I don't think writing a custom grid system is reinventing the wheel, since it's a task too small to even employ such consideration. It's like saying creating a

I don't think writing a custom grid system is reinventing the wheel, since it's a task too small to even employ such consideration. It's like saying creating a folder structure for your project is reinventing the wheel. Anyway, there's a rather diffuse line between reinventing the wheel and optimizing/fitting your own particular needs. I can easily agree that I've ended up - many times - in the first region while trying to reach the latter. Still, I'd say "no harm" if a) you got a cleaner, more legible source code; b) you got a better grasp of your solution; c) you're learning; and d) saving a few milliseconds from each of your users.