CSS fonts rem trick: 62.5% or 6.25%

Question

I would like to use font sizing with REM and on internet I found following trick:

html { font-size: 62.5%; } 
body { font-size: 1.4rem; } /* =14px */
h1   {          


        

Answer 1

You can also use pixels - the default font-size is 16px by default, setting 10px as a base allows you to use rems whereby 1rem = 10px because the root is set as 10px.

html { font-size: 10px}
body { font-size: 1.4rem; } /* =14px */
h1   { font-size: 2.4rem; } /* =24px */