After a few years you find out it's not that hard to support it. Prefer padding instead of margins, be careful with floats, use overflow:hidden to clear blocks, add a sprinkle of zoom:1, and it's done. It won't look exactly the same, but don't sweat it - it just needs to work.
But thank god I usually don't need to do any of this anymore :)
But thank god I usually don't need to do any of this anymore :)