body{
    margin:0;
    display:flex;
    justify-content:center;
    align-items:center;
    height:100vh;
    background:#0d0d0d;
    font-family:Arial;
}

.box{
    background:#1b1028;
    padding:20px;
    border-radius:15px;
    box-shadow:0 0 15px #6a0dad;
}

#screen{
    width:100%;
    height:50px;
    margin-bottom:10px;
    font-size:22px;
    text-align:right;
    background:#000;
    color:#fff;
    border:none;
    border-radius:8px;
}

.buttons{
    display:grid;
    grid-template-columns:repeat(4,60px);
    gap:10px;
}

button{
    height:55px;
    border:none;
    border-radius:8px;
    background:#32174d;
    color:white;
    font-size:20px;
    cursor:pointer;
}

button:hover{
    background:#5b2c87;
}