#content pre.code {
  background-color: #213449;
  background-image: url(/images/code-box-top-left.gif);
  background-position: top left;
  background-repeat: no-repeat;
  color: white;
  display: block;
  overflow: auto;
  width: 100%;
}
#content pre.code code {
  background-image: url(/images/code-box-bottom-right.gif);
  background-position: bottom right;
  background-repeat: no-repeat;
  display: block;
  font-family: "Lucida Console", Monaco, monospace;
  font-size: 115%;
  line-height: 135%;
  padding: 15px;
}

http://www.ruby-lang.org/stylesheets/high.css

Used for rounding corners of a div.  Need an upper left corner and an upper right corner.  Example page is http://www.ruby-lang.org/en/documentation/quickstart/

CSS Rounded corners

css, style

CSS