.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-line);
  padding: 0.75rem 3%;
  min-height: 4.25rem;
}

.site-logo {
  text-decoration: none;
  color: var(--color-ink);
  margin-right: 2rem;
}

.site-logo-mark {
  width: 2.25rem;
  height: 2.25rem;
}

.site-logo-name {
  font-family: 'Playfair Display', Georgia, serif;
  font-size: 1.45rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--color-ink);
}

.site-nav {
  margin-left: auto;
}

.site-nav .site-nav-list {
  align-items: center;
}

.site-nav .nav-link {
  font-weight: 600;
  font-size: 1rem;
  color: var(--color-ink);
  text-decoration: none;
  border-radius: 0.5rem;
  transition: color 0.2s ease, background-color 0.2s ease;
}

.site-nav .nav-link:hover,
.site-nav .nav-link:focus-visible {
  color: var(--color-leaf);
  background: var(--color-mint);
}

.site-nav .nav-link-order {
  color: var(--color-leaf);
}

.has-mega .nav-link::after {
  content: "";
  display: inline-block;
  width: 0.45em;
  height: 0.45em;
  margin-left: 0.4em;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: translateY(-0.2em) rotate(45deg);
}

.mega-panel {
  position: absolute;
  left: 0;
  right: 0;
  top: 100%;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
  padding: 1.5rem 4%;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-line);
  box-shadow: 0 18px 30px rgba(29, 38, 34, 0.1);
  visibility: hidden;
  opacity: 0;
  transition: opacity 0.2s ease, visibility 0s linear 0.2s;
}

.has-mega:hover .mega-panel,
.has-mega:focus-within .mega-panel {
  visibility: visible;
  opacity: 1;
  transition-delay: 0s;
}

.site-nav .mega-panel .mega-link {
  display: block;
  padding: 1rem;
  border-radius: 0.9rem;
  border: 1px solid var(--color-line);
  text-decoration: none;
  color: var(--color-ink);
  font-size: 1rem;
  background: var(--color-paper);
  transition: border-color 0.2s ease, background-color 0.2s ease;
}

.site-nav .mega-panel .mega-link:hover {
  border-color: var(--color-leaf);
  background: var(--color-mint);
  color: var(--color-ink);
}

.mega-title {
  display: block;
  font-weight: 700;
  margin-bottom: 0.2rem;
}

.mega-note {
  display: block;
  font-size: 0.9rem;
  color: var(--color-muted);
}

.site-toggle {
  margin-left: auto;
  width: 2.75rem;
  height: 2.75rem;
  align-items: center;
  border-radius: 0.6rem;
}

.site-toggle span {
  border-radius: 2px;
  width: 1.5rem;
}

.site-nav-close {
  width: 2.75rem;
  height: 2.75rem;
  color: var(--color-ink);
}

@media (max-width: 767px) {
  .site-header { padding: 0.6rem 4%; min-height: 3.75rem; }
  .site-logo { margin-right: 0; }
  .site-logo-name { font-size: 1.3rem; }
  .site-nav .site-nav-list { align-items: stretch; }
  .site-nav .nav-link { font-size: 1.05rem; border-radius: 0; }
  .site-nav .nav-link:hover { background: transparent; }
  .has-mega .nav-link::after { display: none; }
  .mega-panel {
    position: static;
    visibility: visible;
    opacity: 1;
    grid-template-columns: minmax(0, 1fr);
    gap: 0.4rem;
    padding: 0.5rem 0 0.9rem 0.8rem;
    box-shadow: none;
    border-bottom: 1px solid var(--color-line);
    background: transparent;
  }
  .site-nav .mega-panel .mega-link {
    padding: 0.45rem 0;
    border: 0;
    background: transparent;
    font-size: 0.95rem;
  }
  .mega-note { display: none; }
}