localhost:3000でFlutterみたいなデバッグラベルを表示するやつ by Comamoca

/* ==UserStyle==
@name           localhost
@namespace      github.com/openstyles/stylus
@version        1.0.0
@description    A new userstyle
@author         Me
==/UserStyle== */

@-moz-document url-prefix("http://localhost:3000/") {
    body::before {
      content: "DEBUG";
      position: absolute;
      display: block;
      width: 210px;
      padding: 10px 0;
      background: red;
      color: white;
      font: bold 16px sans-serif;
      text-align: center;
      transform: rotate(-45deg);
      transform-origin: 0 0;
      top: 100px;
      left: -50px;
      box-shadow: 0 0 10px rgba(0,0,0,0.3);
    }
}