title: How to select via regex all class notations in css file
body: <p>By having a css file with css rules, I'd like to select only css class (i.e.) <code>.tblGenFixed</code>  but not css values for a rule (i.e.) <code>opacity: 0.3</code> .</p>
  
  <p>This is my regex:
  <code>/(\.([\w_]+))/g</code></p>
  
  <p>This is my alternative solution but it doesn't work
  <code>/(?!\{)(\.([\w_]+))(?!\})/g</code></p>
  
  <p>I have set an example in regex101 here <a href="https://regex101.com/r/gG4nN4/1" rel="nofollow">https://regex101.com/r/gG4nN4/1</a></p>
  
  <p>How can I ignore css rule values ?</p>