Social sharing buttons are usually a huge pain in my experience, and especially if you’re using the default styles that come in with the snippet (it looks like you’re using AddThis, maybe?) Sometimes spacing is funky, and you end up fighting against it a bunch.
To combat it, I usually do one of the following:
I look to see if the site that provided the snippet (places like AddThis, etc) offer a version that is unstyled, and it’s much easier to make them do what you want.
Or, I have to resort to what has been mentioned above: Tweak specific buttons that aren’t playing nice. Some of the time it ends up meaning changing stuff inline, or throwing !important at it (which is kind of gross, and feels dirty). Sometimes it’s the only way though.