optimize css

[olets]

Refactors CSS, optimizes some styles, drops the borders (see #47). 1/3 reduction!

• now the buttons are 2px narrower and 2px shorter. To keep them the old size, could do css/modules/_share-buttons.css:166 padding: calc(0.5em + 2px) calc(0.75em + 2px);
• dropped the :hover, :active, and :focus styles from .resp-sharing-button__link. If you want to make sure other styles like a:hover {color: #000} don't mess things up, could add !important to _share-buttons:css:8, 9, and 10

[mxstbr]

Awesome, this is great! Thanks so much!

[mxstbr]

could add !important to _share-buttons:css:8, 9, and 10

Let's discuss in this issue: #49