ul
{
  list-style-type: none;
  margin: 25;
  padding: 0;
  overflow: hidden;
  background-color: powderblue;
width: 90%;
}

lia
{
  float: left;
}

lia a
{
  display: block;
  color: white;
  text-align: center;
  padding: 15px 30px;
  text-decoration: none;
}

lia a:hover 
{
  background-color: SlateBlue;
}