<!DOCTYPE html>
<style>
body { margin: 0; }
.parent {
  position: relative;
  display: flex;
  width: 100%;
  height: 100px;
  background: red;
}

.content {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  margin: auto;
  width: 100px;
  height: 100px;
  background: green;
}

svg {
  width: 50px;
  height: 50px;
}
</style>
<div class="parent">
  <div class="content">
    <svg xmlns="http://www.w3.org/2000/svg"></svg>
  </div>
</div>
