Editing Module:Infobox/styles.css

/* {{pp|small=y}} */
/*
 * This TemplateStyles sheet deliberately does NOT include the full set of
 * infobox styles. We are still working to migrate all of the manual
 * infoboxes. See [[MediaWiki talk:Common.css/to do#Infobox]]
 * DO NOT ADD THEM HERE
 */
/*
 * not strictly certain these styles are necessary since the modules now
 * exclusively output infobox-subbox or infobox, not both
 * just replicating the module faithfully
 */
.infobox-subbox {
	padding: 0;
	border: none;
	margin: -3px;
	width: auto;
	min-width: 100%;
	font-size: 100%;
	clear: none;
	float: none;
	background-color: transparent;
}

.infobox-3cols-child {
	margin: auto;
}

.infobox .navbar {
	font-size: 100%;
}

/* Dark theme: [[William_Wragg]], [[Coral_Castle]] */

@media screen {
    html.skin-theme-clientpref-night .infobox-full-data:not(.notheme) > div:not(.notheme)[style] {
	    background: #1f1f23 !important;
	      /* switch with var( --color-base ) when supported. */
	      color: #f8f9fa;
	}
}


@media screen and ( prefers-color-scheme: dark) {
    html.skin-theme-clientpref-os .infobox-full-data:not(.notheme) div:not(.notheme) {
      background: #1f1f23 !important;
      /* switch with var( --color-base ) when supported. */
      color: #f8f9fa;
    }
}


/* Since infobox is a table, many infobox templates take advantage of this to
 * add columns and rows to the infobox itself rather than as part of a new table
 * inside them. This class should be discouraged and removed on the long term,
 * but allows us to at least identify these tables going forward
 * Currently in use on: [[Module:Infobox3cols]]
 * Fixes issue described in [[phab:F55300125]] on Vector 2022.
*/
@media (min-width: 640px) {
  body.skin--responsive .infobox-table {
    display: table !important;
  }
  body.skin--responsive .infobox-table > caption {
    display: table-caption !important;
  }
  body.skin--responsive .infobox-table > tbody {
    display: table-row-group;
  }
  body.skin--responsive .infobox-table th,
  body.skin--responsive .infobox-table td {
    padding-left: inherit;
    padding-right: inherit;
  }
}