① outside ak-cq

Scroll this frame. Badge ① is ak-fixed with no ak-cq ancestor and stays on the frame's viewport. Watch where ② and ③ go.

ak-cq ② ak-fixed in ak-cq

If ② sits in this box's corner and scrolls with it, the containment caveat applies in this browser. If ② stays at the top of the frame, it does not.

contain: layout (control) ③ in contain: layout

Layout containment always captures fixed descendants, so ③ always sits in this box.