This is an informative card that will tell you something that's... well, important!
A little, nifty way of putting in an alert. Hover over it to see the message. There are some code bits in the 'head' box on the Element pane that makes the clipping of the actual box, leaving just the round button behind. This cannot be seen when working in the app, but it will be seen when previewing.
Unfortunately, in IE11 the mentioned clippinng will not work, so the full alert will be displayed. There are also some problems on mobile devices with Safari. Therefore there is a second component which will display the full alert and only collapse on screen widths of 800px and above.
On mobile devices you won't get the hover colour since hovering is not possible.