body{
 text-align: center; 
 color: white;
 margin-left: 15%;
 margin-right: 15%;
}
p{
  background-color: black;
}
h2{
 color: white;
 background-color: black;
}

h1{
 color: white;
 background-color: black;
}
nav ul {
  list-style-type: none;

}
/*Remove line breaks.*/
nav ul li {
 float: left;
 margin-right: 0.5em;
}

/*change the style of the links (<a>s). */
nav ul li a{
 text-decoration: none;
 color: black ;
 background-color: aquamarine;
 border: 2px solid #000000;
 padding: 0.25em 0.75em 0.25em 0.75em;
}

nav{
  display:grid;
  place-content: center;
}
body {
 background-image: url("../images/pong.jpg");
 background-color: #cccccc; 
 background-size: cover;
}