style.css

body {
  margin: 0;
  padding: 0;
  font-family: 'Helvetica Neue', 'Arial', 'sans-serif';
  line-height: 25px;
}
#map { position:absolute; top:0; bottom:0; width:100%; background-color: #202222; }
#map1 { position:absolute; top:0; bottom:0; left:0; right:50%; background-color: #202222; }
#map2 { position:absolute; top:0; bottom:0; left:50%; right:0; background-color: #202222; }
#toggle {
  position: absolute;
  background-image: url('swipe.png');
  background-color: rgba(255, 255, 255, 0.5);
  z-index: 20000;
  top: 10px;
  right: 10px;
  width: 52px;
  height: 26px;
  cursor: pointer;
  border-radius: 3px;
}
#range {
  top: 50%;
  width: 100%;
  position: absolute;
}
input[type=range] {
  -webkit-appearance: none;
}
input[type=range]:focus {
  outline: none; 
}
input[type=range]::-webkit-slider-thumb {
  -webkit-appearance: none;
  border: 1px solid rgba(255, 255, 255, 0.5);
  height: 60px;
  width: 60px;
  border-radius: 30px;
  background: rgba(255, 255, 255, 0.5);
  cursor: pointer;
  margin-top: -14px;
  box-shadow: 1px 1px 1px #000000, 0px 0px 1px #0d0d0d;
}
input[type=range]::-webkit-slider-runnable-track {
  width: 100%;
  height: 0;
}
h2 {
  font-size: 35px;
  padding: 0 0 30px 0;
  border-bottom: 1px solid #999;
  margin-left: -100px;
  padding-left: 100px;
  margin-right: -100px;
  padding-right: 100px;
  box-shadow: 0px 3px 3px #f5f5f5;
}
h3 {
  font-size: 25px;
}
a {
  text-decoration: none;
  color: #084e9d;
}
.bold {
  font-weight: bold;
}
.leaflet-bar, .leaflet-control-layers, .leaflet-bar a:hover {
  background-color: rgba(255, 255, 255, 0.5);
}

#help {
  margin: 100px;
  display: none;
}
dd {
  margin: 0;
  padding: 0 0 20px 0;
}

.button {
  border-radius: 5px;
  background: #084e9d;
  padding: 5px 15px;
}
  .button:hover {
    background: #0a66ce;
  }
a.button {
  color: #fff;
}

#forkme {
  float: right;
}

@media (max-width: 700px) {
  #help {
    margin: 100px 10px 10px 10px;
  }
  h2 {
    margin-left:  -10px;
    padding-left:  10px;
    margin-right: -10px;
    padding-right: 10px;
  }
  #forkme {
    display: none;
  }
}