<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
    <title>Feeder</title>
    <%= csrf_meta_tags %>
  </head>

  <body>
  <div class="wrapper wrapper--admin">
    <nav class="navbar navbar-default navbar-static-top">
      <div class="container">
        <div class="navbar-header">
          <button type="button" class="navbar-toggle" data-toggle="collapse" data-target="#the-navbar">
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
            <span class="icon-bar"></span>
          </button>
          <a class="navbar-brand" href="/">FreeFeed Feeder Status</a>
        </div>
      </div>
    </nav>
    <div class="container">
      <div class="row">
        <div class="col-lg-12">
          <%= yield %>
        </div>
      </div>
    </div>
  </div>
  <%= render(partial: 'partials/yandex_metrika') if Rails.env.production? %>
  </body>
</html>

<!DOCTYPE html>
<html>
  <head>
    <meta name="viewport" content="width=device-width, initial-scale=1, maximum-scale=1">
    <title>Feeder</title>
    <%= csrf_meta_tags %>
  </head>
  <body>
  <div class="wrapper wrapper--admin">
    <nav class="navbar navbar-expand-lg navbar-light bg-light">
      <div class="container">
        <a class="navbar-brand" href="#">FreeFeed Feeder Status</a>
      </div>
    </nav>
    <div class="container">
      <div class="row">
        <div class="col-lg-12">
          <%= yield %>
        </div>
      </div>
    </div>
  </div>
  <%= render(partial: 'partials/yandex_metrika') if Rails.env.production? %>
  </body>
</html>

Replace navbar with Bootstrap 4 markup
Replace navbar with Bootstrap 4 markup
