.nav-demo {
  background: #34495e;
  padding: 0;
  margin: 20px 0;
  border-radius: 8px;
  overflow: hidden;
}

.nav-demo ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
}

.nav-demo li {
  flex: 1;
}

.nav-demo a {
  display: block;
  padding: 15px 20px;
  color: white;
  text-decoration: none;
  text-align: center;
  transition: background-color 0.3s ease, transform 0.2s ease;
  position: relative;
}

.nav-demo a:hover {
  background-color: #3498db;
  transform: translateY(-2px);
}

.nav-demo a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 3px;
  background-color: #e74c3c;
  transition: width 0.3s ease, left 0.3s ease;
}

.nav-demo a:hover::after {
  width: 100%;
  left: 0;
}