<div class="spectrum-Tray-wrapper spectrum-CSSExample-dialog">
  <div class="spectrum-Modal spectrum-Tray is-open spectrum-Tray " style="max-height: calc(1149px - var(--spectrum-tray-margin-top));">
    <section class="spectrum-Dialog spectrum-Dialog--large" role="dialog" tabindex="-1" aria-modal="true">
      <div class="spectrum-Dialog-grid">
        <h1 class="spectrum-Dialog-heading spectrum-Dialog-heading--noHeader">New Messages</h1>
        <hr class="spectrum-Divider spectrum-Divider--sizeM spectrum-Divider--horizontal spectrum-Dialog-divider">
        <section class="spectrum-Dialog-content">You have 5 new messages.</section>
      </div>
    </section>
  </div>
</div>