Template:Sidebar/styles.css

.sidebar {
	width: 22em;
	float: right;
	clear: right;
	margin: 0.5em 0 1em 1em;
	font-size: 88%;
}

@media (max-width: 640px) {
    .sidebar {
		width: 100% !important;
		clear: both;
		float: none !important;
		margin-left: 0 !important;
		margin-right: 0 !important;
	}
	
	.sidebar.nomobile {
		display: none;
	}
}