Happy and without worry (Cambridge)
(disapproving) showing you do not care or are not anxious about what you are doing (Oxford)
She shows a blithe disregard for danger.(Cambridge)
He drove with blithe disregard for the rules of the road. (Oxford)
shows a blithe disregard for danger
drove with blithe disregard
Carefree
Cheerful
Troubled
Unhappy
Blithely