about button icons

css/components/islandora_mods.css

@@ -506,22 +506,26 @@ form#views-exposed-form-newspapers-view-block-1 div#edit-actions {
   font-family: var(--font-sans);
 }
 .field--name-field-contributor-details summary::before {
+  content: "▶";
   content: "▶";
   display: inline-block;
   margin-right: 0.5em;
 }
 
 .field--name-field-contributor-details details[open] summary::before {
+  content: "▶";
   content: "▶";
   transform: rotate(90deg);
 }
 summary.about.button::before {
+  content: "▶";
   content: "▶";
   display: inline-block;
   margin-right: 0.5em;
 }
 
 details[open] summary.about.button::before {
+  content: "▶";
   content: "▶";
   transform: rotate(90deg);
 }