<!DOCTYPE html>
<style>
.anchor {
  width: 100px;
  height: 100px;
  background: orange;
}

.target {
  position: fixed;
  background: lime;
  width: 100px;
  height: 100px;
}

body {
  margin: 0;
}

#anchor1 {
  margin-left: 100px;
}

#target1 {
  left: 100px;
  top: 100px;
}

#anchor2 {
  margin-left: 300px;
  margin-top: 100px;
}

#target2 {
  left: 300px;
  top: 300px;
}
</style>

<div id="anchor1" class="anchor">anchor1</div>
<div id="anchor2" class="anchor">anchor2</div>

<div id="target1" class="target">target1</div>
<div id="target2" class="target">target2</div>
