Navigation sidebar sub-sections are difficult to distinguish
Sub-sections in the left navigation bar are only indented a small amount, and the color is very similar to the parent color (at least in dark mode, I don't see a switch to manually toggle to light mode).
Here we can see the Getting started
section is expanded, but it can be difficult at a glance to tell which parts of the nav area are the children of the expanded area at a glance.
For color contrast, should probably aim for 3:1 ratio. Current is 1.07:1.
Additionally there should be a reliable non-color way to distinguish as well according to the HIG, and the current tiny indentation doesn't seem sufficient.