h2{margin:0 0 1rem}body{-webkit-transition:background-color 5s ease;-moz-transition:background-color 5s ease;transition:background-color 5s ease}body.def{background-color:#def}body.dfe{background-color:#dfe}body.edf{background-color:#edf}body.efd{background-color:#efd}body.fde{background-color:#fde}body.fed{background-color:#fed}