body{
    width: 50%;
    margin: auto;
    font-family: Sans-Serif;
    background-color: #caf0f8;
}

h1{
    text-align: center;
    font-size: 2.2rem;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
}

#display{
    background-color: lightgray;
    border: solid;
    height: 48px;
    width: 90%;
    font-size: 40px;
}

button{
    width: 30%;
    height: 56px;
    font-size: 28px;
    margin: 0px;
    float: left;
}

@media only screen and (max-width: 600px) {
    body{
        width: 80%;
    }
}