.theorem { padding: 1em; margin: 15px 0; color: #323232; border-left: solid 4px #565656; background:#f5f5f5; border-radius: 0 10px 10px 0; } .theorem p { padding: 0; margin: 0; } .proof { padding: 1em; margin: 15px 0; color: #323232; backg…