title: Make a line with 2 different colors , one in the center and another at the edges
body: <p><a href="https://i.stack.imgur.com/n8uFt.png" rel="nofollow noreferrer">enter image description here</a></p>
  
  <p>I have this kind of a line, I want to make something like this but can't find how to do it . Should I use 2 lines one on another for achieve this effect or can I make it in another way ? I was also looking on <code>linear-gradient</code> , but didn't get the same result . Or it have to be something like different opacity at the edges ?</p>