About Font-size

See an article thinking good, record it down. Original Address https://css-tricks.com/rems-ems/

REM (root em), also a relative length unit, differs from EM by the font-size of the root element, thus avoiding the trouble caused by the EM cascade effect. So many people started using REM layouts.

{ font-size:}{ font-size:}{ font-size:}  { font-size:}

Ideally, you can resize the page by simply adjusting the font-size value in the HTML. In fact, the effect is not ideal, some parts will be too large, and some of the handwriting will be small to illegible.

This led to the idea thatpx at the Root, REM for components, and EM for actual elements.

Change to html{font-size:100%} would be a little better

About Font-size