.machi-arai #content-hdr {
  margin-bottom: 177px;
  background: linear-gradient(to bottom, #fff 319px, #FBDFD7 319px, #FBDFD7 750px, transparent 750px);
}

@media screen and (max-width: 750px) {
  .machi-arai #content-hdr {
    margin-bottom: 89px;
    background: linear-gradient(to bottom, #fff calc((100vw - 40px) * 0.509), #FBDFD7 calc((100vw - 40px) * 0.509));
  }
}