* {
    margin: 0;
    box-sizing: border-box;
    background-color: #f4f4f4;
}

#demo {
    font-family: Arial, "Helvetica Neue", Helvetica, sans-serif;
    font-size: calc(3px + 1.5vw);
    padding: 3vw;
    margin-top: 1%;
    color: #333;
}

#page-wrapper {
    width: 90%;
    margin: auto;
    padding: 2vw;
    text-align: center;
    background-color: white;
}

header {
    padding: 2vw;
    color: #333333;
}