pre{
    background-color: #EBECE4;
    overflow: auto;
}

a, a:visited {
text-decoration: none;
color: blue
}

a:hover {
color: red;
text-decoration: underline;}

h1 {
text-align: center;
border-bottom: 2px solid black;}

#content {
 margin-left: auto;
 margin-right:auto;
 max-width:  50em;
 overflow: hidden;
}

#sidebar {
    float:left;
    max-width:25em;
}