visibility: hidden versus display: none.
What are the differences and when would you use one over the other?
visibility: hidden means that the element is still there and taking up
space on the screen but just can't be seen. (the space taken up by the
content is just a white box).
display: none means that the content is taken out of the flow of the page
altogether. (it may as well not be there in the first place). So this space release.