Nicholas Zakas and Nicole Sullivan released a really great tool called CSS Lint which according to its authors:

CSS Lint is a tool to help point out problems with your CSS code. It does basic syntax checking as well as applying a set of rules to the code that look for problematic patterns or signs of inefficiency. The rules are all pluggable, so you can easily write your own or omit ones you don’t want.

The project is open source and available at github.

At some point in a project you might have used a slider of images for e.g. your featured articles or something. While there are literally hundreds of these out there, Flux goes a step further and while browser support is not the best, have a look at it as it utilizes some really great CSS3 effects. As the author states, you can either use jQuery or Zapto.js. In order to view the demo you need a browser that supports CSS3 transitions. Good stuff.