* { margin: 0; padding: 0; box-sizing: border-box; } .container { width: 100px; height: 100px; background-color: #a8b8d8; } .container:hover { background-color: #ffa000; } .container > span { display: inline-block; padding: 10px; background-color: #000; color: #fff; font-family: Arial, sans-serif; border-radius: 0 0 5px 5px; } .container > span::before { content: ""; position: absolute; top: -20px; left: 0; width: 100%; height: 20px; background-color: #000; border-radius: 5px 5px 0 0; }

function add(a, b) {
  return a + b;
}