Dynamically Adjust Font Sizes WIth CSS/HTML...?

[StaticS]

Okay, I'm trying to make a webpage for a grade ten project without the use of an editor. I have to get it to scale between different resolutions. I have already made the images scalable (if that's a word), but the fonts stay the same size! Can someone give me a way to apply (%) values to fonts so they can scale in size? Thanks. Oh, and the code has to be either CSS or HTML.