Sticky Table header tables don't inherit parent table's outer width

When CSS is used that puts a border around sticky tables, the sticky header table doesn't inherit the full outer width of its parent. As a result, all header columns slightly dip toward center. Also, a slight gap appears on the right between header table and parent table's border, unless table.sticky-header is given a margin-left equivalent to the left border width.

Note that it doesn't matter if table.sticky-header is given the same border--this issue still occurs.