What exactly do I do?

Boldly put, everything you see, and don’t see, on this website. The development (HTML, PHP, Javascript), the design (CSS), the graphics, the WordPress theme. But wait, pictures!

and it looks great on any screen

A responsive website is one that adapts to you so you can have a good time no matter what device you’re on. Don’t just trust me, test me! Go ahead and resize this window to any dimensions right now on your browser screen, and see how all this stuff reacts. No text gets too small. No items disappear. No evil horizontal scrollbar. That’s responsive.

Desktop Responsive Tablet Responsive Phone Responsive