<!DOCTYPE html>
<html>
<head>
<style>
* {
box-sizing: border-box;
}
body {
margin: 0;
}
.header {
background-color: #2196F3;
color: white;
text-align: center;
padding: 15px;
}
.footer {
background-color: #444;
color: white;
padding: 15px;
}
.topmenu {
