Collapsed panels are great for real-estate and for giving the user a simple overview about the topics... however there is a big shortcoming: If you target an id inside a collapsed panel, the browser will just reach the page, and won't be able to show the actual id.

A possible CSS-only solution to solve this problem, and automatically expand the container(s) could be applying this rule the the container root/elements that must expand (so nested panel would also expand):

/* This targets any div that contains the currently active ID in the URL */
div:has(:target) {
  height: auto !important;
  display: block;
}

A similar rule should apply also to unselected tabs, (although you have to hide the current selected one, and I did not reverse-engineered the tabs, so I am not able to suggest anything ATM).

HTH