left-right movement.. css only very generic

Question

I would like to write a generic css animation to move a div right and left, touching the edges of the container .. to be applied in a simple way to any div of which I know n

Answer 1

Use transform combined with left or right to avoid adding any fixed value:

@keyframes destraSinistra {
  0% {
    left: 0;
  }
  100% {
    left: 100%;
    transform:translateX(-100%);
  }
}


#div1 {
  position: absolute;
  border: solid 1px lightgray;
  width: 100px;
  height: 30px;
  background-color: lightgreen;
  animation: destraSinistra 1s linear infinite alternate
}

<div id="div1"></div>