/* Header layout */
.site-header {
  position: sticky;
  top: 0;
  z-index: 40;
  width: 100%;
  background-color: rgba(244, 247, 245, 0.96);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border-subtle);
}

.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: var(--space-3);
  padding-bottom: var(--space-3);
}

/* Branding */
.site-header__branding {
  display: flex;
  align-items: center;
}

.site-header__brand-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  color: var(--color-text);
}

.site-header__logo-mark {
  width: 40px;
  height: 40px;
  border-radius: 12px;
  background: radial-gradient(circle at 20% 20%, #e6f4eb, #2f6f4e);
  box-shadow: var(--shadow-sm);
  position: relative;
  overflow: hidden;
}

.site-header__logo-mark::after {
  content: "";
  position: absolute;
  inset: 35% 12% auto 12%;
  border-radius: 999px;
  background: rgba(244, 247, 245, 0.65);
}

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

.site-header__title {
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  font-size: var(--font-size-xs);
}

.site-header__tagline {
  font-size: var(--font-size-xs);
  color: var(--color-muted-text);
}

/* Navigation */
.site-header__nav {
  display: flex;
}

.site-header__nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  list-style: none;
}

.site-header__nav-link {
  position: relative;
  display: inline-flex;
  align-items: center;
  padding: 0.25rem 0;
  font-size: var(--font-size-sm);
  color: var(--color-muted-text);
}

.site-header__nav-link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 0;
  height: 2px;
  border-radius: 999px;
  background-color: var(--color-primary);
  transition: width var(--transition-normal) ease;
}

.site-header__nav-link:hover,
.site-header__nav-link:focus-visible {
  color: var(--color-text);
}

.site-header__nav-link:hover::after,
.site-header__nav-link:focus-visible::after {
  width: 100%;
}

.site-header__nav-item--primary-cta {
  margin-left: var(--space-2);
}

.site-header__cta-link {
  font-size: var(--font-size-sm);
  padding-inline: 1.25rem;
}

/* Mobile menu toggle */
.site-header__menu-toggle {
  display: none;
  align-items: center;
  gap: var(--space-2);
  padding: 0.35rem 0.75rem;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  color: var(--color-text);
  background-color: transparent;
}

.site-header__menu-toggle-box {
  display: inline-flex;
  flex-direction: column;
  gap: 4px;
}

.site-header__menu-toggle-bar {
  width: 18px;
  height: 2px;
  border-radius: 999px;
  background-color: var(--color-text);
  transition: transform var(--transition-normal) ease, opacity var(--transition-normal) ease;
}

.site-header__menu-toggle-text {
  font-size: var(--font-size-xs);
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.site-header__menu-toggle:focus-visible {
  outline: 2px solid var(--color-primary-strong);
  outline-offset: 3px;
}

/* Mobile state (JS-enhanced) */
.site-header--menu-open .site-header__menu-toggle-bar:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}

.site-header--menu-open .site-header__menu-toggle-bar:nth-child(2) {
  opacity: 0;
}

.site-header--menu-open .site-header__menu-toggle-bar:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* Responsive behaviour */
@media (max-width: 768px) {
  .site-header__inner {
    padding-top: var(--space-2);
    padding-bottom: var(--space-2);
  }

  .site-header__menu-toggle {
    display: inline-flex;
  }

  .site-header__nav {
    position: absolute;
    inset-inline: 0;
    top: 100%;
    background-color: #ffffff;
    border-bottom: 1px solid var(--color-border-subtle);
    box-shadow: var(--shadow-sm);
    max-height: 0;
    overflow: hidden;
    visibility: hidden;
    opacity: 0;
    transition: max-height var(--transition-slow) ease, opacity var(--transition-normal) ease, visibility var(--transition-normal) ease;
  }

  .site-header__nav-list {
    flex-direction: column;
    align-items: flex-start;
    padding: var(--space-3) var(--space-4) var(--space-4);
    gap: var(--space-2);
  }

  .site-header__nav-item--primary-cta {
    width: 100%;
    margin-left: 0;
    margin-top: var(--space-2);
  }

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

  /* JS-controlled open state */
  .site-header--menu-open .site-header__nav {
    max-height: 320px;
    visibility: visible;
    opacity: 1;
  }
}

@media (min-width: 769px) {
  .site-header__nav {
    position: static;
    max-height: none;
    visibility: visible !important;
    opacity: 1 !important;
    box-shadow: none;
    border-bottom: none;
  }
}

/* High-contrast focus support for nav links on light background */
.site-header__nav-link:focus-visible {
  outline: 2px solid var(--color-primary-strong);
  outline-offset: 3px;
}

/* Reduce motion preference */
@media (prefers-reduced-motion: reduce) {
  .site-header,
  .site-header__nav,
  .site-header__menu-toggle-bar {
    transition: none !important;
  }
}