diff --git a/apps/landing/public/og-default.png b/apps/landing/public/og-default.png
new file mode 100644
index 0000000..8962500
Binary files /dev/null and b/apps/landing/public/og-default.png differ
diff --git a/apps/landing/src/layouts/Layout.astro b/apps/landing/src/layouts/Layout.astro
index 35c008a..398e612 100644
--- a/apps/landing/src/layouts/Layout.astro
+++ b/apps/landing/src/layouts/Layout.astro
@@ -16,12 +16,20 @@ import { SiteFooter } from "../components/SiteFooter";
 
 const SITE_URL = "https://rubis.pro";
 
+/**
+ * OG image par défaut (1200×630) servie depuis apps/landing/public/.
+ * Utilisée pour les partages sociaux quand aucune image n'est fournie
+ * par la page (cas de la home + pages légales). Les articles de blog
+ * ont leur propre hero qui prend précédence.
+ */
+const DEFAULT_OG_IMAGE = `${SITE_URL}/og-default.png`;
+
 interface Props {
   title: string;
   description: string;
   /** Path absolu de la page courante (ex. "/blog/foo"). Default = location actuelle. */
   pathname?: string;
-  /** OG image absolue (1200×630 idéal). */
+  /** OG image absolue (1200×630 idéal). Fallback sur og-default.png si non fournie. */
   ogImage?: string;
   /** OG type. Default "website". Mettre "article" sur les pages de blog. */
   ogType?: "website" | "article";
@@ -44,7 +52,20 @@ const {
   jsonLd,
 } = Astro.props;
 
-const fullTitle = title.includes("Rubis") ? title : `${title} — Rubis sur l'ongle`;
+/**
+ * Suffixe brand intelligent :
+ *  - Si le titre est court (<45 chars) ET ne contient pas "Rubis", on ajoute
+ *    " — Rubis" pour la cohérence brand dans les SERP.
+ *  - Sinon (titre long ou déjà brandé), on laisse tel quel : Google tronque
+ *    à ~60 chars dans le snippet, autant garder le message-clé en entier.
+ *
+ * Le branding reste assuré par og:site_name + JSON-LD publisher + le hostname
+ * rubis.pro visible dans la SERP — pas besoin de le marteler dans le title.
+ */
+const fullTitle =
+  title.length < 45 && !title.includes("Rubis") ? `${title} — Rubis` : title;
+
+const resolvedOgImage = ogImage ?? DEFAULT_OG_IMAGE;
 const url = `${SITE_URL}${pathname ?? Astro.url.pathname}`;
 const robots = noindex ? "noindex,nofollow" : "index,follow,max-image-preview:large";
 const jsonLdArray = jsonLd ? (Array.isArray(jsonLd) ? jsonLd : [jsonLd]) : [];
@@ -72,22 +93,17 @@ const jsonLdArray = jsonLd ? (Array.isArray(jsonLd) ? jsonLd : [jsonLd]) : [];
     <meta property="og:title" content={fullTitle} />
     <meta property="og:description" content={description} />
     <meta property="og:url" content={url} />
-    {
-      ogImage && (
-        <>
-          <meta property="og:image" content={ogImage} />
-          <meta property="og:image:width" content="1200" />
-          <meta property="og:image:height" content="630" />
-          <meta property="og:image:alt" content={title} />
-        </>
-      )
-    }
+    <meta property="og:image" content={resolvedOgImage} />
+    <meta property="og:image:width" content="1200" />
+    <meta property="og:image:height" content="630" />
+    <meta property="og:image:alt" content={title} />
 
-    {/* Twitter Card */}
-    <meta name="twitter:card" content={ogImage ? "summary_large_image" : "summary"} />
+    {/* Twitter Card — toujours summary_large_image puisqu'on a maintenant
+        un og-default.png 1200×630 servi par défaut sur les pages sans hero. */}
+    <meta name="twitter:card" content="summary_large_image" />
     <meta name="twitter:title" content={fullTitle} />
     <meta name="twitter:description" content={description} />
-    {ogImage && <meta name="twitter:image" content={ogImage} />}
+    <meta name="twitter:image" content={resolvedOgImage} />
 
     {/* Favicons */}
     <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
diff --git a/docs/marketing/assets/og-default.html b/docs/marketing/assets/og-default.html
new file mode 100644
index 0000000..efd19d1
--- /dev/null
+++ b/docs/marketing/assets/og-default.html
@@ -0,0 +1,425 @@
+<!doctype html>
+<!--
+  OG image par défaut — 1200 × 630 px (ratio 1.91:1, standard Open Graph).
