This box has an outline around it that extends further than the border and goes into the adjacent div.
This box has an outline and is between two boxes that have an outline so the other outlines go into this box and obscure some of the text.
This is the third box that has an outline. The left side of this box is obscured by the outline of the middle box.
This box and the two to the right of it use borders instead of outlines and there isn't any overlap into the other boxes.
Borders and outlines work differently, borders are the border of the box and they directly surround the content.
Outlines are outside of the borders and the encompass all other elements in a div, including the content.