How to increase the font size for the visually impaired version?

Question

css

There is a site where everything is very bad with typography and layout. Everywhere different fonts and hardcoded types:
.article div span ain this project everything will be interrupted by one class that will be hung on the body and overwrite all the old styles.

And in theory what is a good practice for this? I mean, what if a version for the visually impaired was originally planned?

Answer 1

If all fonts are described in em , then it will be enough to change the font size on the root element (html/body).