body {
  padding: 150px;
  background-color: white;
}

.Selector {
  justify-content: center;
  align-items: center;
  height: 100vh;
  display: flex;
}

ul.menu {
  list-style-type: none;
  padding: 0px;
  margin: 0px;
  display: block;
}

ul.menu li {
  position: relative;
}

ul.menu li a {
  background-color: black;
  color: white;
  padding: 15px 10px;
  display: block;
  font-size: 18px;
  border-bottom: 2px solid white;
  text-align: center;
  width: 200px;
}

ul.menu li a:hover {
  background-color: darkgray;
}

ul.menu_lv1 {
  list-style-type: none;
  padding: 0px;
  margin: 0px;
  display: none;
  position: absolute;
  min-width: 100px;
  left: calc(100% + 5px);
  top: 0%;
}

ul.menu li:hover > .menu_lv1 {
  display: block;
}

ul.menu_lv2 {
  list-style-type: none;
  padding: 0px;
  margin: 0px;
  display: none;
  position: absolute;
  min-width: 100px;
  left: 100%;
  top: 0%;
}

ul.menu_lv1 li:hover > .menu_lv2 {
  display: block;
}