<html>
<head>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<style>
* {
box-sizing: border-box;
}
.menu {
float:left;
width:20%;
text-align:center;
}
.menu a {
background-color:#e5e5e5;
padding:8px;
margin-top:7px;
display:block;
width:100%;
color:black;
}
.main {
float:left;
width:60%;
padding:0 20px;
}
.right {
background-color:#e5e5e5;
float:left;
width:20%;
padding:15px;
margin-top:7px;
text-align:center;
}
@media only screen and (max-width:620px) {
/* For mobile phones: */
.menu, .main, .right {
width:100%;
}
}
</style>
</head>
<body style="font-family:Verdana;color:#aaaaaa;">
<div style="background-color:#e5e5e5;padding:15px;text-align:center;">
<h1>Hello World</h1>
</div>