Steps to Reproduce

    <groupbox width="300px" >
        <caption>
            <checkbox id="cb" checked="true" />
            Enable Backups
        </caption>
    </groupbox>

1. run the zul above in iceblue theme

Current Result

the checkmark is shifted to the left a bit

Expected Result

the checkmark should be in the center of the checkbox

Debug info

• breeze has no such issue