I'm no expert on this, but I personally wouldn't think that there would be much of a difference in setting something to display: "unset" vs display: "block". I might be totally mistaken though, but I think with an effect like this the performance-hit should be pretty much negligable.   Given this was just an idea (and we don't even know if that is what jatinsangwan even wanted to achieve) I didn't put too much thought into it, tbh. But you are right, there is always room to i