<meta http-equiv="Refresh" content="0; url='https://www.domain.tld'" />

<div id="sc-container">
    <div id="sc-branding" class="sc-bb">
        <a target="_blank" href="https://www.speedcheck.org/">
            <img src="https://cdn.speedcheck.org/branding/speedcheck-logo-18.png" alt="Speedcheck"/>
        </a>
    </div>
</div>
<script src="https://cdn.speedcheck.org/basic/scbjs.min.js" async></script>

#sc-container {
        margin: 0 auto;
    width: 200px!important;
    max-width: 200px!important;
    height: 300px!important;
}
#sc-start-button, #sc-details-button {
    cursor: pointer;
    max-width: 200px!important;
}
#sc-results {
    width: auto!important;
    max-width: 200px!important;
}

  /* hide mobile version by default */
  .logo .mobile {
    display: none;
  }
  /* when screen is less than 500px wide
    show mobile version and hide desktop */
  @media (max-width: 500px) {
    .logo .mobile {
      display: block;
    }
    .logo .desktop {
      display: none;
    }
  }

<div class="logo">
  <img src="/images/logo_desktop.png" class="desktop" />
  <img src="/images/logo_mobile.png" class="mobile" />
</div>

{
  "background_color": "navy",
  "description": "Site Description",
  "display": "standalone",
  "icons": [
    {
      "src": "images/app_logo.png",
      "sizes": "200x200",
      "type": "image/png"
    }
  ],
  "name": "Site name",
  "short_name": "App Name",
  "start_url": "https://www.domain.tld/"
}

<link rel="manifest" href="https://www.domain.tld/manifest.json" />