When viewed in landscape, Kagi stretches to the full width of viewport, including behind cutouts like notches or Dynamic Islands.

Site content should not be obscured by physical screen constraints.
This can be solved in CSS, e.g.
.container {
padding-left: env(safe-area-inset-left);
padding-right: env(safe-area-inset-right);
}
This pushes your content away from non-rectangular screen areas like cutouts and rounded corners.