CSSによる階層を視覚化（ハイライト）

javascript:(function(){var style=document.createElement('style');var head=document.getElementsByTagName('head');style.setAttribute('type', 'text\/css');style.innerHTML='* {background-color: rgba(255,0,0,.2)!important;}* * {background-color%EF%BC%9Argba(0,255,0%E3%80%81.2)!important;} * * * {background-color%EF%BC%9Argba(0,0,255%E3%80%81.2)!important;} * * * * {background-color%EF%BC%9Argba(255,0,255%E3%80%81.2)!important;} * * * * * {background-color%EF%BC%9Argba(0,255,255%E3%80%81.2)!important;} * * * * * * {background-color%EF%BC%9Argba(255,255,0%E3%80%81.2)!important;} * * * * * * * {background-color%EF%BC%9Argba(255,0,0%E3%80%81.2)!important; } * * * * * * * * {background-color%EF%BC%9Argba(0,255,0%E3%80%81.2)!important;} * * * * * * * * * {background-color%EF%BC%9Argba(0,0,255%E3%80%81.2)!important;}';head[0].appendChild(style);})();

[CSSで実装したレイアウトの構造や階層を簡単に確認できる、私のお気に入りのCSSハック -My favorite CSS hack

コリス](https://coliss.com/articles/build-websites/operation/css/my-favorite-css-hack-by-gajus.html)