<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">

    <title>Letter preview</title>

    <style type="text/css">
    body {
      background-color: #dee0e2;
      margin: 0;
    }
      img {
        display: block;
        background-color: #fff;
        width: 100%;
        height: auto;
      }
      .letter-postage,
      .visually-hidden {
        display: none;
      }
    </style>

  </head>

  <body>
    {{ template }}
  </body>

</html>

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="utf-8">

    <title>Letter preview</title>

    <style type="text/css">
    body {
      background-color: #dee0e2;
      margin: 0;
    }
      img {
        display: block;
        background-color: #fff;
        width: 100%;
        height: auto;
      }
      .letter-postage,
      .govuk-visually-hidden {
        display: none;
      }
    </style>

  </head>

  <body>
    {{ template }}
  </body>

</html>

Fix visible hidden content in letter logo preview
Fix visible hidden content in letter logo preview

Presumably the `{{ template }}` is now using new GOV.UK Design System classes, so is no longer targeted by `.visually` hidden