title: CSS: Border with border-radius has bad quality
body: <p>I want to know how can I fix the border of this play button. It has <code>1px</code> of border and <code>50%</code> border-radius, and it looks ugly. 2px looks ok but I need 1.</p>
  
  <p><a href="https://i.stack.imgur.com/mw6qZ.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/mw6qZ.png" alt="enter image description here"></a></p>