Есть вот такая штука ещё и аналогичная про флексбокс, сам постоянно пользуюсь

@nikitonsky
~~habroeffected~~

@nikitonsky The `.poster` elements should always have a `span` that will cover more lines that you think it should: in this case the second and third poster should have a span 3 and 4.

If you're ok with removing the vertical gap from the grid, then you could do something like span 99, but with a vertical gap (like in your example) it won't work.