I modified header fragment but now its not showing in small devices

Summary:

Hi All, I'm new to visual builder.

I have modified header fragment like below and added css but now header not showing in smaller devices. Please help

-----------------header fragment code----------------

<header role="banner" class="oj-sm-flex-initial vb-web-applayout-header oj-sm-only-hide vb-custom-header-style-01">

  <div class="oj-flex-bar oj-sm-align-items-center vb-web-applayout-header-content">

    <!-- Company logo and application title only displayed in desktop mode -->

    <div class="oj-flex-bar-middle oj-sm-margin-4x-horizontal oj-sm-align-items-center">

      <!-- Please Change the following for company specific logo   -->

      <div class="oj-flex-bar-start">

        <img id="img--38590647-1" :src="[[ $application.path + 'resources/images/WhiteLogo.png' ]]"

          alt="Company logo" height="50">

      </div>

      <h1 class="oj-typography-body-md oj-sm-margin-4x oj-typography-heading-2xl oj-typography-bold vb-custom-header-title-01"