<h1>Clarke’s Three Laws</h1>
<ol>
  <li>When a distinguished but elderly scientist states that something is possible, he is almost certainly right. When he states that something is impossible, he is very probably wrong.
  <li>The only way of discovering the limits of the possible is to venture a little way past them into the impossible.
  <li>Any sufficiently advanced technology is indistinguishable from magic.
</ol>
@import url(https://fonts.googleapis.com/css?family=Merriweather);
* { box-sizing: border-box; }
body { 
  font-family: Merriweather, serif; 
  font-weight: 500; font-style: normal;
  font-size: 1.6rem; margin: 0 auto; 
  max-width: 44rem; } 
h1 { text-align: center; }
ol { 
  line-height: 1.6;
  list-style-type: none;
  counter-reset: section;
  margin-left: 3rem;
}
li {
    counter-increment: section;
    margin-top: 2rem;
}
li:before {
    content: counters(section,"");
    border: 2px solid #000;
    border-radius: 50%;
    display: inline-block;
    float: left;
    width: 3.5rem;
    height: 3rem;
    text-align: center;
    padding-top: .25rem;
    font-weight: 700;
    margin-left: -5rem;
    margin-right: 1rem;
    background: rgba(0,0,0,0.025);
}

@media screen and (max-width: 30em) { 
  ol { margin-left: 0; } 
li:before { 
  display: block;
  float: none;
  margin: 1rem auto;
}

External CSS

This Pen doesn't use any external CSS resources.

External JavaScript

  1. https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.3/jquery.min.js