fix: 译文按钮改为 iframe 内嵌显示（与原文一致）

static/app.js

@@ -153,7 +153,10 @@ function renderPaper(p) {
   else if (p.arxiv) links.push(`<a class="paper-link" href="https://arxiv.org/abs/${p.arxiv}" target="_blank">📋 arXiv</a>`);
   // Show translation button for ALL papers with arxiv or pdf
   const paperId = p.arxiv || (p.pdf ? p.pdf.split('/').pop().replace('.pdf','') : null);
-  if (paperId) links.push(`<a class="paper-link trans-btn" href="/papers/translated/${paperId}.pdf" target="_blank" title="中文译文">📖 译文</a>`);
+  if (paperId) {
+    const transUrl = `/papers/translated/${paperId}.pdf`;
+    links.push(`<button class="paper-link trans-btn" data-pdf="${encodeURIComponent(transUrl)}" data-title="${encodeURIComponent(p.title + ' [中文译文]')}" onclick="openPdfBtn(this)">📖 译文</button>`);
+  }
   return `<div class="paper-item"><div class="paper-year">${p.year||'—'}</div><div class="paper-body" id="${id}">
     <div class="paper-title">${p.title}</div>
     <div class="paper-meta"><span>${p.authors||''}</span>${p.venue?`<span class="paper-venue">${p.venue}</span>`:''}${tags}</div>