There is no easy way to get to the top level menus, like Concepts, Setup, Tasks, etc. If someone wants to read the description for the individual entries, they have to do a few extra steps to figure it out.

Example:

• go to https://preliminary.istio.io
• select Docs

You can see the top level menus on the left, but clicking on them only expands/contracts them.

To actually get to one, you need to click on it to expand it, then click on one of the sub links, and then click back one path entry on the crumb trail across the top.

Example:

• Click Concepts to expand
• Click What is Istio
• Click Concepts in the bread rumbas across the top.

Not sure if this is Working as Designed or not. Just pointing out a potential drawback.