Changing font size for heading 1, 2,3 etc?

Hi. I find the sizes of the headings to be too similar, is there a way to change the size of the fonts? I took a look at the style.css under font size and it looks like the font sizes are 24, 22, 20 etc. for the headings. Is that correct? Can I just change the numbers to something like 32, 26, 20 etc. and save? Thank you!