<!doctype html>
<meta charset="utf-8">
<title>Reference: overflow:clip doesn't affect the box' own outline</title>
<link rel="author" title="Mats Palmgren" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1531609">
<style>
  .outer {
    width: 50px;
    height: 50px;
    margin-left: 100px;
    margin-top: 100px;
    background: black;
    outline: 2px solid grey;
  }

  .inner {
    position: relative;
    background: blue;
    height: 100px;
    width: 100px;
    opacity: 0.5;
  }
</style>
<!-- there should be no overflow -->
<div class="outer">
  <div class="inner" style="width:50px; height:50px;"></div>
</div>

<!-- there should be overflow in the vertical dimension, but not horizontally -->
<div class="outer">
  <div class="inner" style="top:-10px; width:50px"></div>
</div>

<!-- there should be overflow in the horizontal dimension, but not vertically -->
<div class="outer">
  <div class="inner" style="left:-30px; height:50px"></div>
</div>