diff --git a/static/css/style.css b/static/css/style.css
index bd71f50..074b313 100644
--- a/static/css/style.css
+++ b/static/css/style.css
@@ -48,6 +48,81 @@
     margin-bottom: 1em;
 }
 
+/* Markdown rendered content (inside review suggestions) */
+.review-content .md-code-block {
+    background: #1e293b;
+    color: #e2e8f0;
+    padding: 12px 14px;
+    border-radius: 6px;
+    overflow-x: auto;
+    margin: 8px 0;
+    font-size: 12px;
+    line-height: 1.5;
+    font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
+}
+.review-content .md-code-block[data-lang]::before {
+    content: attr(data-lang);
+    display: block;
+    font-size: 10px;
+    color: #94a3b8;
+    margin-bottom: 4px;
+    text-transform: uppercase;
+    letter-spacing: 0.05em;
+}
+.review-content .md-inline-code {
+    background: #f1f5f9;
+    padding: 1px 5px;
+    border-radius: 4px;
+    font-size: 0.88em;
+    font-family: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
+    color: #be185d;
+}
+.review-content .md-p {
+    margin: 6px 0;
+    line-height: 1.6;
+}
+.review-content .md-h1, .review-content .md-h2, .review-content .md-h3 {
+    font-weight: 600;
+    margin: 10px 0 4px;
+}
+.review-content .md-h1 { font-size: 1.2em; }
+.review-content .md-h2 { font-size: 1.1em; }
+.review-content .md-h3 { font-size: 1em; }
+.review-content .md-ul, .review-content .md-ol {
+    margin: 6px 0;
+    padding-left: 20px;
+}
+.review-content .md-li {
+    margin: 2px 0;
+    line-height: 1.5;
+}
+.review-content .md-link {
+    color: #2563eb;
+    text-decoration: underline;
+}
+.review-content .md-link:hover {
+    color: #1d4ed8;
+}
+.review-content .md-blockquote {
+    border-left: 3px solid #d1d5db;
+    padding-left: 12px;
+    color: #6b7280;
+    margin: 8px 0;
+    font-style: italic;
+}
+.review-content .md-hr {
+    border: none;
+    border-top: 1px solid #e5e7eb;
+    margin: 12px 0;
+}
+.review-content em {
+    font-style: italic;
+}
+.review-content del {
+    text-decoration: line-through;
+    color: #9ca3af;
+}
+
 /* Severity badge colors (used by review) */
 .border-red-400 { border-color: #f87171; }
 .border-yellow-400 { border-color: #facc15; }
diff --git a/static/js/markdown.js b/static/js/markdown.js
new file mode 100644
index 0000000..7c5656d
--- /dev/null
+++ b/static/js/markdown.js
@@ -0,0 +1,160 @@
+// Shared Markdown renderer for PR-Helper
+// Supports: fenced code blocks, inline code, bold, italic, strikethrough,
+// headers, links, lists (bullet + numbered + nested), blockquotes, horizontal rules
+const Markdown = {
+    render(text) {
+        if (!text) return '';
+        // Normalize line endings
+        text = text.replace(/\r\n/g, '\n');
+
+        // Phase 1: Extract fenced code blocks to protect them
+        const codeBlocks = [];
+        text = text.replace(/```(\w*)\n([\s\S]*?)```/g, (_, lang, code) => {
+            const idx = codeBlocks.length;
+            codeBlocks.push({ lang, code });
+            return `\x00CODEBLOCK_${idx}\x00`;
+        });
+
+        // Phase 2: Extract inline code
+        const inlineCodes = [];
+        text = text.replace(/`([^`\n]+?)`/g, (_, code) => {
+            const idx = inlineCodes.length;
+            inlineCodes.push(code);
+            return `\x00INLINECODE_${idx}\x00`;
+        });
+
+        // Phase 3: Escape HTML
+        text = text
+            .replace(/&/g, '&')
+            .replace(/</g, '&lt;')
+            .replace(/>/g, '&gt;');
+
+        // Phase 4: Block-level processing (split into blocks by blank lines)
+        const blocks = text.split(/\n{2,}/);
+        const htmlBlocks = blocks.map(block => this._renderBlock(block.trim()));
+        text = htmlBlocks.join('\n');
+
+        // Phase 5: Restore fenced code blocks
+        codeBlocks.forEach((cb, idx) => {
+            const langLabel = cb.lang ? ` data-lang="${cb.lang}"` : '';
+            const escaped = this._escapeHtml(cb.code.replace(/\n$/, ''));
+            const replacement = `<pre class="md-code-block"${langLabel}><code>${escaped}</code></pre>`;
+            text = text.replace(`\x00CODEBLOCK_${idx}\x00`, replacement);
+        });
+
+        // Phase 6: Restore inline code
+        inlineCodes.forEach((code, idx) => {
+            const escaped = this._escapeHtml(code);
+            const replacement = `<code class="md-inline-code">${escaped}</code>`;
+            text = text.replace(`\x00INLINECODE_${idx}\x00`, replacement);
+        });
+
+        // Phase 7: Cleanup placeholder newlines
+        text = text.replace(/\x01NL\x01/g, '\n');
+
+        return text;
+    },
+
+    _renderBlock(block) {
+        if (!block) return '';
+
+        // Horizontal rule
+        if (/^(-{3,}|\*{3,}|_{3,})$/.test(block)) {
+            return '<hr class="md-hr">';
+        }
+
+        // Headers
+        const headerMatch = block.match(/^(#{1,6}) (.+)$/);
+        if (headerMatch) {
+            const level = headerMatch[1].length;
+            const content = this._renderInline(headerMatch[2]);
+            return `<h${level} class="md-h${level}">${content}</h${level}>`;
+        }
+
+        // Blockquote
+        if (/^&gt;\s?/.test(block)) {
+            const inner = block.replace(/^&gt;\s?/gm, '').trim();
+            return `<blockquote class="md-blockquote">${this._renderInline(inner)}</blockquote>`;
+        }
+
+        // Unordered list
+        if (/^[\-\*]\s/.test(block)) {
+            return this._renderList(block, 'ul');
+        }
+
+        // Ordered list
+        if (/^\d+\.\s/.test(block)) {
+            return this._renderList(block, 'ol');
+        }
+
+        // Paragraph
+        return `<p class="md-p">${this._renderInline(block)}</p>`;
+    },
+
+    _renderList(block, tag) {
+        const lines = block.split('\n');
+        const items = [];
+        let currentItem = '';
+
+        for (const line of lines) {
+            const itemMatch = line.match(/^[\s]*(?:[\-\*]|\d+\.)\s+(.*)$/);
+            if (itemMatch) {
+                if (currentItem) items.push(currentItem);
+                currentItem = itemMatch[1];
+            } else if (currentItem) {
+                // Continuation of previous item
+                currentItem += ' ' + line.trim();
+            }
+        }
+        if (currentItem) items.push(currentItem);
+
+        const listItems = items.map(item => `<li class="md-li">${this._renderInline(item)}</li>`).join('');
+        return `<${tag} class="md-${tag}">${listItems}</${tag}>`;
+    },
+
+    _renderInline(text) {
+        if (!text) return '';
+
+        // Links: [text](url)
+        text = text.replace(/\[([^\]]+)\]\(([^)]+)\)/g, '<a href="$2" class="md-link" target="_blank" rel="noopener">$1</a>');
+
+        // Images: ![alt](url)
+        text = text.replace(/!\[([^\]]*)\]\(([^)]+)\)/g, '<img src="$2" alt="$1" class="md-img">');
+
+        // Bold + italic: ***text*** or ___text___
+        text = text.replace(/\*{3}(.+?)\*{3}/g, '<strong><em>$1</em></strong>');
+        text = text.replace(/_{3}(.+?)_{3}/g, '<strong><em>$1</em></strong>');
+
+        // Bold: **text** or __text__
+        text = text.replace(/\*{2}(.+?)\*{2}/g, '<strong>$1</strong>');
+        text = text.replace(/_{2}(.+?)_{2}/g, '<strong>$1</strong>');
+
+        // Italic: *text* or _text_
+        text = text.replace(/\*([^\s*](?:[^*]*[^\s*])?)\*/g, '<em>$1</em>');
+        text = text.replace(/_([^\s_](?:[^_]*[^\s_])?)_/g, '<em>$1</em>');
+
+        // Strikethrough: ~~text~~
+        text = text.replace(/~~(.+?)~~/g, '<del>$1</del>');
+
+        // Single newlines within a block become <br>
+        text = text.replace(/\n/g, '<br>');
+
+        return text;
+    },
+
+    _escapeHtml(text) {
+        return text
+            .replace(/&/g, '&amp;')
+            .replace(/</g, '&lt;')
+            .replace(/>/g, '&gt;')
+            .replace(/"/g, '&quot;');
+    }
+};
+
+// Expose globally
+window.Markdown = Markdown;
+
+// Backward-compatible alias
+if (typeof window.renderMarkdown !== 'function') {
+    window.renderMarkdown = function(text) { return Markdown.render(text); };
+}
diff --git a/templates/pages/generate.html b/templates/pages/generate.html
index 8354495..013bc2a 100644
--- a/templates/pages/generate.html
+++ b/templates/pages/generate.html
@@ -3,6 +3,7 @@
 <head>
     {{template "head" .}}
     <script src="/static/js/sse.js"></script>
+    <script src="/static/js/markdown.js"></script>
 </head>
 <body class="bg-gray-50 min-h-screen">
     {{template "nav" .}}
@@ -266,28 +267,9 @@
             });
         }
 
