body{margin:0;padding:0;display:flex;align-items:center;justify-content:center;height:100vh;flex-direction:column;background-color:#000000b5}.app{display:flex;flex-wrap:wrap;align-items:center;justify-content:center;width:278px;height:335px;background-color:#804900}#display{width:270px;height:50px;background-color:#d7a35f;text-align:center;color:#0f0f0c;font-size:30px}button{height:85px;width:85px;margin:3px;font-size:30PX;border-radius:15px}