css - Weird behavior in Firefox with outlines and pseudo-elements

Question

Firefox behaves differently than Chrome and Safari (I haven't tested others browsers) when you combine outline and pseudo-elements. Is there a way to fix it or is this a bug?

.main {
  position: relative;
  width: 100px;
  height: 100px;
  margin: 10px auto;
  border: 2px solid #f00;
  outline: 2px solid #00f;
}
.main:after {
  content: 'Hello';
  position: absolute;
  width: 100px;
  text-align: center;
  bottom: -50px;
}
.wtf {
  width: 400px;
  margin: 90px auto;
}

<div class="main"></div>
<div class="wtf">
  <p>In Chrome and Safari the 'Hello' is outside of the outline.</p>
  <p>In firefox the outline is extended and the 'Hello' is inside the outline. Bug from Firefox or is there a way to fix this?</p>
</div>

Answer 1

Now used to

box shadow

as like this

.main {
  position: relative;
  width: 100px;
  z-index:1;
  height: 100px;
  margin: 10px auto;
  border: 2px solid #f00;
  box-shadow:0px 0px 0px 3px #00f;
}
.main:after {
  content: 'Hello';
  position: absolute;
  text-align: center;
  bottom: -50px;
  left:0;
  right:0;
  z-index:2;
}

.wtf {
  width: 400px;
  margin: 90px auto;
}

Demo