-        // Simple markdown rendering (bold, headers, lists, code)
+        // Markdown rendering (delegates to shared Markdown.render)
         function renderMarkdown(text) {
-            if (!text) return '';
-            let html = text
-                .replace(/&/g, '&amp;')
-                .replace(/</g, '&lt;')
-                .replace(/>/g, '&gt;')
-                .replace(/^### (.+)$/gm, '<h3>$1</h3>')
-                .replace(/^## (.+)$/gm, '<h2>$1</h2>')
-                .replace(/^# (.+)$/gm, '<h1>$1</h1>')
-                .replace(/\*\*(.+?)\*\*/g, '<strong>$1</strong>')
-                .replace(/`(.+?)`/g, '<code class="bg-gray-100 px-1 rounded">$1</code>')
-                .replace(/^- (.+)$/gm, '<li class="bullet-item">$1</li>')
-                .replace(/^(\d+)\. (.+)$/gm, '<li class="numbered-item">$2</li>')
-                .replace(/\n/g, '\n');
-            // Wrap consecutive bullet <li> in <ul>
-            html = html.replace(/((?:<li class="bullet-item">.*<\/li>\n?)+)/g, '<ul>$1</ul>');
-            // Wrap consecutive numbered <li> in <ol>
-            html = html.replace(/((?:<li class="numbered-item">.*<\/li>\n?)+)/g, '<ol>$1</ol>');
-            // Convert remaining newlines to <br> (outside lists)
-            html = html.replace(/\n/g, '<br>');
-            return html;
+            return Markdown.render(text);
         }
 
