*, *::before, *::after{
    box-sizing: border-box;
    font-family: "gotham rounded", sans-serif;
    font-weight: normal;
}
 body{
    padding: 0;
    margin:0;
    background-color: rgb(37, 103, 156);
 }

 .calcualtor-grid{
    display:grid;
    justify-content: center;
    align-content:center;
    min-height: 100vh;
    grid-template-columns: repeat(4,100px);
    grid-template-rows: minmax(120px,auto) repeat(5,100px);
 }

 .calcualtor-grid > button{
    cursor:pointer;
    font-size:2rem;
    border: 1px solid  white;
    outline:none;
    background-color: rgba(255, 255, 255, 0.75);
 }

 .calcualtor-grid > button:hover{
    background-color: rgba(255, 255, 255, 0.9);
 }

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

 .output{
    grid-column:1/-1;
    background-color: rgba(0,0,0,.75);
    display:flex;
    align-items: flex-end;
    justify-content: space-around;
    flex-direction: column;
    padding:10px;
    word-wrap: break-word;
    word-break:break-all;
    
 }

 .output #previous-operand{
    color: rgba(255,255,255,0.75);
    font-size:1.5rem;
 }

 .output{
    color: rgba(255,255,255);
    font-size:2.5rem;
 }