I have declared the font-size directly on tags <a> and <div>.

If I insert that three tags on Font size custom selector, he overwrite the font-size of standard layout and use the font-size standard of body page.

I like to do it increase and decrease the font-size using the standard layout.

Example:
In my case I have title (first <a> tag) with 18px, the intro text (<div> tag) with 14px and read more (last <a> tag) with 10px.

When the user increase or decrease the font-size, I like to increase and decrease using the same proportion, not the same size of three tags.


P.S: thank you for the quick answer.