TopLeaf 8 implements a new style manager for any new publications created using TopLeaf. Some older publications may still access the new style, manager, if their styles were originally created with TopLeaf 7.
In order to access the new style manager for older publications, open a partition in the publication, then run "Commands->Stylesheet Upgrade". The command will only be available if your publication is eligible for upgrading.
Once upgraded, you cannot roll back to the old styles. If you suspect you may wish to roll back at some point, make a backup copy of your publication's existing component stylesheet files (*.def, *.ini,, *.typ, layout.xml), or simply copy the publication hierarchy to a backup location.