Hi,
I’m not sure how that site is doing it, but on a number of my sites, I’ve done something similar, either at the top, like here vidyablog.com, or at the bottom. They are created with plugins. I’ve used WP Front Notification Bar which is the one on that site, but lately I’ve preferred GC Message Bar. Both are good and both could be stationary or can be animated, etc. You can create styles with CSS so they look however you want.