.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(18px);
  background: rgba(255, 249, 236, 0.78);
  border-bottom: 1px solid transparent;
  transition: border-color 180ms ease, box-shadow 180ms ease;
}

.site-header.is-scrolled {
  border-bottom-color: var(--border);
  box-shadow: 0 12px 30px rgba(31, 47, 31, 0.08);
}

.nav {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  font-weight: 900;
  letter-spacing: -0.03em;
  font-size: 1.15rem;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 42px;
  height: 42px;
  border-radius: 14px;
  color: white;
  background: linear-gradient(135deg, var(--leaf), var(--leaf-dark));
  box-shadow: 0 10px 24px rgba(78, 122, 77, 0.32);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1rem;
  font-weight: 700;
  color: var(--leaf-dark);
}

.nav-links a {
  text-decoration: none;
  opacity: 0.92;
}

.nav-links a:hover { opacity: 1; }

.nav-toggle {
  display: none;
  width: 46px;
  height: 42px;
  border: 1px solid var(--border);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.72);
}

.nav-toggle span:not(.sr-only) {
  display: block;
  height: 2px;
  width: 20px;
  margin: 4px auto;
  background: var(--ink);
  border-radius: 999px;
}