Simple.css
Simple.css is a classless CSS template to make a good website
... for the Bootstrap framework is 144KB in total. By comparison, Simple.css is around 4KB. Obviously Simple.css and Bootstrap don’t compare in terms of their functionality, but Simple.css allows website developers to spin something up very quickly that looks good and needs very little work. By using something like Simple.css, provides the basics to get up and running quickly (or just use it as-is for a simple, good-looking site) yet not have to learn an extremely convoluted framework.