+  Servie sur rubis.pro/og-default.png par Astro static (apps/landing/public/).
+
+  Pourquoi ce ratio :
+   - Facebook / LinkedIn / Twitter / Slack utilisent tous le carrousel
+     1200 × 630 (~1.91:1) pour les preview cards.
+   - Les images plus larges (LinkedIn banner 1584 × 280) sont rognées en
+     preview car le viewport square les recoupe.
+
+  Ouvre ce fichier dans Chrome et clique :
+   - "Télécharger PNG" → og-default.png, prêt à poser dans
+     apps/landing/public/og-default.png
+
+  La page est volontairement BUSY (mock card visible, tagline complète) —
+  l'objectif est de transmettre le produit en un coup d'œil quand quelqu'un
+  partage rubis.pro sur LinkedIn / X / Slack / iMessage.
+-->
+<html lang="fr">
+  <head>
+    <meta charset="UTF-8" />
+    <title>OG image par défaut — Rubis sur l'ongle</title>
+    <link rel="preconnect" href="https://fonts.googleapis.com" />
+    <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
+    <link
+      href="https://fonts.googleapis.com/css2?family=Bricolage+Grotesque:opsz,wght@12..96,500;12..96,600;12..96,700;12..96,800&family=Inter:wght@400;500;600;700&display=swap"
+      rel="stylesheet"
+    />
+    <style>
+      :root {
+        --rubis: #9f1239;
+        --rubis-deep: #771328;
+        --rubis-light: #c9415c;
+        --rubis-glow: #fbe4ea;
+        --ink: #1a1410;
+        --ink-2: #4f4640;
+        --ink-3: #8a7f76;
+        --line: #e8e0d6;
+        --cream: #faf7f2;
+        --cream-2: #f5efe7;
+      }
+
+      * { box-sizing: border-box; margin: 0; padding: 0; }
+
+      body {
+        background: #d9d4cb;
+        font-family: "Inter", -apple-system, BlinkMacSystemFont, sans-serif;
+        -webkit-font-smoothing: antialiased;
+        padding: 24px;
+      }
+
+      .controls {
+        display: flex;
+        gap: 12px;
+        margin-bottom: 20px;
+        align-items: center;
+      }
+      .controls h2 {
+        font-family: "Bricolage Grotesque", sans-serif;
+        font-weight: 700;
+        font-size: 18px;
+        color: #1a1410;
+        margin: 0 16px 0 0;
+        letter-spacing: -0.012em;
+      }
+      .btn {
+        display: inline-flex;
+        align-items: center;
+        gap: 8px;
+        padding: 10px 18px;
+        border: none;
+        border-radius: 6px;
+        font-family: "Inter", sans-serif;
+        font-weight: 600;
+        font-size: 14px;
+        cursor: pointer;
+        transition: background 0.15s, transform 0.1s;
+      }
+      .btn-primary {
+        background: #9f1239;
+        color: white;
+        box-shadow: 0 2px 6px rgba(159, 18, 57, 0.25);
+      }
+      .btn-primary:hover { background: #771328; transform: translateY(-1px); }
+      .btn-secondary {
+        background: white;
+        color: #1a1410;
+        border: 1px solid #e8e0d6;
+      }
+      .btn-secondary:hover { background: #faf7f2; }
+      .btn:disabled { opacity: 0.6; cursor: wait; }
+      .hint { font-size: 12.5px; color: #4f4640; margin-left: 8px; }
+
+      /* ===== OG image — 1200 × 630 ===== */
+      .og {
+        width: 1200px;
+        height: 630px;
+        background: var(--cream);
+        position: relative;
+        display: grid;
+        grid-template-columns: 1.15fr 0.85fr;
+        gap: 56px;
+        padding: 64px 72px;
+        overflow: hidden;
+      }
+
+      /* Halo rubis discret en haut-droite */
+      .og::before {
+        content: "";
+        position: absolute;
+        top: -240px;
+        right: -180px;
+        width: 520px;
+        height: 520px;
+        background: radial-gradient(circle, var(--rubis-glow) 0%, transparent 65%);
+        pointer-events: none;
+      }
+      /* Gem watermark très transparent en pied */
+      .og::after {
+        content: "";
+        position: absolute;
+        bottom: -200px;
+        left: 25%;
+        width: 380px;
+        height: 380px;
+        transform: rotate(45deg);
+        background: var(--rubis);
+        opacity: 0.04;
+        border-radius: 28px;
+        pointer-events: none;
+      }
+
+      /* ============== LEFT — brand + tagline ============== */
+      .left {
+        display: flex;
+        flex-direction: column;
