pinafore/routes/_components/DynamicPageBanner.html

<div class="dynamic-page-banner">
  <h1 class="dynamic-page-title">{{title}}</h1>
  <button type="button"
          class="dynamic-page-go-back"
          on:click="onGoBack(event)">Back</button>
</div>
<style>
  .dynamic-page-banner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: 20px 20px 20px;
  }
  h1.dynamic-page-title {
    margin: 0;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  button.dynamic-page-go-back {
    font-size: 1.3em;
    color: var(--anchor-text);
    border: 0;
    padding: 0;
    background: none;
  }
  button.dynamic-page-go-back:hover {
    text-decoration: underline;
  }
  button.dynamic-page-go-back::before {
    content: '<';
    margin-right: 5px;
  }
  @media (max-width: 767px) {
    .dynamic-page-banner {
      margin: 20px 10px 20px;
    }
    h1.dynamic-page-title {
      font-size: 1.3em;
    }
    button.dynamic-page-go-back {
      font-size: 1.3em;
    }
  }
</style>
<script>
  export default {
    methods: {
      onGoBack(e) {
        e.preventDefault()
        window.history.back();
      }
    }
  }
</script>