<div class="slide slide__left"></div>
<div class="slide slide__right"></div>

@import url("https://fonts.googleapis.com/css2?family=Exo:wght@600&display=swap");

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  width: 100vw;
  min-height: 100vh;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: "Exo", Arial, sans-serif;
  font-size: 20px;
  font-weight: 600;
  background: linear-gradient(to bottom, #0b0a27, #31304c 50%);
}

.slide {
  flex: 1;
  height: 100vh;
  background: url("//www.w3cplus.com/sites/default/files/blogs/2020/2009/sf01105963sm.jpg")
    repeat-x;
}

.slide__left {
  background-color: #f09;
  background-position: left top;
  animation: slide_left 5s linear alternate infinite;
}

.slide__right {
  background-color: #09f;
  background-position: right top;
  animation: slide_right 5s linear alternate infinite;
}

@keyframes slide_left {
  from {
    clip-path: inset(0 100% 0 0);
  }
  to {
    clip-path: inset(0 0 0 0);
  }
}

@keyframes slide_right {
  from {
    clip-path: inset(0 0 0 100%);
  }
  to {
    clip-path: inset(0 0 0 0);
  }
}