Step #4

uniquely named shared elements

<div class="PostItem Card">
  <img src="…" style="view-transition-name: {page-slug}-image" />
  <h2 style="view-transition-name: {page-slug}-title">…</h2>
</div>

<main class="PostDetail">
  <img src="…" style="view-transition-name: {page-slug}-image" />
  <h1 style="view-transition-name: {page-slug}-title">…</h2>
</main>