<div class="b-header">
  <nav class="navbar navbar-expand-lg navbar-light">
    <div class="container">
      <?php 
      if(has_custom_logo()):
        the_custom_logo();
      else:    
        ?>
          <h1 class="site-title"><a href="<?php echo esc_url(home_url());?>" class="navbar-brand"><?php bloginfo('title');?></a></h1>
      <?php endif;?>
      <button class="navbar-toggler" type="button" data-toggle="collapse" data-target="#navbarSupportedContent" aria-controls="navbarSupportedContent" aria-expanded="false">
        <div id="nav-icon3">
          <span></span>
          <span></span>
          <span></span>
          <span></span>
        </div>
      </button>

      <?php
      if ( has_nav_menu( 'primary' ) ) :
        wp_nav_menu( array(
          'theme_location'    => 'primary',
          'depth'             => 7,
          'menu_class'        => 'navbar-nav ml-auto',
          'container_class' => 'collapse navbar-collapse',
          'container_id' => 'navbarSupportedContent', 
          'fallback_cb'       => 'educational_navwalker::fallback',
          'walker'            => new educational_navwalker(),
        ));
        ?>
       <?php endif; ?>
     </div>
   </nav>
 </div>