Bolt Z-index

Add the utility class xx where xx equals the z index level you wish to apply.

For example: .fab

Z-Index: contentTop: 80
Utility Class: contentTop

Z-Index: content: 60
Utility Class: content

Z-Index: contentBottom: 40
Utility Class: contentBottom

Z-Index: backgroundTop: 20
Utility Class: backgroundTop

Z-Index: background: 0
Utility Class: background

Z-Index: backgroundBottom: -20
Utility Class: backgroundBottom

SassDoc references
Debug Panel