First we would remove the background color and add it to:
.shareaholic-share-buttons-container .shareaholic-share-buttons-wrapper {
background-color: #f2f0f0;
}
Now let’s add some width:
.shareaholic-share-buttons-container .shareaholic-share-buttons-wrapper {
background-color: #f2f0f0;
width: 100%;
}
and the last step is to remove the padding from the icons itself
.shareaholic-share-buttons-container ul.shareaholic-share-buttons {
padding: 0;
}
Final results: https://i.imgur.com/IBBU7lx.png