.main-nav ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.main-nav li {
  margin-bottom: 5px;
}

.menu-toggle {
  background: none;
  border: none;
  font-size: 16px;
  cursor: pointer;
}

.submenu {
  display: none;
  margin-left: 20px;
}

.is-open > .submenu {
  display: block;
}