What css selector do I use to style tiddler view controls? Thank you.
.tc-tiddler-controls button will get you all the View Toolbar buttons, including the ones in the “More actions” dropdown. If you don’t want to style those as well, .tc-tiddler-controls > button should give you just the top-level buttons.
Each individual button also has a unique class based on the URI-encoded name of the button tiddler, e.g. tc-btn-%24%3A%2Fcore%2Fui%2FButtons%2Fmore-tiddler-actions. This is derived from {{{ [<listItem>encodeuricomponent[]addprefix[tc-btn-]] }}}, where <<listItem>> is a tiddler like $:/core/ui/Buttons/more-tiddler-actions.