ot_typo3/ot_widgets/Resources/Private/Templates/Box/Box.html

<f:layout name="Default" />

<f:section name="box">
    <div class="ot-box">
        <header>
            <h3>{title}</h3>
        </header>

        <div class="box-content">
            {content}
        </div>

        <footer>
            {footer}
        </footer>
    </div>
</f:section>