{namespace drk=Drk\Template\ViewHelpers}
<div xmlns="http://www.w3.org/1999/xhtml" lang="en"
      xmlns:f="http://xsd.helhum.io/ns/typo3/cms-fluid/master/ViewHelpers"
      f:schemaLocation="https://fluidtypo3.org/schemas/fluid-master.xsd"
      xmlns:drk="Drk\Template\ViewHelpers"
      data-namespace-typo3-fluid="true">

    <li id="c{accordion.uid}" class="o-accordion__navigation {f:if(condition:'{accordion_iteration.isFirst}', then:' is-active')}">

        <a href="#accordion-content-{accordion.uid}" js-accordion-toggle class="o-accordion__title js-accordion-toggle">
            <span class="o-accordion__title-wrap">
                {accordion.header}
            </span>
        </a>

        <div id="accordion-content-{accordion.uid}" class="o-accordion__content js-accordion-content {f:if(condition:'{accordion_iteration.isFirst}', then:' is-active')}">
            <f:format.raw>
                {drk:arrayIndex(
                object: data,
                index: 'tx_gridelements_view_child_{accordion.uid}')}
            </f:format.raw>
        </div>
    </li>

</div>