Structured DNS error draft

<div class="n-demo"><div class="n-head"><strong>FILTERED DNS RESPONSE</strong><span>LIVE TRACE</span></div><div class="n-stage"><div class="sde"><div class="sde-query n-box">query + SDE option</div><div id="sde-result" class="sde-result n-box"><b id="sde-head">DNS: FILTERED</b><span id="sde-detail">no reason shown</span></div><div class="sde-footer" id="sde-footer">basic error</div></div></div><div class="n-foot">tap to step · auto replay</div></div>

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let step=0;function advance(){const structured=step===1;document.getElementById('sde-detail').textContent=structured?'reason: network policy':'no reason shown';document.getElementById('sde-result').classList.toggle('n-on',structured);document.getElementById('sde-footer').textContent=structured?'structured EDE detail':'basic error';step=(step+1)%2}
const clickTarget=document.querySelector('.n-demo');if(clickTarget&&typeof advance==='function'){advance();const timer=setInterval(advance,1050);clickTarget.addEventListener('pointerdown',()=>{clearInterval(timer);advance()})}