Edit in JSFiddle

<script src="https://cdn.furkot.com/scripts/furkot-trip-planner.min.js" defer></script>

<span>Plan with Furkot button is a static anchor element &lt;a&gt;&nbsp;. Trip planner is displayed as modal dialog.</span>
<br><br>
<a class="button" href="https://trips.furkot.com/trip?stop[name]=Okemo%20Mountain&stop[address]=77%20Okemo%20Ridge%20Road%2C%20Ludlow%2C%20VT%2005149&stop[coordinates][lat]=43.4046&stop[coordinates][lon]=-72.7442&stop[notes]=Family%20Ski%20and%20Snowboard%20Resort%20in%20Ludlow%2C%20VT&stop[url]=http%3A%2F%2Fwww.okemo.com&stop[pin]=14" target="furkot">Visit Okemo Resort on your trip</a>

.button, .furkot-widget-done::before {
    display: inline-block;
    color: white;
    background: black;
    cursor: pointer;
    padding: .5em;
    border: none;
    font-size: 16px;
    text-decoration: none;
}
.furkot-widget-done {
    visibility: hidden;
    cursor: pointer;
}
.furkot-widget-done.furkot-widget-active::before {
    content: 'x';
    position: absolute;
    left: 50%;
    margin-left: 136px;
    top: 50%;
    margin-top: -216px;
    visibility: visible;
    border: white solid 1px;
    -moz-border-radius: 15px;
    border-radius: 16px;
    height: 8px;
    line-height: 6px;
}
.furkot-widget.furkot-widget-active {
    position: fixed;
    top: 0;
    left: 0;
    opacity: 1;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.75);
    -webkit-transition: opacity 300ms;
    transition: opacity 300ms;
    z-index: 500;
}
.furkot-widget-inactive iframe {
    width: 0;
    height: 0;
}
.furkot-widget-active iframe {
    position: absolute;
    width: 300px;
    left: 50%;
    margin-left: -150px;
    height: 400px;
    top: 50%;
    margin-top: -200px;
}