title: How to create a vignette with background gradients
body: <p><img src="https://i.stack.imgur.com/p9mUO.jpg" alt="enter image description here"></p>
  
  <p>Is there a way to create a background without the use of any actual image files that has a gradient that looks like this?</p>
  
  <p>Not the wood panel texture, but how the left and right are darker and then get lighter as they go inwards.</p>