CocoClassHelpDocs/.vitepress/theme/custom-doc.scss

.vp-doc {
  figure {
    text-align: -webkit-center;

    figcaption {
      color: var(--vp-c-text-3);
      font-size: 0.875em;
      margin-top: 5px;
    }
  }

  video {
    margin: auto;
  }
}