blockquote {border-left: 1px solid #eee; border-top: 1px solid #eee;}
body blockquote {margin: 0 2em;}
body blockquote blockquote {margin: 0 3em;}
blockquote h3,  blockquote blockquote h4 {margin-left: 0.75em;}
blockquote p {margin-left: 1.5em;}
blockquote pre {margin-left: 1.5em; color: inherit; background: #eee;}

blockquote blockquote blockquote {border: 1px solid #ddd; margin: 3em;}
blockquote blockquote blockquote p {margin: 0; color: inherit; background: #ffe;}
blockquote blockquote blockquote pre {margin: 0; color: inherit; background: #eee;}