.left__margin,
.right__margin {
  opacity: 25%;
}
.left__margin {
  z-index: 1;
  position: absolute;
  background-color: red;
  width: 300px;
  height: 100%;
}
.right__margin {
  z-index: 1;
  position: absolute;
  background-color: red;
  width: 300px;
  height: 100%;
  right: 0;
}
.right__centerGuide {
  z-index: 1;
  position: absolute;
  background-color: blue;
  width: 653px;
  height: 100%;
  top: 0;
  right: 300px;
  opacity: 25%;
}
.left__centerGuide {
  z-index: 1;
  position: absolute;
  background-color: green;
  width: 653px;
  height: 100%;
  top: 0;
  left: 300px;
  opacity: 25%;
}