+        justify-content: center;
+        z-index: 1;
+        max-width: 580px;
+      }
+      .brand-row {
+        display: flex;
+        align-items: center;
+        gap: 14px;
+        margin-bottom: 28px;
+      }
+      .gem-svg {
+        width: 38px;
+        height: 38px;
+        filter: drop-shadow(0 2px 4px rgba(159, 18, 57, 0.18));
+      }
+      .brand-name {
+        font-family: "Bricolage Grotesque", sans-serif;
+        font-weight: 800;
+        font-size: 28px;
+        color: var(--ink);
+        letter-spacing: -0.02em;
+        line-height: 1;
+      }
+      .brand-name .suffix {
+        font-style: italic;
+        font-weight: 500;
+        color: var(--ink-3);
+        font-size: 18px;
+        margin-left: 4px;
+      }
+
+      .tagline {
+        font-family: "Bricolage Grotesque", sans-serif;
+        font-weight: 700;
+        font-size: 56px;
+        color: var(--ink);
+        line-height: 1.05;
+        letter-spacing: -0.028em;
+      }
+      .tagline em {
+        font-style: italic;
+        color: var(--rubis);
+      }
+
+      .pitch {
+        margin-top: 20px;
+        font-size: 18px;
+        color: var(--ink-2);
+        line-height: 1.5;
+        max-width: 480px;
+      }
+      .pitch b {
+        font-weight: 700;
+        color: var(--ink);
+      }
+
+      .url {
+        margin-top: 32px;
+        display: inline-flex;
+        align-items: center;
+        gap: 10px;
+        font-family: "Bricolage Grotesque", sans-serif;
+        font-weight: 600;
+        font-size: 16px;
+        color: var(--ink-2);
+        background: white;
+        padding: 10px 18px;
+        border-radius: 8px;
+        border: 1px solid var(--line);
+        align-self: flex-start;
+        box-shadow: 0 2px 8px rgba(26, 20, 16, 0.04);
+      }
+      .url::before {
+        content: "";
+        width: 9px;
+        height: 9px;
+        background: var(--rubis);
+        transform: rotate(45deg);
+      }
+
+      /* ============== RIGHT — mock card ============== */
+      .right {
+        display: flex;
+        flex-direction: column;
+        justify-content: center;
+        align-items: flex-end;
+        z-index: 1;
+      }
+
+      .card {
+        width: 100%;
+        max-width: 380px;
+        background: white;
+        border: 1px solid var(--line);
+        border-radius: 18px;
+        padding: 28px 30px;
+        box-shadow:
+          0 24px 48px -16px rgba(26, 20, 16, 0.18),
+          0 6px 12px -4px rgba(26, 20, 16, 0.08);
+      }
+
+      .rubis-hero {
+        display: flex;
+        align-items: center;
+        gap: 18px;
+        padding-bottom: 20px;
+        border-bottom: 1px solid var(--line);
+      }
+      .rubis-hero .gem-big {
+        width: 52px;
+        height: 52px;
+        filter: drop-shadow(0 4px 10px rgba(159, 18, 57, 0.32));
+        flex-shrink: 0;
+      }
+      .rubis-count {
+        font-family: "Bricolage Grotesque", sans-serif;
+        font-weight: 700;
+        font-size: 32px;
+        color: var(--ink);
+        letter-spacing: -0.022em;
+        line-height: 1;
+      }
+      .rubis-sub {
+        font-size: 14px;
+        color: var(--ink-2);
+        margin-top: 6px;
+        line-height: 1.4;
+      }
+      .rubis-sub b { font-weight: 600; color: var(--ink); }
+
+      .kpis {
+        display: grid;
+        grid-template-columns: 1fr 1fr;
+        gap: 22px;
+        margin-top: 20px;
+      }
+      .kpi-label {
+        font-size: 11px;
+        color: var(--ink-3);
+        text-transform: uppercase;
+        letter-spacing: 0.08em;
+        font-weight: 600;
+      }
+      .kpi-value {
+        font-family: "Bricolage Grotesque", sans-serif;
+        font-weight: 700;
+        font-size: 22px;
+        color: var(--ink);
+        letter-spacing: -0.015em;
+        margin-top: 5px;
+        font-variant-numeric: tabular-nums;
+      }
+      .kpi-delta {
+        font-size: 12px;
+        color: var(--rubis);
+        font-weight: 500;
+        margin-top: 3px;
+      }
+
+      .activity {
+        margin-top: 18px;
+        padding-top: 14px;
+        border-top: 1px dashed var(--line);
+        font-size: 12.5px;
