Ah, I guess I misread "adding elements" to mean "adding attributes". I tab to add a new attribute/value pair within an existing element. I never noticed those right-click options before. The "Add Rule..." makes sense to me: it creates a new rule for 'body' with blank braces, where I can change 'body' to any element name, and insert whatever rules I want.
However, I don't understand the right-click "Add Element Style..." option. It creates this:
element.style {
;
}
What's that for? I can put rules into the braces, but it won't let me change the words "element" or "style". What's up with that? What good is a rule attached to (literally) "element.style"?