ments.html",
    "performance.html",
    "future_work.html",
    "related_work.html",
    "thanks_utilities.html",
    "live_demo.html",
];

var previous = d3.select("#previous"),
    current = d3.select("#current"),
    next = d3.select("#next"),
    query = "?" + Date.now(),
    previousIndex,
    currentIndex = +location.hash.substring(1) || 0,
    nextIndex;

resize();
step(0);

d3.selectAll("iframe").on("load", function() {
  this.contentWindow.focus();
  d3.select(this.contentWindow).on("mousewheel", 