Hi, can you be more specific about what it is you are trying to accomplish?
Also, are you trying to make the entire post invisible or to make it disappear altogether? I know it sounds like the same thing, but in CSS these are two different things:
visibility:hidden renders the target invisible but still occupying the space it would otherwise occupy in the viewport if it were visible;
display:none makes the entire element disappear from the viewport, so any elements that come after it would occupy the space the disappeared element would have.
For more detail about this, see w3schools: