*{
    box-sizing: border-box;
    font-family: 'Franklin Gothic Medium', 'Arial Narrow', Arial, sans-serif;
    font-weight: bold;
}
body{
    padding:0;
    margin:0;
    background: linear-gradient(to right,#00AAFF,#00FF6C);
}
.calculator{
    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);

}
.calculator > button{
    cursor:pointer;
    font-size: 2rem;
    border:1px solid white;
    outline:none;
    background-color: rgba(255,255,255, 0.75);
}
.span-two{
    grid-column: span 2 ;
}
.output-screen{
    grid-column: 1 /span 4;
    background-color: rgba(0,0,0, 0.75);
    display: flex;
    align-items: flex-end;
    justify-content: space-around;
    color:seashell;
    flex-direction: column;
    padding:10px;
    word-wrap: break-word;
    word-break: break-all;

}
.previous-operand{
    font-size: 1.5rem;
    color:rgba(255,255,255, 0.75);
}
.current-operand{
    font-size: 2.5rem;
    color:white;
}