WordPress: Multiline site title instead of tagline

I found it hard to change the layout of the tagline in my WordPress Twentyfourteen child theme as the element sits in a different hierarchy. But fortunately we can add text also from the CSS stylesheet (which is not visible in the sourceode!) using the content tag. It does not accept standard HTML while the special formatting is shown on stackoverflow.

.site-title :after {
	font-size: 25px;
    content: "\00000aBut let your communication be Yea, yea;\00000aNay, nay: for whatsoever is more than these cometh of evil";
    white-space: pre;

The reason for that? Just a quick fix.