CSS question making a video height display right

Hello,

I'm trying to make this vimeo video display no more of a height than 400px but it doesnt do so.

.page-id-1483 .module-slider.slider-overlay li {
  max-height: 400px;
}

just noticed. What if I dont want it tied to a page id? Just remove that part?

is this code wrong?

this is my page http://www.customprowebsites.com/?page_id=2409

Thank you,
Joe