html, body {
  overflow: hidden;
  margin: 0;
  background-color: #333;
}
body {
  font-family: 'Open Sans', 'Helvetica Neue', 'Hiragino Sans GB', 'LiHei Pro', Arial, sans-serif;
  color: #333;
}
#particles {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}
#app {
  position: absolute;
  width: 320px;
  text-align: center;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  user-select: none;
}
h2 {
  color: #999;
  font-weight: normal;
  font-size: 15px;
  letter-spacing: .12em;
  margin-bottom: 30px;
}
p {
  color: #999;
  font-size: 14px;
  line-height: 2em;
  margin: 0;
  letter-spacing: 2px;
}
a {
  color: #999;
  text-decoration: none;
  transition: color .2s ease;
}
a:hover {
  color: #0176BA;
}
img {
  width: 100px;
  height: 100px;
}
#extern {
  position: absolute;
  text-align: center;
  bottom: 1%;
  left: 50%;
  transform: translateX(-50%);
  font-family:'Segoe UI', Tahoma, Geneva, Verdana, sans-serif
}
#extern div {
  color: #999;
  font-size: 8px;
  line-height: 0.2em;
  margin: 0;
  letter-spacing: 2px;
}