Simplify the following text for a Grade 9 native English-speaking person.
Original: As a Southern Gothic novel and a Bildungsroman , the primary themes of To Kill a Mockingbird involve racial injustice and the destruction of innocence .
Simplified: To Kill a Mockingbird is a Southern Gothic novel and a bildungsroman ( a story where the main character develops and grows ) . Its main themes are racism and innocence .