Why is السَّمَاوَاتِ mansub in خَلَقَ اللَّهُ السَّمَاوَاتِ although it ends with kasrah?

Maf'ul Bihi: The Receiver of the Action

• It is a sound feminine plural whose sign of nasb is kasrah.
• It is majrur by an omitted preposition.
• It is the fa'il of the sentence.
• Every word ending in kasrah is mansub.