If you ever wanted to code (only CSS) on your site from anywhere, you can now do this using WebPutty. This hosted service is a simple CSS editing application which gives you a syntax-highlighting CSS editor, lets you use the power of SCSS and Compass, provides a side-by-side preview panel, instant publishing with minification, compression and automatic cache-control.
Main features include instant preview which is provided side-by-side, therefor is no need to switch between browser and editor to see your changes. Also, as mentioned above you can use the power of SCSS (SCSS gives you expanded functionality and ease-of-use features (nested selectors, variables, mixins) and Compass (makes features like box-shadow, border-radius, gradients, transforms, etc easier to implement by handling all the browser-specific prefixes for you).
simple and powerful web CSS editor: Preview