title: Three level decimal ordered list CSS
body: <p>I have a three level ordered list in html that I would like to give a style as following: </p>
  
  <pre><code>1. Item 1
  1.1 Item 2
  1.1.1 Item 3
  </code></pre>
  
  <p>An example of the html is in the next plunker:</p>
  
  <p><a href="http://plnkr.co/edit/DqhZ5pJILTUHGSNaA1vm?p=preview" rel="nofollow">http://plnkr.co/edit/DqhZ5pJILTUHGSNaA1vm?p=preview</a></p>
  
  <p>I have done a style recommended in the internet with css like </p>
  
  <pre><code>ol { counter-reset: item }
  li:before { content: counters(item, "."); counter-increment: item } 
  </code></pre>
  
  <p>but it doesn't seem working.</p>
  
  <p>Please, any comment related would be a great help.</p>