element.style {
}
.btn:first-child {
}
button.btn, input[type=submit].btn {
}

.btn-primary {
    color: #fff;
    background-color: #000000;
    border-color: #ffffff #ffffff #000000;
    border-color: rgba(0, 0, 0, .0) rgba(0, 0, 0, .0) rgba(0, 0, 0, .25);

}
.modal-footer .btn+.btn {
    margin-left: 5px;
    margin-bottom: 0;
}
.btn-toolbar>.btn+.btn, .btn-toolbar>.btn-group+.btn, .btn-toolbar>.btn+.btn-group {
    margin-left: 5px;
}
<style>
.site-footer .btn-default {
    color: #000000 !important;
}
.site-footer .btn {
    display: inline-block;
    padding: 4px 12px;
    margin-bottom: 0;
    font-size: 14px;
    line-height: 20px;
    text-align: center;
    vertical-align: middle;
    cursor: pointer;
    color: #fff;
    text-shadow: 0 1px 1px rgba(255, 255, 255, .75);
    background-color: #ffffff;
    background-image: none;
    background-repeat: no-repeat;
    border: 0;
    -moz-border-radius: 4px;
    border-radius: 4px;
    -moz-box-shadow: inset 0 1px 0 rgba(255,255,255,.2),0 1px 2px rgba(0,0,0,.05);
    box-shadow: none;
}