HTMLify

*{
    font-family: Arial, Helvetica, sans-serif;
    background-color:#fff;
    margin: 0;
    padding: 0;
    width: 80%;
    align-items: center;
    box-sizing: border-box;
    justify-content: center;
    max-width: 100%;
}
body{
    justify-content: center;
    align-items: center;
}
.Calculator{
    width: 70%;
    max-width: 200PX;
    margin: 0 auto;
    text-align: center;
    background-color: #f8F8;
    padding: 50px 0;
    border-radius: 10px;
    justify-content: center;
}
.red{
    background-color: red;
}
.blue{
    color: blue;
}
.green{
    color: green;
}
input[type="text"]{
    width: 100%;
    height: 50px;
    margin-bottom: 10px;
    font-size: 40px;
    border-radius: 5px;
    text-align:right;
    box-shadow: #f8f8;
}
button{
    width:40px ;
    height: 40px ;
    font-size: 24px;
    padding: 5px;
    cursor: pointer;
    border-radius: 10px;
    margin-bottom: 3px;
    background-color: #bdbdbd;
}
button:hover{
    background-color: #ddd;
}
button:active{
    transform: scale(0.95);
}