header {
  padding: 1.5rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  border-bottom: 1px solid #ddd;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background-color: #fff;
  z-index: 999;
}
header > button,
header > a {
  text-indent: -9999px;
  width: 3.5rem;
  height: 3.5rem;
}
header .back {
  background: url("../img/prev.png") no-repeat 0% center / 1.2rem;
}
header .home {
  background: url("../img/home.png") no-repeat 100% center / contain;
}

main {
  margin-top: 6.6rem;
}