Very nice. For those of us who'd appreciate a live demo (like me), I wrote this script:

  document.querySelectorAll('link[rel="stylesheet"], style').forEach((style) => style.remove());
  
  const style = document.createElement("style");
  style.appendChild(document.createTextNode("body{font-family:sans-serif;line-height:140%;max-width:38rem;padding:2rem;margin:auto}h1,h2,h3,h4,h5{margin-bottom:.6rem;line-height:120%}p{margin:0 0 1rem}"));
  
  document.head.appendChild(style);

Hi! Geffrey from … geffrey.io here. Thanks for posting!

That website is a bit wonky, sorry for that.

Thanks again!