body {
  background-color: #111;
  font-family: "Signika Negative", sans-serif, Arial;
}

#viewport {
  overflow: hidden;
  position: fixed;
  height: 100%;
  width: 100%;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
}

#content {
  overflow: visible;
  width: 100%;
  /* set a height because the contents are position: absolute, thus natively there's no height */
  height: 2400px;
  
  background-image:
    linear-gradient(rgba(255,255,255,.07) 2px, transparent 2px),
    linear-gradient(90deg, rgba(255,255,255,.07) 2px, transparent 2px),
    linear-gradient(rgba(255,255,255,.06) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.06) 1px, transparent 1px);
  background-size: 100px 100px, 100px 100px, 20px 20px, 20px 20px;
  background-position: -2px -2px, -2px -2px, -1px -1px, -1px -1px;
}

.box {
  width: 100px;
  height: 100px;
  background-color: #28a92b;
  position: absolute;
  left: 300px;
  z-index: 100;
  line-height: 100px;
  font-size: 50px;
  text-align: center;
}
.box.active {
  background-color: red;
}

.box-a {
  top: 200px;
  background-color: #8d3dae;
}

.box-b {
  top: 600px;
}

.box-c {
  top: 1000px;
  background-color: #e26c16;
}

.line {
  visibility: hidden;
  width: 2px;
  height: 3000px;
  position: absolute;
  left: 400px;
  top: 0px;
  background-color: #777;
}

header .name {
  color: white;
}

.title {
  position: absolute;
  width: 100%;
  text-align: center;
  color: white;
  font-weight: 400;
  font-size: 40px;
}
header {
  position: fixed;
  right: 0px;
  bottom: 0px;
  padding: 6px 10px 10px 12px;
  border-top-left-radius: 26px;
  z-index: 100;
  background-color: rgba(0,0,0,0.5);
}