diff --git a/packages/core/src/figma/nodeToHtml.test.ts b/packages/core/src/figma/nodeToHtml.test.ts
index 7f70a61dc..367311474 100644
--- a/packages/core/src/figma/nodeToHtml.test.ts
+++ b/packages/core/src/figma/nodeToHtml.test.ts
@@ -84,6 +84,24 @@ describe("nodeToHtml", () => {
     expect(out.html).not.toContain("left: 520px");
   });
 
+  it("prefixes digit-leading slugs so ids stay CSS-selector-safe", () => {
+    const out = nodeToHtml(
+      frame([
+        {
+          id: "1:2",
+          name: "3D Object - Headphones",
+          type: "RECTANGLE",
+          absoluteBoundingBox: BOX(120, 220, 100, 40),
+          fills: [SOLID_BLUE],
+        },
+      ]),
+      { resolved: [], unresolved: [] },
+    );
+    // "#3d-object-headphones" would throw in querySelector/GSAP targeting
+    expect(out.html).toContain('id="n3d-object-headphones"');
+    expect(out.html).not.toContain('id="3d-object-headphones"');
+  });
+
   it("emits var() with literal fallback for resolved bindings", () => {
     const out = nodeToHtml(
       frame([
diff --git a/packages/core/src/figma/nodeToHtml.ts b/packages/core/src/figma/nodeToHtml.ts
index 6ce0c81d8..393af42c4 100644
--- a/packages/core/src/figma/nodeToHtml.ts
+++ b/packages/core/src/figma/nodeToHtml.ts
@@ -162,7 +162,12 @@ interface RenderContext {
 }
 
 function uniqueSlug(ctx: RenderContext, name: string): string {
-  const base = slugify(name);
+  const raw = slugify(name);
+  // A digit-leading id ("3D Object" → "3d-object") is valid HTML but not a
+  // valid CSS selector — querySelector("#3d-object") throws, which breaks
+  // GSAP targeting and figma-motion translation. Prefix so ids stay
+  // selector-safe.
+  const base = /^[0-9]/.test(raw) ? `n${raw}` : raw;
   let slug = base;
   let n = 2;
   while (ctx.usedSlugs.has(slug)) slug = `${base}-${n++}`;