Hi,

Please add these styles in Theme Options > Custom CSS:

#filters {
    margin: 0 auto;
    width: 1180px;
}
@media only screen and (max-width: 1466px) {
#filters {
    margin: 0 auto;
    width: 940px;
}
}
 @media only screen and (max-width: 1260px) {
#filters {
    margin: 0 auto;
    width: 860px;
}

}
 @media only screen and (max-width: 1024px) {
    
#filters {
    margin: 0 auto;
    width: 100%;
}

}

To set to font size also add this:

#filters li a {
    font-size: 34px;

}