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CSS CSS Foundations Values and Units Relative Length Units

Toni Caktas
Toni Caktas
16,478 Points

how do I do this with rem?

Simple explanation how does the rem unit work...don't quiet get it?

1 Answer

Great question! 1rem is equal to the font-size specified or defaulted to in the root of the document. For example:

html {
    font-size: 20px;

h1 {
    font-size: 1rem

p {
    font-size: 0.7rem

Now, because 20px is the font-size specified in html (or root), 1rem will be equal to 20px. In p, font-size is set to 0.7rem, or 70% of 20px, which will equate to 14px.

For a more detailed look at why and how you'd use rem units, look here: http://css-tricks.com/rems-ems/