<zk>
    <div style="background-color: lightcoral;">
        <combobutton label="button" />
        gap at bottom / drop shadow missing
    </div>
    <separator/>
    <div style="background-color: lightcoral;">
        <combobutton label="button" />
        <button label="button"/>
        buttons don't align
    </div>
</zk>