Making scrolling elements focusable helps users navigating the site by keyboard scroll those elements. For that reason, it is important these elements are focusable for accessibility reasons. To make an element scrollable, add a tabindex attribute. Set the value of this element to a non-negative value. Negative tabindex values are only used when the element should not be focusable. For positive tabindex values, the order of the values sets the sequence in which users will tab through the elements. That said, you should arrange elements in a logical order and set tabindex to 0 for all focusable element whenever possible.