Edited css not working

Backlight Customization
#1

I edited 3.css to increase the font size from .75rem to 1.5rem as below.
fancybox-caption-collapsible .fancybox-caption
border: none;
box-sizing: border-box;
font-size: 1.50rem;
line-height: 1.5em;
margin: 0 auto;
min-height: 44px;
padding: 13px 48px;
text-align: center;

I saved it and copied it to https://lesmarmitonsnj.com/backlight/publisher/gallery/stylesheet/style/3

The change does not appear on the site. What did I do wrong?
It should look like this:

caption-size
caption-size1000×563 114 KB

Thanks,
Paul

#2

Use a custom stylesheet instead

Put the rules you need in a custom css file and upload that to backight/custom/css and then enable it in the page template under Advanced Setup: Custom Stylesheet