a css class tool.
npm css-class-tool
<style>
.ht.selected{
background:lavender;
}
</style>
<script>
css_class_tool = require("css-class-tool");
</script>
<span class='ht selected'>css .ht.selected style sample</span>
<div>
<span>111 </span><span>222 </span><span>333 </span><span>444 </span><br>
<!-- setClass(elList, addClassList, removeClassList, toggleClassList, framePrefix)-->
<label><input type=checkbox
onchange="var chs=parentNode.parentNode.childNodes;
css_class_tool([chs[0],chs[2]],this.checked?'selected':'',this.checked?'':'selected',null,'ht');
css_class_tool([chs[1],chs[3]],this.checked?'':'selected',this.checked?'selected':'',null,'ht');"
></input>toggle by set()</label><br>
<!-- var setClassByElement(classList, addElList, removeElList, toggleElList, framePrefix) -->
<label><input type=checkbox
onchange="var chs=parentNode.parentNode.childNodes;
css_class_tool.setEl('selected',this.checked?[chs[0],chs[2]]:[chs[1],chs[3]],
this.checked?[chs[1],chs[3]]:[chs[0],chs[2]],null,'ht');"
></input>toggle by setEl()</label><br>
<label><input type=checkbox
onchange="var chs=parentNode.parentNode.childNodes;
css_class_tool.setEl('selected',null,null,[chs[0],chs[1],chs[2],chs[3]]);"
></input>setEl() toggle //may fail at firstly click</label><br>
</div>;