How did the culture of Byzantium differ from the culture of European countries in the Middle Ages?

Speaking about the Middle Ages, we often say that this period in history is usually called the Dark Ages. This is due to the fact that European culture was in decline. European countries were greatly influenced by the Catholic Church and barbaric society and laws. At the same time, the Byzantine state was able to preserve the ancient culture of both Greece and Rome. Architecture, painting and icon painting flourished here. The Cyrillic alphabet appears and develops. Thus, despite the fact that in Byzantium, as well as in the rest of Europe, religion had a great influence on culture and life, the country was able to preserve and develop ancient culture and laws.