乐不在外表而在心，心以为乐，则是境皆乐，心以为苦，则无境不苦。”帮我翻译一下

Happiness is not an external expression but rather an inner joy. When your heart deems it blissful, everything around you is cheerful. When your heart regards it miserable, nothing is pleasant any more.

古文毕竟很简洁精美，如果可以意译，我主张尽量在形式上也能表现出古风古韵：

Such an inner joy as one's happiness
Rather than a superficial practice
If your heart believes it joyful
All blissful is in the whole world
Yet when your heart deems it painful
Only the woe in the air swirled