Most Ruby developers use Rails for their everyday projects. Often they toy around with front-end themselves or outsource it, ending up tangled in a web of css-all-over-the-place.
Keeping your front-end code clean is hard. Before you know it you're suffering from CSS specificity issues and not-really-generic partials. Find out how to keep things tidy using the HTML5 document outline and modular Sass & CoffeeScript, for truly reusable code.