diff --git a/packages/email-renderer/package.json b/packages/email-renderer/package.json
index 5c7cca90..9f3f2712 100644
--- a/packages/email-renderer/package.json
+++ b/packages/email-renderer/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@wrnexus/email-renderer",
-  "version": "0.1.17",
+  "version": "0.1.18",
   "type": "module",
   "description": "WRNexus block email renderers with HTML, text, AMP Email, and MJML interoperability.",
   "exports": {
diff --git a/packages/email-renderer/src/blocks.ts b/packages/email-renderer/src/blocks.ts
index 232cbb1b..090b02e9 100644
--- a/packages/email-renderer/src/blocks.ts
+++ b/packages/email-renderer/src/blocks.ts
@@ -204,7 +204,7 @@ export const columnsBlock = defineBlock({
         node,
       ),
     ampEmail: ({ node, slots }) =>
-      emailCell(`<table role="presentation" width="100%"><tr>${slots.columns}</tr></table>`, node),
+      emailCell(`<table role="presentation" width="100%"><tr class="wrn-columns">${slots.columns}</tr></table>`, node),
     mjml: ({ slots }) => slots.columns,
   },
   textRenderer: ({ slots }) => slots.columns,
@@ -234,7 +234,7 @@ export const columnBlock = defineBlock({
     emailHtml: ({ node, slots }) =>
       `<td data-block-id="${html(node.id)}" class="wrn-column" width="${html(attrs(node).width)}" valign="top"><table role="presentation" width="100%" cellpadding="0" cellspacing="0" border="0">${slots.content}</table></td>`,
     ampEmail: ({ node, slots }) =>
-      `<td width="${html(attrs(node).width)}" valign="top"><table role="presentation" width="100%" cellpadding="0" cellspacing="0" border="0">${slots.content}</table></td>`,
+      `<td class="wrn-column" width="${html(attrs(node).width)}" valign="top"><table role="presentation" width="100%" cellpadding="0" cellspacing="0" border="0">${slots.content}</table></td>`,
     mjml: ({ node, slots }) =>
       `<mj-column width="${html(attrs(node).width)}">${slots.content}</mj-column>`,
   },
diff --git a/packages/email-renderer/src/email.ts b/packages/email-renderer/src/email.ts
index 2c8df9c1..a26a86b4 100644
--- a/packages/email-renderer/src/email.ts
+++ b/packages/email-renderer/src/email.ts
@@ -81,7 +81,7 @@ const head = (document: BlockDocument, body: string, direction: "ltr" | "rtl") =
 };
 const ampHead = (document: BlockDocument, body: string, direction: "ltr" | "rtl") => {
   const props = document.root.props as Record<string, unknown>;
-  const css = `.marketing-image img{object-fit:contain}body{margin:0;color:${props.textColor ?? "#111827"};font-family:${props.fontFamily ?? "Arial, sans-serif"}}a{color:${props.linkColor ?? "#2563eb"}}.email-bg{background:${props.background ?? "#f3f4f6"}}.email-body{max-width:${props.width ?? "600"}px;width:100%;background:${props.contentBackground ?? "#ffffff"}}`;
+  const css = `@media only screen and (max-width:480px){.email-body .wrn-columns{display:block}.email-body .wrn-column{display:block;width:100%}}.marketing-image img{object-fit:contain}body{margin:0;color:${props.textColor ?? "#111827"};font-family:${props.fontFamily ?? "Arial, sans-serif"}}a{color:${props.linkColor ?? "#2563eb"}}.email-bg{background:${props.background ?? "#f3f4f6"}}.email-body{max-width:${props.width ?? "600"}px;width:100%;background:${props.contentBackground ?? "#ffffff"}}`;
   return `<!doctype html><html amp4email data-css-strict lang="${escapeHtml(document.meta.lang)}" dir="${direction}"><head><meta charset="utf-8"><script async src="https://cdn.ampproject.org/v0.js"></script><style amp4email-boilerplate>body{visibility:hidden}</style><style amp-custom>${css}.section{padding:24px}.button{background:#2563eb;border-radius:6px;color:#fff;display:inline-block;font-weight:700;padding:12px 20px;text-decoration:none}.spacer{height:24px}</style></head><body>${body}</body></html>`;
 };
 
diff --git a/packages/email-renderer/test/email.test.ts b/packages/email-renderer/test/email.test.ts
index ddbad1da..dcfe5790 100644
--- a/packages/email-renderer/test/email.test.ts
+++ b/packages/email-renderer/test/email.test.ts
@@ -62,13 +62,18 @@ describe("email renderer", () => {
       const draft=structuredClone(document);
       const content=draft.root.slots.content[0]!.slots.content;
       draft.root.slots.content[0]!.slots.content=[{id:"columns",type:"layout.columns",version:1,props:{},styles:{},slots:{columns:Array.from({length:count},(_,index)=>({id:`column-${index}`,type:"layout.column",version:1,props:{width:`${100/count}%`},styles:{},slots:{content:index===0?content:[]}}))}}];
-      const result=await renderEmail(draft,{mjml:true});
+      const result=await renderEmail(draft,{mjml:true,amp:true});
       expect(result.ok).toBe(true);
       if(!result.ok)continue;
       const mjml=result.value.exports!.mjml!;
       expect(mjml.match(/<mj-column\b/g)).toHaveLength(count);
       expect(await validateMjml(mjml)).toEqual([]);
       expect(mjml).toContain("Hello &lt;world&gt;");
+      const amp=result.value.parts.amp;
+      expect(amp?.validation.valid).toBe(true);
+      expect(amp?.content.match(/class="wrn-column"/g)).toHaveLength(count);
+      expect(amp?.content).toContain('class="wrn-columns"');
+      expect(amp?.content).toContain('@media only screen and (max-width:480px){.email-body .wrn-columns{display:block}.email-body .wrn-column{display:block;width:100%}}');
     }
   });
   test("global brand logo survives HTML, AMP, and strict MJML export", async () => {