Amiga Scanline Vibes (Youtube, Twitch, etc.)

scanline.js

// Paste in browser console
(() => { 
  let old = document.getElementById('scanline-overlay'); 
  if (old) old.remove(); 
  document.body.appendChild(Object.assign(document.createElement('div'), {
    id: 'scanline-overlay',
    style: 'position:fixed;top:0;left:0;width:100vw;height:100vh;pointer-events:none;z-index:999999;background-image:repeating-linear-gradient(to bottom, rgba(0,0,0,0.3) 0px, rgba(0,0,0,0.3) 2px, transparent 2px, transparent 4px);'
  })); 
})();