body{
    margin: 10;
    padding: 10;
    font-size: 15px;
    background-color: #333;
}
 
nav {
    background-color: #333;
    margin: auto;
    
    width: 100%;
}

nav ul{
    margin: auto;
    padding: 0;
}
nav ul li {

    display: inline-block;
    list-style-type: none;
    margin-bottom: 10px;
}
 

nav > ul > li > a {
    color: #aaa;
    background-color:#000;
    display: block;
    line-height: 2em;
    padding: .5em .5em;
    text-decoration: none;
	font-family: Arial;
	text-align: center;
}
 
h1{
color: white;
text-align: center;
font-family: Helvetica;
font-size: 35px;
}

h2{
color: white;
text-align: center;
font-family: Helvetica;
font-size: 25px;
}

h3{
color: white;
text-align: center;
font-family: Helvetica;
font-size: 15px;
position: sticky;
top: 15px;
}

li a:hover {
  background-color: #555;
font-size: 25px;
}

div
{
margin: auto;
text-align: center;
}