*, *::before ,*::after{
    box-sizing: border-box;
    font-family: 'Courier New', Courier,sans-serif;
    font-weight: normal;
}

body{
    padding: 0;
    margin: 0;
    background: linear-gradient(to right, #000,white);
}


.calculator{
    display: grid;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    grid-template-columns: repeat(4,100px);
    grid-template-rows: minmax(80px, 200px) repeat(5,62px);
}

.calculator > button{
    cursor: pointer;
    font-size: 48px;
    border: 1px solid black;
    outline: auto;
    background-color: lightslategrey;

}

.calculator > button:hover{
    background-color: lightgoldenrodyellow;

}

.span-two{
    grid-column: span 2;
}

.output{
    grid-column:1 / -1;
    background-color: wheat;
    display: flex;
    align-items: flex-end;
    justify-content: space-around;
    flex-direction: column;
   padding: 15px;
    word-wrap: break-word;
    word-break: break-all;
}

.output .previous-operand{
    color: lightgrey;
    font-size: 20px;
}

.output .current-operand{
    color:aliceblue;
    font-size: 45px;
}