html, body {
  margin:0;
  padding:0;
  overscroll-behavior-y:none;
  position:fixed;
  overflow:hidden;
}
body {
  background-color: #eeeeee;
  font-family:sans-serif;
  font-size:12px;
}

/* Tracks */
canvas {
  background-color:#ffffff;
  cursor:crosshair;
  vertical-align:bottom;
}

div#overlay {
  position:absolute;
  top:0px;
  right:0px;
  bottom:0px;
  left:0px;

}

div#start-btn {
  position:absolute;
  top:50%;
  left:50%;
  transform:translate(-50%, -50%);
  padding:20px 22px 18px 24px;

  font-size:36px;
  color:#000000;
  background-color:#6666ff;

  border-radius:8px;
  cursor:pointer;
}

div#start-btn:hover {
  color:#ffffff;
  background-color:#cc3333;
}