Two divs alongside each other: first sticked and the second centered

Question

I want to place two divs alongside each other. Second one to be centered and the first one to be on the left from second and to be sticked / fixed. Because of the last condition

Answer 1

Something like this:

.container {
  display: flex;
  height:100%;
}

.left {
  margin-left: auto;
  width: 0;
  display: flex;
  justify-content: flex-end;
}

.centered {
  margin-right:auto;
  padding:5px;
  background:green;
  height:100%;
}

.left span {
  position:fixed;
  white-space: nowrap;
  padding:5px;
  background:red;
}

body {
 height:200vh;
}

<div class='container'>
  <div class='left'><span> some content</span></div>
  <div class='centered'>centered</div>
</div>