PAGE_CONTAINER

            <xf:if is="$sidebar">
                <div class="p-body-sidebar">
                    <xf:ad position="container_sidebar_above" />
                    <xf:foreach loop="$sidebar" value="$sidebarHtml">
                        {$sidebarHtml}
                    </xf:foreach>
                    <xf:ad position="container_sidebar_below" />
                </div>
            </xf:if>

<div class="p-body-content">
                <xf:ad position="container_content_above" />
                <div class="p-body-pageContent">{$content|raw}</div>
                <xf:ad position="container_content_below" />
            </div>

app_body.less

    .p-body-main--withSidebar &
    {
        padding-right: @xf-sidebarSpacer;
    }

.p-body-main--withSidebar &
    {
        padding-left: @xf-sidebarSpacer;
    }