css-layout-hack.js

// create a bookmark and use this code as the URL, you can now toggle the css on/off
// thanks+credit: https://dev.to/gajus/my-favorite-css-hack-32g3
(function() {
  const element = document.querySelector('#test-layout-styles');
  if (element) {
    document.head.removeChild(element);
  } else {
    const style = document.createElement('style');
    style.id = 'test-layout-styles';
    style.innerHTML = `
        * { background-color: rgba(255,0,0,.2); }
        * * { background-color: rgba(255,0,255,.2); }
        * * * { background-color: rgba(0,255,255,.2); }
        * * * * { background-color: rgba(255,255,0,.2); }
        * * * * * { background-color: rgba(0,255,0,.2); }
        * * * * * * { background-color: rgba(0,0,255,.2); }
        * * * * * * * { background-color: rgba(255,0,0,.2); }
        * * * * * * * * { background-color: rgba(255,255,0,.2); }
        * * * * * * * * * { background-color: rgba(0,255,255,.2); }
    `;
    document.head.appendChild(style);
  }
})();