<style type="text/css" media="screen">
html{width: 85%; min-width: 600px;margin: 0 auto; font-family: sans-serif;}
h1,h2,h3,h4,h5,h6{border:0!important;}
h1{font-size:170%!important;border-top:4px solid #aaa!important;padding-top:.5em!important;margin-top:1.5em!important;}
h1:first-child{margin-top:0!important;padding-top:.25em!important;border-top:none!important;}
h2{font-size:150%!important;margin-top:1.5em!important;border-top:4px solid #e0e0e0!important;padding-top:.5em!important;}
h3{margin-top:1em!important;}
p{margin:1em 0!important;line-height:1.5em!important;}
ul{margin:1em 0 1em 2em!important;}
ol{margin:1em 0 1em 2em!important;}
ul ul, ul ol, ol ol, ol ul{margin-top:0!important;margin-bottom:0!important;}
blockquote{margin:1em 0!important;border-left:5px solid #ddd!important;padding-left:.6em!important;color:#555!important;}
dt{font-weight:bold!important;margin-left:1em!important;}
dd{margin-left:2em!important;margin-bottom:1em!important;}
table{margin:1em 0!important;}
table th{border-bottom:1px solid #bbb!important;padding:.2em 1em!important;}
table td{border-bottom:1px solid #ddd!important;padding:.2em 1em!important;}
pre{margin:1em 0!important;font-size:90%!important;background-color:#f8f8ff!important;border:1px solid #dedede!important;padding:.5em!important;line-height:1.5em!important;color:#444!important;overflow:auto!important;}
pre code{padding:0!important;font-size:100%!important;background-color:#f8f8ff!important;border:none!important;}
code{font-size:90%!important;background-color:#f8f8ff!important;color:#444!important;padding:0 .2em!important;border:1px solid #dedede!important;}
</style>
This file is a great place to start when you're adding Markdown documentation to your next project. When converted into HTML, this Markdown file contains the CSS that GitHub uses for viewing Markdown pages.
Check out the raw source to see.
That looks pretty nifty!