html {
  height: 90%;
  box-sizing: border-box;
}

*,
*:before,
*:after {
  box-sizing: inherit;
}

body {
    min-height: 100%;
    position: relative;
    background-color: #f;
    color: #0;
    margin:1em auto;
    max-width:40em;
    padding:0 .62em;
    font:1.2em/1.62em sans-serif;
}
h1 {
    text-align: center;
    line-height: 1.8cm;
}
aside {
    text-align: center;
}
h2 {
    line-height: 1.8cm;
}
h3 {
    line-height:1.2em;
}
footer {
    position: absolute;
    bottom: 0;
}
@media print{
    body{
        max-width:none;
    }
}