collaspe code

[optiontwo]

What magic words to I need to add to a hiding rule to collapse the space?

[mapx]

it should work automatically, but there are some cases it does not.
example cases ?

[lewisje]

I know that in some cases, like Yahoo! Mail, the reading pane is deliberately styled so that it doesn't fill the viewport, so if you block the ad to the right and hide the space where it would go, there's just blank space; generally, you need a UserStyle or a UserScript to fix this, and adding such functionality to ABP is out of scope.