如何实现引导网格系统的功能。colx -“或“smallgrid”与foundation4?

I am looking to build a website in custom CSS and without frameworks just to increase my command over CSS. I want my entire site to retain its layout and look no matter what the device. Foundation does it with it's "smallgrid" and bootstrap with ".col-xs-". How do I do that without a framework?I am looking to build a website in custom CSS a