A dynamic, collapsible menu
Almost every Front-End Developer has run his/her head against the wall when making a nav, and there isn't enough space to fit all menu items.
This little piece of markup and JS is one of many solutions that can be applied. When there isn't enough space, the menu items not fitting the viewport will collapse into a dropdown and "hides". However, this is just a nav-pills-example; a real navbar-example is coming soon.
Try it yourself. Resize the viewport and watch it at work.