The "new" datatracker uses Twitter Bootstrap for the UI. Get familiar with http://getbootstrap.com/getting-started/ and use those UI elements instead of cooking up your own. We have some site-wide customization applied to the bootstrap version we keep in bootstrap/ (from which the minified dist version is built); it modifies some stuff under less/ We also apply some additional custiomizations in static/css/ietf.css; we should eventually move that under bootstrap/less/ if possible. (ietf.css was what Lars used initially for customization with an unmodified bootstrap.) Some ground rules: * Think hard before tweaking the bootstrap CSS, it will make it harder to upgrade to future releases. * No