I must had been out of touch with CSS for a long time.
I had a problem to solve, which requires the reordering of HTML elements using CSS. I was pretty dumb struck because from my experience, you shouldn't be able to do that unless you're modifying the DOM.
Well, turns out that there's a new layout mode Flexbox that does that.
So I started to watch this youtube video Intro and Flexbox Basics — Learn CSS3 Flexbox and it totally blow me away.
I suppose it's time to review the layout model, which I learnt way back when IE6 was a still a pain, that needed all sorts of hacks. #Learn CSS Layout