Best design practices are a group of different rules that in theory standardize web design, and in turn create a more consistent user experience.
CSS, or cascading style sheets, have been around for years. The trick was the different companies who develop browsers each had their own opinion on what constituted proper CSS. The W3C stepped in and provided a standard definition of this proper style. Thankfully most current browsers now render CSS properly, and we can develop sites using pure CSS.
This adds a powerful tool to the design toolbox. At Digitalus we do all of our design work using CSS. This creates flexible sites that can be updated site wide by simply changing one setting.
All of the sites that Digitalus develops are validated using the W3C validator service. This validation ensures that the sites will render properly on the widest range of browsers, and that they will not become obsolete as the standards are updated.