Why does Viola help Duke Orsino try to win Olivia when Viola is in love with him herself?

Viola helps Duke Orsino win Olivia because she is disguised as a man, Cesario, and believes that her role as Orsino's messenger allows her to navigate the complexities of love without revealing her own feelings. Additionally, she seeks to keep her true identity hidden while ensuring Orsino's happiness, showing her loyalty and selflessness. Viola's actions reflect the themes of unrequited love and the complications of identity, as she balances her own emotions with her duty to Orsino.