Frame of uploaded pictures

Hi,

as you can see when you click on my website link, there is an ugly frame around the logo.. and I’m not sure if there are frames around the three pictures below or just my hurting eyes ?? I really want to make the frame(s) disappear.
https://www.bagfullofsun.de

.header-image img, .entry-content img, .comment-content img, .widget img, .entry-thumbnail img { border: 0; }

and

img { border: 0 none !important; }

didn’t work in the CSS Box.