如何在xul文件中设置复选框标签宽度？

<?xml version="1.0"?>
<?xml-stylesheet href="chrome://global/skin/" type="text/css"?>
<?xml-stylesheet href="chrome://zotero-platform/content/preferences.css"?>

<!DOCTYPE window SYSTEM "chrome://zoteroupdateifs/locale/options.dtd">

<!--给作者加粗加星-->

<dialog xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul"
    xmlns:html="http://www.w3.org/1999/xhtml"
    id="updateifs-test"
    title="&author-process-win;"
    width="200"
    height="300"
    style="padding: 10px;"
    buttons="accept,cancel"
    ondialogaccept=" window.close();"
    ondialogcancel="window.close();">
   
    <stringbundleset id="stringbundleset">
            <stringbundle id="updateifs-options" src="chrome://zotero-updateifs/locale/options.properties"/>
      </stringbundleset>
         
            <groupbox  width="200">
              <caption label="&update-abbr;"/>
              <separator class='thin'/> 
              <description style="width: 220px">&update-journal-abbr;</description>
              <separator class='thin'/> 
              <hbox style="margin: 0" width="200">
                <checkbox id="id-updateifs-add-update" label="&add-update;" />
              </hbox>
              <separator class='thin'/> 
              <hbox style="margin: 0" maxwidth="200">
                <checkbox id="id-updateifs-en-abbr" minwidth ='200' label="&en_abbr;"/>
              </hbox>
              <separator class='thin'/> 
              <hbox style="margin: 0" maxwidth="200">
                <checkbox id="id-updateifs-ch-abbr" minwidth ='200' label="&ch_abbr;" />
              </hbox>
            </groupbox>
        
  <script src="options.js"/>
  
  <script
    type="application/x-javascript"
    src="chrome://zoteroupdateifs/content/scripts/options.js"/>

  <script src="chrome://zotero/content/include.js"/>


</dialog>