body{
    background-image: url(./bach3.jpg);
    width: 100%;
    height: 100%;
}

ul{
    margin: 0px;
    padding: 0px;
    
    
}

ul li{
float: left;
list-style: none;
}
ul li a{
text-decoration: none;
width: 200px;
height: 30px;
background-color:transparent;
color:olive;
display: inline-block;
text-align: center;
line-height: 30px;
transition: 1s;
font-weight: 900;
border-radius: 10px;

}
ul li a:hover{
    background-color:white;
    color:black;

}

iframe {
  display: block; 
  margin-left: auto;
  margin-right: auto;
}