"Casual" sounds good and has a good meaning.
"Peace of mind" means that our hearts should have peace of mind in life, and we can't have different ideas of love and hate, just like Guanyin Bodhisattva called viewing freedom. Being at ease with others means that the heart is at ease with others; Seeing things at ease, I see everything at ease; I am very comfortable with the scenery, and I am very comfortable with all the scenery. Therefore, our hearts can live in peace.