How to change the button alignment

Use the following custom css in Mashshare->settings->Visual->custom css:

Align the buttons to the right:

.mashsb-container {
width:100%;
float: right;
}

Align the buttons to the left (default):

.mashsb-container {
width:100%;
float: left;
}

Center alignment of the buttons:

.mashsb-container {
width:500px; /* Must be the total width of the buttons */
margin:0 auto;
}