So you've spent time making your integration look amazing or your new theme but for some reason the content doesn't look right; it's all crammed into a small width and not the full-width of the screen.

To do this find:

<div class="container-md">
            <div class="row<?php echo (!$this->Html->ifSet($show_header, true) ? ' login' : '');?>">

Replace the whole section with:

<?php
          if (strpos($_SERVER['REQUEST_URI'], "client") && $page_title != "Log In" && $page_title != "Reset Password" && $page_title != "Forgot Username" && $page_title != "Forgot Username" ||
              strpos($_SERVER['REQUEST_URI'], "order") || strpos($_SERVER['REQUEST_URI'], "plugin") || strpos($_SERVER['REQUEST_URI'], "blog") !== false){
        ?>
        <div class="container-md">
          <div class="row<?php echo (!$this->Html->ifSet($show_header, true) ? ' login' : '');?>">
        <?php } ?>
                <?php
                if (!empty($active_nav['secondary'])) {
                ?>
                    <div class="col-md-3">
                        <div class="list-group">
                            <?php
                            foreach ($active_nav['secondary'] as $link => $value) {
                            ?>
                                <a href="<?php $this->Html->_($link);?>" class="list-group-item list-group-item-action <?php echo ($value['active'] ? 'active' : '');?>">
                                    <i class="<?php $this->Html->_($value['icon']);?> fa-fw"></i>
                                    <?php
                                    $this->Html->_($value['name']);
                                    ?>
                                </a>
                            <?php
                            }
                            ?>
                        </div>
                    </div>
                    <div class="col-md-9">
                        <div class="row">
                            <?php echo $content;?>
                        </div>
                    </div>
                <?php
                } else {
                    echo $content;
                }
                ?>
        <?php
            if (strpos($_SERVER['REQUEST_URI'], "client") && $page_title != "Log In" && $page_title != "Reset Password" ||
            strpos($_SERVER['REQUEST_URI'], "order") || strpos($_SERVER['REQUEST_URI'], "plugin") || strpos($_SERVER['REQUEST_URI'], "blog") !== false){
        ?>
            </div>
          </div>
        <?php } ?>