You have this CSS that is causing a problem (can you remove it?):
@media (min-width: 991px) {
.ct-shortcode .searchandfilter > ul > li {
width: 16.66666667%;
}
}
@media (min-width: 768px) {
.ct-shortcode .searchandfilter > ul > li {
width: 33.33333333%;
}
}
But, my attempt:
.searchandfilter[data-sf-form-id="73587"] .sf-field-sort_order > ul > li.sf-option-active label {
background-color: #7DA85B;
color: #fff;
}
.searchandfilter[data-sf-form-id="73587"] .sf-field-sort_order input {
display: none;
}
.searchandfilter[data-sf-form-id="73587"] .sf-field-sort_order label:hover {
background-color: #7DA85B;
color: #fff;
cursor: pointer;
}
.searchandfilter[data-sf-form-id="73587"] .sf-field-sort_order label {
text-align: center;
line-height: 1.4em;
border: 1px solid #666;
border-radius: 3px;
padding: 3px 5px !important;
text-indent: 0;
}
.searchandfilter[data-sf-form-id="73587"] .sf-field-sort_order > ul > li {
display: inline-block;
margin-left: 5px;
margin-bottom: 10px;
}
A start at least, change as you need.