I would try to make your design as hack-free as possible, as suggested
already by many.
Since (most) browsers are developing all the time, you run the risk that
a hack maybe solved in a future version of a browser. Using a hack to
abuse the behaviour of a browser is almost-guaranteed a temporary
solution, because behaviour that causes the need for a hack is nothing
more than a bug, and bugs are solved.
To prevent you from having to redo your design, because a hack was up or
outdated, it's in my opinion best not to use any.
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