body {
    margin: 0;
    padding: 0;
}

iframe {
    padding: 0px;
    margin: 0px;
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0px;
    left: 0px;
    z-index: 1;
}

.buttons {
    position: absolute;
    color: #000;
    top: 10px;
    left: 15%;
    z-index: 9;
    font-size: 20px;
    cursor: pointer;
}

    .buttons .button {
        float: left;
        display: inline;
        margin-left: 20px;
    }

    .buttons .selected {
        font-weight: bolder;
        text-decoration: underline;
    }