body{
    justify-content: center;
    align-items: center;
    user-select: none;
}

.main{
    display: flex;
    justify-content: center;
    align-items: center;
}

form{
    width: 400px;
    height: 500px;
    padding: 25px;
    background-color: black;
    border-radius: 15px 15px 15px 15px;
}

#calculator::placeholder{
    color: rgb(223, 220, 220);
    font-size: 32px;
    text-align: end;
}

#calculator{
    width: 95%;
    height: 100px;
    background-color: whitesmoke;
    font-size: 30px;
    border-radius: 15px 15px 15px 15px;
}

button{
    width: 94px;
    height: 50px;
    cursor: pointer;
    margin-top: 10px;
    font-size: 20px;
    border-radius: 15px 15px 15px 15px;
    border-color: silver;
}


@media only screen and (width < 800px){

    form{
        height: auto;
        text-align: center;
    }
    button{
        width: 80px;
    }
}