*{
    margin: auto;
    padding: 0%;
    font-family: Verdana, Geneva, Tahoma, sans-serif;
    box-sizing: border-box;
}

.container{
    width: 100%;
    height: 100vh;
    background: skyblue;
    display: flex;
    align-items: center;
    justify-content: center;
}

.calculator{
    background: black;
    padding: 40px;
    border-radius: 15px;
    box-shadow: 0px 3px 15px grey;
}

.calculator form input{
    border: 20;
    outline: auto;
    width: 60px;
    height: 50px;
    border-radius: 10px;
    box-shadow: inset;
    background: antiquewhite;
    color: blueviolet;
    font-size: 18px;
    font-weight: 500;
    cursor: pointer;
    margin: 10px;
}

form .display{
    display: flex;
    justify-content: center;
    margin-top: 25px;
    margin-bottom: 15px;
}

form .display input{
    padding-block: 13%;
    text-align: right;
    flex: 1;
    font-size: 40px;
}

form input.operator{
    color: red;
}