suggested simplified wren css 

code=yes

<style>
body{
margin-top: 20px;
margin-right: auto;
margin-bottom: 40px;
margin-left: auto;
max-width:680px;
background:#fafafa;
line-height:1.6;
color:#333;
padding:0 10px 0 10px;
font-family: Verdana, Geneva, sans-serif;
font-size:20px;
}
h1{font-size: 30px;}
h1,h2,h3{line-height:1.2}
h3, h4 {
    padding-top: 20px;
    text-align: left;
    color: #000000;
}
h2 {
    margin: 20px 0 20px 0;
    font-size: 22px;
    color: #777;
    font-style: italic;
}
p{padding-top:10px;padding-bottom:10px;}
img {
    max-width: 100%;
}
blockquote {
    border-left: 1px solid #666;
    background: #f2f2f2;
    margin: 35px 0 35px .6em;
    padding: 0 0 0 1em;
}
code,
pre {
    font-size: 90%;
    background: #f8f8f8;
    padding: 2px 5px;
    border: 1px solid #ddd;
}

pre code {
    border: none;
    white-space: -moz-pre-wrap;
    white-space: pre-wrap;
    background: 0 0;
    padding: 0;
}
</style>