Blend a full background over sliding curtain

HTML & CSS
95

Are you able to see the gap here?

In this code?

I added the red one here and I still don’t see a gap.

https://jsfiddle.net/6mdjb0en/

.slide-wrap:before,
.slide-wrap:after {
  content: "";
  position: absolute;
  top: 0;
  width: 50%;
  height: 100%;
  transition: transform 5s linear;
  background: url(https://picsum.photos/id/1015/1500/1500) no-repeat;
  background-attachment: fixed;
  background-size: cover;
}

698×535 401 KB

If I change the width to 1px;, there is still no gap.
https://jsfiddle.net/92pg0d1t/2/

.slide-wrap:before,
.slide-wrap:after {
  content: "";
  position: absolute;
  top: 0;
  width: 1px;
  height: 100%;
  transition: transform 5s linear;
  background: url(https://picsum.photos/id/1015/1500/1500) no-repeat;
  background-attachment: fixed;
  background-size: cover;
}

656×567 382 KB