top;
    transform: scaleY(0.9);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity var(--transition-base), transform var(--transition-base), visibility var(--transition-base);
  }

  .site-header__nav--open {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: scaleY(1);
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
    width: 100%;
  }

  .site-header__cta-wrap {
    margin-left: 0;
    margin-top: 0.75rem;
    width: 100%;
  }

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

@media (max-width: 480px) {
  .site-header__subtitle {
    display: none;
  }
}