@import url('https://fonts.googleapis.com/css2?family=Poppins&display=swap');
*{  
    margin: 0;
    padding: 0;
    font-family: 'Poppins',sans-serif;
    box-sizing: border-box;
    user-select: none;
}
body{
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: #091921;
}
.calculator{
    position: relative;
    display: grid;
}
.calculator .value{
    grid-column: span 4;
    height: 100px;
    text-align: right;
    border: none;
    outline: none;
    padding: 10px;
    font-size: 18px;
    border-radius: 5px;

}
.calculator span{
    display: grid;
    height: 60px;
    width: 60px;
    color: #fff;
    background: #0c2835;
    align-items: center;
    justify-content: center;
    border: 1px solid rgba(0,0,0,.1);
    border-radius: 5px;
    margin: 5px;
}
.calculator span:active{
    background:#74ff3b;
    color: #111;
}
.calculator span.clear{
    grid-column: span 2;
    width: 120px;
    background: #ff3077;
}
.calculator span.clear:active{
    background:#74ff3b;
    color: #111;
}
.calculator span.plus{
    grid-row: span 2;
    height: 120px;
}
.calculator span.equal{
    background:#03b1ff;
}
.calculator span.equal:active{
    background:#74ff3b;
    color: #111;
}
form{
    border: 2px solid greenyellow;
    padding: 10px;
}