1: Bare (v8 exact)

2: + dt-root only

Root wrapper, no track/group

3: + track (z-index:1)

Root + track with z-index:1

4: + group (container+overflow)

Full structure with labels

5: Full BUT no container-type

Group: container-type:normal, overflow:visible

6: Full BUT track z-index:auto

Track without stacking context