Tab order
The sequence in which interactive elements receive keyboard focus when the user presses Tab. By default, follows DOM order; elements with positive tabindex jump ahead, which is rarely what authors intend.
Sensible tab order matches reading order. Each interactive element
— button, link, input, custom element with tabindex="0" — joins
the order. Skip links, single-page-app route changes, and modal
dialogs need explicit focus management to keep the order coherent.
A tabindex greater than zero forces an element ahead of others
and almost always confuses users; restrict positive tabindex to
exceptional cases.