h1 {
  text-align: center;
}
ul {
  display: flex;
  list-style-type: none;
  margin: 50px 100px;
  font: 17px helvetica;
  text-align: center;
}

li {
  flex: 1;
  height: 66px;
  background: black;
}

li:hover {
  flex:1.1;
  transition:all .2s ease;
  background: #333333;
}

a {
  display: block;
  position: relative;
  text-decoration: none;
  color: white;
  padding: 23px;
}

.navigation li:not(:first-child){
	border-left: 2px solid #ecf0f1;