Confluence Cloud change font size of div in PDF Export

I have some content wrapped in a div macro that I am trying to set to a smaller font size. (8pt) I have already added this to the PDF Export Stylesheet to control the font of the whole document and it works correctly:

body,p,li,td,table,tr,.bodytext,.stepfield {
    font-size: 11pt;
}

But I cannot get this to work at all:

div.smalltext {
    font-size: 8pt;
}

This does work however:

div.smalltext {
    display: none;
}

so I think I am selecting it correctly there must just be something with the font I do not understand?

What is even stranger is that it is affecting the display in Confluence as if I had added it to the stylesheet for this space and not the PDF stylesheet...??????? The content inside of my div.smalltext is displaying in my browser at a smaller font size but when I export it goes back to the standard size font.

Since I cannot post more than one comment or question per day I will add to my original question:

I tried:

div.smalltext {
    font-size: 80%;
}

and also using em. The only way I can get it to work is by changing my previous code:

body,p,li,td,table,tr,.bodytext,.stepfield {
    font-size: 11pt;
}

to n% or nem. Then the div.smalltext works correctly. I think I understand what you mean by fixed size and surrounding text but I tried setting the div.smalltext font-size value from 8pt all the way to 20pt and the size of the text still did not change...