.aa1 { background-color: lightblue; color: cursor: pointer; padding: 5px; height: 18; width: 100%; border: 10px; text-align: left; outline: 5px solid white; font-size: 16px; transition: 0.4s; } .aa { background-color: #0ff; cursor: pointer; padding: 5px; height: 20; width: 100%; border: 10px; text-align: left; outline: 5px solid white; font-size: 14px; transition: 0.4s; } pp:active { background-color: #ccc; } aa:active { background-color: #fff; } .aa:hover { background-color: #ccc; } .pp { padding: 3px 0px; display: none; background-color: white; overflow: hidden; } Course Exercises Exercises may be selected from the drop-down menus above.