.panel-heading[role="tab"] .panel-title > a {
        position: relative;
        display: block;

        width: 100%;
      }

      .panel-heading[role="tab"] .panel-title > a.collapsed::after, .panel-heading[role="tab"] .panel-title > a::after {
        content: '';

        position: absolute;

        right: 1em;
        top: 50%;

        width: 0.75em;
        height: 0.75em;

        border-bottom: 0.25em solid #ABABAB;
        border-right: 0.25em solid #ABABAB;
        transform: translateY(-50%) rotate(45deg);
        transition: transform 0.2s ease;
      }

        .panel-heading[role="tab"] .panel-title > a::after {
          transform: translateY(-50%) rotate(45deg);
        }

        .panel-heading[role="tab"] .panel-title > a.collapsed::after {
          transform: translateY(-50%) rotate(-45deg);
        }