If you've heard about htaccess and it sounds like it does what you want, but you're not sure how it works... well, you're in the right place. Read on.
#1. It's a file and its filename is .htaccess (yes, with a dot in the front).
Learn how to create flexible layouts using relative units in CSS. New relative units added in CSS3 include vw(viewports width), vh(viewports height), vmin(minimum of viewports height and width), and vmax (maximum of viewports height and width).