         function copyMarkdown() {
diff --git a/templates/pages/repo.html b/templates/pages/repo.html
index 91ec64e..a11139b 100644
--- a/templates/pages/repo.html
+++ b/templates/pages/repo.html
@@ -8,6 +8,7 @@
     <script src="/static/lib/highlight.min.js"></script>
     <script src="/static/js/sse.js"></script>
     <script src="/static/js/graph.js"></script>
+    <script src="/static/js/markdown.js"></script>
     <script src="/static/js/diff-viewer.js"></script>
     <script src="/static/js/review-inline.js"></script>
     <style>
@@ -552,17 +553,7 @@
         }
 
         function renderInlineMarkdown(text) {
-            if (!text) return '';
-            return text
-                .replace(/&/g, '&amp;')
-                .replace(/</g, '&lt;')
-                .replace(/>/g, '&gt;')
-                .replace(/^### (.+)$/gm, '<h3 class="font-semibold text-sm mt-2">$1</h3>')
-                .replace(/^## (.+)$/gm, '<h2 class="font-semibold mt-2">$1</h2>')
-                .replace(/\*\*(.+?)\*\*/g, '<strong>$1</strong>')
-                .replace(/`(.+?)`/g, '<code class="bg-gray-100 px-1 rounded text-xs">$1</code>')
-                .replace(/^- (.+)$/gm, '<li class="ml-4">$1</li>')
-                .replace(/\n/g, '<br>');
+            return Markdown.render(text);
         }
 
         init();
diff --git a/templates/pages/review.html b/templates/pages/review.html
index dc8ff74..2351db3 100644
--- a/templates/pages/review.html
+++ b/templates/pages/review.html
@@ -6,6 +6,7 @@
     <script src="/static/lib/diff2html.min.js"></script>
     <script src="/static/lib/highlight.min.js"></script>
     <script src="/static/js/sse.js"></script>
+    <script src="/static/js/markdown.js"></script>
     <script src="/static/js/diff-viewer.js"></script>
     <script src="/static/js/review-inline.js"></script>
     <script src="/static/js/note-editor.js"></script>
@@ -418,28 +419,9 @@
             btn.textContent = diffVisible ? '隐藏 Diff' : '显示 Diff';
         }
 
-        // Simple markdown rendering
+        // Markdown rendering (delegates to shared Markdown.render)
         function renderMarkdown(text) {
-            if (!text) return '';
-            let html = text
-                .replace(/&/g, '&amp;')
-                .replace(/</g, '&lt;')
-                .replace(/>/g, '&gt;')
-                .replace(/^### (.+)$/gm, '<h3>$1</h3>')
-                .replace(/^## (.+)$/gm, '<h2>$1</h2>')
-                .replace(/^# (.+)$/gm, '<h1>$1</h1>')
-                .replace(/\*\*(.+?)\*\*/g, '<strong>$1</strong>')
-                .replace(/`(.+?)`/g, '<code class="bg-gray-100 px-1 rounded">$1</code>')
-                .replace(/^- (.+)$/gm, '<li class="bullet-item">$1</li>')
-                .replace(/^(\d+)\. (.+)$/gm, '<li class="numbered-item">$2</li>')
-                .replace(/\n/g, '\n');
-            // Wrap consecutive bullet <li> in <ul>
-            html = html.replace(/((?:<li class="bullet-item">.*<\/li>\n?)+)/g, '<ul>$1</ul>');
-            // Wrap consecutive numbered <li> in <ol>
-            html = html.replace(/((?:<li class="numbered-item">.*<\/li>\n?)+)/g, '<ol>$1</ol>');
-            // Convert remaining newlines to <br> (outside lists)
-            html = html.replace(/\n/g, '<br>');
-            return html;
+            return Markdown.render(text);
         }
 
         // ── History loading ────────────────────────────────────────