It seems there is no any problems with css you have written. There may be another side which is effecting the changes. So we request you to provide your site URL, so we can provide your exact and appropriate solution.
You are keeping same value of padding as before.As I told 1rem == 16px. You are keeping 16px for the top value. Try keeping this code:
#content {
padding: 0 0 1rem !important;
}