styles.css

.bs-collapsible {margin-bottom:0.5em}
.bs-collapsible h3 {background:#f1f3f9; border-bottom:1px solid 	#d8d8d9;font-size:1em; padding:8px 4px; margin:0; font-weight:normal; border-radius:4px}
.bs-collapsible > div > h3::before {font-family:bootstrap-icons !important; vertical-align:middle; margin-right:8px}
.bs-collapsible > div[aria-expanded="false"] > h3::before { content:"\F285";}
.bs-collapsible > div[aria-expanded="true"] > h3::before { content:"\F282";}
.bs-collapsible .mw-collapsible-content {border-left:4px solid #d8d8d9; margin-left:10px; padding:10px 20px}