Remove the underline from hyperlinked images?

I’m currently redoing my entire site, starting with implementing the 2016 theme. Here’s my site: whiteRosesArt.com

I recently removed my image slider from the main page of my website in favor of static images. Those images have an annoying underline because they are linked. I’ve noticed that on the share buttons on all my pages & posts too. I can’t seem to figure out how to get rid of them.

In Style.css it already has

a {
color: #007acc;
text-decoration: none;

I’ve tried adding <text-decoration: none> to every line I can find that appears to have anything to do with hyperlinks (through the use of a child theme). I still have the underlines so clearly I’m not doing this right.

Can someone tell me what I’m doing wrong?

Thanks in advance!