/* Site header & navigation */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(248, 247, 244, 0.95);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  transition: box-shadow 0.3s var(--ease-out);
}

.site-header.scrolled {
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.06);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-md);
}

.logo {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: -0.02em;
}

.logo img {
  height: 2.25rem;
  width: auto;
  object-fit: contain;
}

.logo:hover {
  color: var(--color-primary-dark);
}

.logo:hover img {
  opacity: 0.9;
}

.nav-toggle {
  display: none;
  padding: var(--space-sm) var(--space-md);
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text);
  font-size: 1.25rem;
}

.nav-list {
  display: flex;
  align-items: center;
  gap: var(--space-xl);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-list a {
  font-weight: 500;
  color: var(--color-text);
  position: relative;
  transition: color 0.25s var(--ease-out);
}

.nav-list a::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width 0.3s var(--ease-out);
}

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

.nav-list a:hover {
  color: var(--color-primary);
}

@media (max-width: 768px) {
  .nav-list a::after {
    display: none;
  }
}

.nav-list a[aria-current="page"] {
  color: var(--color-primary);
  font-weight: 600;
}

@media (max-width: 768px) {
  .nav-toggle {
    display: block;
  }

  .nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-lg);
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: transform var(--transition-base), opacity var(--transition-base),
      visibility var(--transition-base);
  }

  .nav.is-open {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav-list li {
    border-bottom: 1px solid var(--color-border);
  }

  .nav-list li:last-child {
    border-bottom: none;
  }

  .nav-list a {
    display: block;
    padding: var(--space-md);
  }
}