Responsive, flexible designs can make for complicated resizing -- after all there are a lot of elements on a page and scaling them all for different screen sizes isn't easy. But there's another ...

Building responsive websites means that your design has to adapt to different screen sizes. ... That is then applied using a series of media queries and the new CSS 3 unit rem.

If you’ve learned CSS from the ground up, you should have a good understanding of the box model. But if you’re unfamiliar ...