If you have the possibility of adding a class to those buttons, just add:
sf-button accent
Else, you can add the following custom css to the button class:
a.sf-button {
display: inline-block;
font-size: 12px;
line-height: 18px;
height: auto;
padding: 14px 16px;
margin: 0 10px 20px 0;
font-weight: bold;
-webkit-border-radius: 0;
-moz-border-radius: 0;
border-radius: 0;
-webkit-transition: all .3s ease-out;
-moz-transition: all .3s ease-out;
transition: all .3s ease-out;
border: 0;
position: relative;
overflow: hidden;
outline: none;
text-shadow: none;
text-decoration: none;
-moz-border-radius: 2px;
-webkit-border-radius: 2px;
border-radius: 2px;
-moz-background-clip: padding;
-webkit-background-clip: padding-box;
background-clip: padding-box;
vertical-align: middle;
max-width: 100%;
}
– Ed
.