The basic method for a Sticky Footer Layout is setting min-height:100% on your main containing div after you set height:100% on the body & html elements. That allows the main divs BG color to expand with content.
The footer div then sits outside of the main containing div and is pulled back into the wrapper with a negative top margin or you pull the wrapper through the screen with a negative top margin and leave the footer as is. The footer needs to be a fixed height and the negative top margin (either on the footer or the wrapper) should match the footer’s height. That is what your layout did not take into account.
The range property of the scrollbar is a list of two integers: for example, (0 100). The value of the scrollbar determines the position of the scrollbox along the length of the scrollbar. The value of the scrollbar is an integer within the range.