   }

      .box::after {
        content: "This is a string. It is quoted in the CSS.";
      }
    </style>
  </head>

  <body>
    <section class="preview">
      <div class="box"></div>
    </section>

    <textarea class="playable playable-css" style="height: 240px">
.box {
  width:400px;
  padding: 1em;
  border-radius: .5em;
  border: 5px solid rebeccapurple;
  background-color: lightblue;
}

.box::after {
  content: "This is a string. I know because it is quoted in the CSS."
}</textarea
    >

    <