.nav-demo {
  background-color: #2c3e50;
  padding: 20px;
  border-radius: 8px;
  position: relative;
  overflow: hidden;
}

.nav-menu {
  display: flex;
  list-style: none;
  margin: 0;
  padding: 0;
  gap: 30px;
  justify-content: center;
  flex-wrap: wrap;
}

.nav-item {
  position: relative;
}

.nav-link {
  color: #ecf0f1;
  text-decoration: none;
  padding: 10px 0;
  font-weight: 500;
  position: relative;
  transition: color 0.3s ease;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, #3498db, #2ecc71);
  transition: width 0.4s ease;
  transition-delay: 0.1s;
}

.nav-link:hover {
  color: #3498db;
}

.nav-link:hover::after {
  width: 100%;
}

.dropdown {
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%) translateY(10px);
  background: white;
  min-width: 200px;
  border-radius: 8px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.2);
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  transition-delay: 0s;
  z-index: 1000;
}

.nav-item:hover .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
  transition-delay: 0.2s;
}

.dropdown-item {
  display: block;
  padding: 12px 20px;
  color: #2c3e50;
  text-decoration: none;
  transition: background-color 0.2s ease;
  border-radius: 4px;
  margin: 4px;
}

.dropdown-item:hover {
  background-color: #f8f9fa;
}