body{
    background-color: black;
    color: white;
}
        .display {
            font-size: 50px;
        font-weight: bold;
        margin-bottom: 10px;
        margin-left: 10px;
        }
        .num-btn {
          border: none;
          
          height: 65px;
          width: 65px;
          margin: 5px;
          border-radius: 50%;
          font-weight: bold;
          background-color: rgb(51, 51, 51);
          color: white;
          font-size: 23px;
          cursor: pointer;
        }
        .calc-btn {
            background-color: #fea00a;
        }