* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-size: 14px;
}
.index {
  position: relative;
  background-color: #030014;
}
.index .top {
  position: fixed;
  top: 0;
  left: 0;
}
.index .bottom {
  position: fixed;
  bottom: 0;
  left: 0;
}
.index .btn {
  width: 44vw;
  height: 14vw;
  position: absolute;
  top: 104vw;
  left: 50%;
  transform: translateX(-50%);
}