Add this to custom-fields-accordions.scss.css

custom-fields-accordions.scss.css

#custom-fields-accordion .accordion, .accordion * {
  -webkit-box-sizing:border-box; 
  -moz-box-sizing:border-box; 
  box-sizing:border-box;
}

#custom-fields-accordion .accordion-section {
  border-top: 1px solid #dcdcdc;
  position: relative;
}

#custom-fields-accordion .accordion-section:last-child {
  border-bottom: 1px solid #dcdcdc;
}

#custom-fields-accordion .accordion-section-content {
  display:none;
  padding-bottom: 15px;
}

#custom-fields-accordion .accordion-section-title {
  width:100%;
  display:inline-block;
  font-size:1.200em;
  border: 0 !important;
  padding: 0px;
  line-height: 3;
}

#custom-fields-accordion a.accordion-section-title:after {
  width: 8px;
  height: 8px;
  border-right: 1px solid #4a6e78;
  border-bottom: 1px solid #4a6e78;
  position: absolute;
  right: 10px;
  content: " ";
  top: 25px;
  transform: rotate(-45deg);
  -webkit-transition: all 0.2s ease-in-out;
  -moz-transition: all 0.2s ease-in-out;
  transition: all 0.2s ease-in-out;
}

#custom-fields-accordion a.active.accordion-section-title:after {
  transform: rotate(45deg);
  -webkit-transition: all 0.2s ease-in-out;
  -moz-transition: all 0.2s ease-in-out;
  transition: all 0.2s ease-in-out;
}