Editing Module:Infobox/styles.css

.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 https://phabricator.wikimedia.org/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 tr {
    display: table-row !important;
  }
  body.skin--responsive .infobox-table th,
  body.skin--responsive .infobox-table td {
    padding-left: inherit;
    padding-right: inherit;
  }
}