.main {
  margin-top: -100px;
}

.header-image {
  position: relative;
  margin-left: -15px;
  margin-right: -15px;
}

.header-image img {
  width: 100%;
}

.header-image .mask {
  position: absolute;
  bottom: -1px;
  height: 50%;
  width: 100%;
}