diff --git a/.jules/spider.md b/.jules/spider.md
index 572ac48..94d1fdf 100644
--- a/.jules/spider.md
+++ b/.jules/spider.md
@@ -10,3 +10,6 @@
 ## 2024-05-19 - Typechecking JSON-LD Date Properties
 **Learning:** When passing potentially null date fields (like `publishedAt`, `updatedAt`) from Payload CMS to jsonLd generator functions, using the fields directly can cause strict TypeScript compilation failures since the schemas explicitly expect `string | undefined` and not `null`.
 **Action:** Always use the logical OR operator with `undefined` (e.g., `datePublished: post.publishedAt || undefined`) when passing date properties to JSON-LD generator functions to satisfy strict type requirements and prevent build regressions.
+## 2026-06-22 - Nested Main Tags in Page Layouts
+**Learning:** Detailed page layouts (like `actualites/[slug]/page.tsx`) often define `<main>` as their outermost wrapper. If inner column structures also use `<main>`, it results in invalid HTML5 (nested `<main>` tags). This negatively impacts semantic structure and crawler readability.
+**Action:** When working on page components, always verify the outermost wrapper tag before using `<main>` for inner content areas. Use semantic `<div>` elements for structural grid/column wrappers if a `<main>` or `<article>` wrapper already exists at a higher level.
diff --git a/src/app/(frontend)/[locale]/actualites/[slug]/page.tsx b/src/app/(frontend)/[locale]/actualites/[slug]/page.tsx
index e4026ac..c7fa3dc 100644
--- a/src/app/(frontend)/[locale]/actualites/[slug]/page.tsx
+++ b/src/app/(frontend)/[locale]/actualites/[slug]/page.tsx
@@ -156,7 +156,8 @@ export default async function Actualite({ params: paramsPromise }: Args) {
         </aside>
 
         {/* CENTER COLUMN: Main Article (Left aligned flow) */}
-        <main className="col-span-1 lg:col-span-7">
+        {/* SEO: Changed <main> to <div> to prevent invalid nested <main> tags, improving semantic structure and crawlability. */}
+        <div className="col-span-1 lg:col-span-7">
           <article className="w-full">
             
             {/* Hero Image */}
@@ -254,7 +255,7 @@ export default async function Actualite({ params: paramsPromise }: Args) {
             </div>
             
           </article>
-        </main>
+        </div>
 
         {/* RIGHT COLUMN: Related / Latest News */}
         <aside className="hidden lg:block lg:col-span-3">