CSS makes repetitive tagging easier, so start out with something simple that will save time – Formatting Text – but do it properly and use ‘ems’.
body { font-size:62.5%} /* Reduce DEFAULT font size */
h1 {font-size:2em;} /* font displayed at 24px */
h2 {font-size:1.5em;} /* font displayed at 18px */
h3 {font-size:1.25em;} /* font displayed at 15px */
h4 {font-size:1em;} /* font displayed at 12px */
p, a, li, {font-size:1em;} /* font displayed at 12px */