vuepress-theme-plume/docs/en/guide/repl/demo/normal.html

<div id="app">
  <h3>vuepress-theme-plume</h3>
</div>

<script lang="ts">
const a = 'So Awesome!'
const app = document.querySelector('#app')
app.appendChild(document.createElement('small')).textContent = a
</script>

<style lang="css">
#app {
  font-size: 2em;
  text-align: center;
}
</style>