body{
  background-image: url('background.jpg');
  background-size: cover;
  font-family: Verdana;
  font-size: 20px;
  margin: 0;
  line-height: 4px;
}
.navbar{
  text-align: center;
  width: 100%;
  background: blue;
  opacity: 0.6;
}
.navbar ul {
  margin: 0;
  padding: 0;
  list-style: none;
  position: relative;
}
.navbar ul li a {
  display: block;
  padding: 25px;
  color: white;
  text_decoration: none;
  width: 150px;
}
.navbar ul:after {
  content: ""; clear: both;
  display: block;
}
.navbar ul li {
  float: left;
  list-style: none;
}
.navbar ul ul {
  display:none;
}
.navbar ul li:hover > ul{
  display: block;
}
.navbar ul li:hover {
  background: black;
  transition: 0.1s;
}
.navbar ul ul {
  background: black;
  padding: 0;
  margin: 0;
  list-style: none;
  position: absolute; top:100%;
}
.navbar ul ul li {
  float: none;
  position: relative;
}
.navbar ul ul li a {
  padding: 25px;
  color: white;
  width: 150px;
  text-align: left;
}
.navbar ul ul li a:hover {
  background: lightblue;
  color: black;
  transition: 0.1s;
}