I'm trying to support SVGs where I can, and I have a PNG image fallback for email clients that don't support SVG. I'm using the method described here: https://css-tricks.com/a-guide-on-svg-support-in-email/#svg-email-bonus

It's working pretty great so far, but my problem is that the SVG that's being hidden(or compressed with width/height:0) is showing a border of some sort:

Hidden SVG border

I've put border:0, border-style:0 everywhere I can see or think of in Inspector to find what's causing this, but nothing's worked. Any ideas out there?