Codeblock/styles.css

.codeblock-title {
	padding: 2px 0;
}

.codeblock {
	border-top: 2px solid #f0f0f0;
	border-right: 2px solid #f0f0f0;
}

.codeblock.mw-collapsed {
	max-height: calc(10em * 1.25);
	overflow-y: hidden;
	position: relative;
}

.codeblock-clip-toggle {
	background: #f0f0f0; 
	color: #72777d;
	padding: 2px 0;
	border-top: 2px solid #f8f8f8;
	width: 100%;
	height: 1.25rem;
	font-size: 80%;
	display: flex;
	justify-content: center;
	align-items: center;
	box-sizing: border-box;
}

.mw-collapsed .codeblock-clip-toggle {
	position: absolute;
	top: calc(9rem * 1.25);
}