Simplify the following text for a Grade 13 native English-speaking person.
Original: After the Great Destruction of Athens by the Persian Empire in 480 BC , the town and acropolis were rebuilt , and theater became formalized and an even more major part of Athenian culture and civic pride .
Simplified: After the Great Destruction of Athens by the Persian Empire in 480 BC , the town and acropolis were rebuilt , and theater became an even more major part of Athenian culture and civic pride .