* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html,
body {
    width: 100%;
    height: 100%;
    font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
    font-size: 100%;
    line-height: 1.5;
}


#container {
    position: relative;
    width: 100%;
    height: 100%;
    background: #ffffff;
}

    #container #infobox {
        background-color: #efefef;
        color: #666666;
        padding: 30px 25px;
        width: 100%;
        max-width: 600px;
        min-height: 300px;
        position: absolute;
        transform: translate(-50%, -50%);
        left: 50%;
        top: 35%;
        text-align: center;
    }

#infobox h1 {
    font-size: 2.5em;
    padding: 10px 0 20px 0;
}