.accordion .wpgb-facet-title {
    position: relative;
}

.accordion .wpgb-facet-title::after{ 
    content: "";
    display: inline-block;
    position: absolute;
    right: 0;
    padding: 6px;
    margin-top: 6px;
    border: solid #000;
    border-width: 0 2px 2px 0;
    transform: rotate(225deg);
    transition: 0.25s;
}

.accordion.closed .wpgb-facet-title::after {
    transform: rotate(45deg);
    margin-top: 0px;
}

.accordion legend,
.accordion.closed fieldset  {
    display: none;
}