html, body {
    width: 100%;
    height: 100%;
    overflow: hidden;
}

body {
    background-color: #ffffff;
    margin: 0;
}

input[type="radio"] {
    margin: 0;
    padding: 0;
    display: block;
    overflow: hidden;
    float: left;
}

#checkbox_holder {
    position: absolute;
    margin: auto;
    top: 0;
    bottom: 0;
    left: 0;
    right: 0;
}

.hidden {
    display: none;
}