Basic Horizontal Menu

.menu {
  display: flex;
  gap: 1.5rem;
  list-style: none;
  padding: 0;
  margin: 0;
}

.menu li a {
  color: var(--color-gray-700);
  text-decoration: none;
  padding: 0.5rem 1rem;
  transition: color 0.2s ease;
}

.menu li.active a {
  color: var(--color-primary-600);
}

.menu li a:hover {
  color: var(--color-primary-600);
}

Mega Menu

.mega-menu {
  position: absolute;
  left: 0;
  width: 100%;
  background: white;
  box-shadow: var(--shadow-lg);
  padding: 2rem;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

.mega-menu-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
}

.has-mega:hover .mega-menu {
  opacity: 1;
  visibility: visible;
}