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<style>
    body { font-family: 'Ahem'; color:green }
    .hang { hanging-punctuation: first; margin:1em }
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<body>
<div style="float:left" class="hang">    (Hang test)</div>
<div style="clear:both">
<div class="hang">    (This should hang.<br>(This should not.</div>
<div class="hang" style="text-align:justify; width:300px;">   (This should hang and justifybecause and now were fine.</div>
<div class="hang" style="text-align:justify; width:300px;">   <span>   (</span>This should hang.</div>
<div class="hang" style="text-align:justify; width:300px;">   <span style="border-left:1em solid blue">  (</span>This should not hang.</div>
<div class="hang" style="text-indent:2em; text-align:justify; width:300px;">   (This should hang into the text-indent.</div>