.b-lazy {
  background-repeat: no-repeat;
  background-size: cover;
  background-position: center;
}
.banner img {
  width: 100%;
  height: 100%;
}
.w860 {
  width: 860px;
  margin: 0 auto;
}
.part {
  width: 100%;
}
@media (max-width: 860px) {
  .w860 {
    width: 100%;
  }
}
@media (max-width: 750px) {
  .container-fluid {
    padding-top: 1rem;
  }
  .w860 {
    width: 100%;
  }
}