Can I DevTools?
  1. Open Command Menu (Cmd+Shift+P or Ctrl+Shift+P) > Run > Show Layers. This will open a new tab called Layers.
  2. For developers, it is useful to visualise a web page in three dimensions to,
    • Find out how complex a web page is
    • Spot out-of-viewport elements
    • Debug z-index stacking issues
    • Debug performance issues with composite layers