.base {
  position: relative;
  padding-top: 7%;
}
.base_links {
  position: relative;
  z-index: 1;
  width: 100%;
}
.base_links li {
  margin-bottom: 10%;
}
.base_bg {
  position: absolute;
  top: 0;
  left: 0;
  z-index: 0;
  width: 100%;
}
.base_bg img {
  width: 100%;
}
@media only screen and (max-width: 480px) {
  .base {
    padding-top: 0;
  }
}