Codeblock/styles.css

.template-source.mw-collapsed.clip .mw-highlight {
	max-height: calc(9em * 1.25);
	overflow-y: hidden;
}

.template-source-toggle {
	background:#f0f0f0; 
	color:#72777d;
	padding: 2px 0;
	border-top: 2px solid #f8f8f8;
}