Images auto margin/ padding?!?

Hello, I am creating my own theme for my WordPress blog and decided to to place social media icons in the sidebar, however they seem to be automatically spacing themselves apart, but only in some browsers. (I am aware of the 1px gap!) Is there a fix?? It might just be with my code but I can’t spot it. I can think of a few fixes but I’d rather do it properly. Here is my code.

[Mod Note: Chunk of code removed. If you want to post large blocks of code, please use a pastebin.]