Here's the breakdown:
* Subordinating conjunction: "Even though" connects the dependent clause to the independent clause. It establishes a relationship of concession, meaning the information in the dependent clause contrasts with the information in the independent clause.
* Adverbial clause: "Even though Darla recommended the course" is a dependent clause that modifies the verb "decided" in the main clause. It tells us the circumstance surrounding the decision not to take the course.
* Independent clause: "You decided not to take it" is the main clause, and it expresses the complete thought.
Therefore, the entire sentence is a complex sentence, consisting of a dependent adverbial clause introduced by a subordinating conjunction and an independent clause.