+        color: var(--ink-2);
+        display: flex;
+        justify-content: space-between;
+        align-items: baseline;
+      }
+      .activity b { color: var(--ink); font-weight: 600; }
+      .activity time { color: var(--ink-3); font-size: 11.5px; font-variant-numeric: tabular-nums; }
+    </style>
+  </head>
+
+  <body>
+    <div class="controls">
+      <h2>OG image — 1200 × 630</h2>
+      <button id="exportPng" class="btn btn-primary">🖼️ Télécharger og-default.png</button>
+      <span class="hint">Pose ensuite dans <code>apps/landing/public/og-default.png</code></span>
+    </div>
+
+    <div class="og">
+      <!-- ============ LEFT ============ -->
+      <div class="left">
+        <div class="brand-row">
+          <svg class="gem-svg" viewBox="0 0 100 100" xmlns="http://www.w3.org/2000/svg">
+            <polygon points="50,6 6,50 50,50" fill="#9F1239" fill-opacity="1" />
+            <polygon points="50,6 94,50 50,50" fill="#9F1239" fill-opacity="0.8" />
+            <polygon points="6,50 50,50 50,94" fill="#9F1239" fill-opacity="0.65" />
+            <polygon points="50,50 94,50 50,94" fill="#9F1239" fill-opacity="0.48" />
+            <polygon points="50,6 94,50 50,94 6,50" fill="none" stroke="#9F1239" stroke-width="1.6" stroke-linejoin="round" />
+          </svg>
+          <span class="brand-name">Rubis<span class="suffix">sur l'ongle</span></span>
+        </div>
+
+        <h1 class="tagline">
+          Vos factures relancées <em>toutes seules</em>.
+        </h1>
+
+        <p class="pitch">
+          Le SaaS de relance pour TPE-PME françaises. <b>5 heures par semaine</b>
+          récupérées, automatiquement.
+        </p>
+
+        <div class="url">rubis.pro</div>
+      </div>
+
+      <!-- ============ RIGHT — mock card ============ -->
+      <div class="right">
+        <div class="card">
+          <div class="rubis-hero">
+            <svg class="gem-big" viewBox="0 0 100 100">
+              <polygon points="50,6 6,50 50,50" fill="#9F1239" fill-opacity="1" />
+              <polygon points="50,6 94,50 50,50" fill="#9F1239" fill-opacity="0.8" />
+              <polygon points="6,50 50,50 50,94" fill="#9F1239" fill-opacity="0.65" />
+              <polygon points="50,50 94,50 50,94" fill="#9F1239" fill-opacity="0.48" />
+              <polygon points="50,6 94,50 50,94 6,50" fill="none" stroke="#9F1239" stroke-width="1.6" stroke-linejoin="round" />
+            </svg>
+            <div>
+              <div class="rubis-count">124 rubis</div>
+              <div class="rubis-sub">≈ <b>24 h 48</b> libérées ce mois</div>
+            </div>
+          </div>
+
+          <div class="kpis">
+            <div>
+              <div class="kpi-label">Encaissé</div>
+              <div class="kpi-value">14 320 €</div>
+              <div class="kpi-delta">+ 2 800 € vs avril</div>
+            </div>
+            <div>
+              <div class="kpi-label">DSO</div>
+              <div class="kpi-value">38 j</div>
+              <div class="kpi-delta">↘ −6 j depuis Rubis</div>
+            </div>
+          </div>
+
+          <div class="activity">
+            <span>✓ Facture <b>F-2024-035</b> encaissée</span>
+            <time>10:02</time>
+          </div>
+        </div>
+      </div>
+    </div>
+
+    <!-- Lib CDN pour export PNG -->
+    <script src="https://cdn.jsdelivr.net/npm/html-to-image@1.11.13/dist/html-to-image.min.js"></script>
+    <script>
+      const og = document.querySelector(".og");
+      const btnPng = document.getElementById("exportPng");
+
+      // Capture en 2× pour rendu net, puis le navigateur télécharge en 2400 × 1260
+      // (LinkedIn / Twitter / Facebook downsamplent au format final 1200 × 630).
+      const captureOptions = {
+        width: 1200,
+        height: 630,
+        canvasWidth: 1200 * 2,
+        canvasHeight: 630 * 2,
+        pixelRatio: 2,
+        backgroundColor: "#FAF7F2",
+        cacheBust: true,
+      };
+
+      btnPng.addEventListener("click", async () => {
+        btnPng.disabled = true;
+        btnPng.textContent = "⏳ Génération…";
+        try {
+          await document.fonts.ready;
+          const dataUrl = await htmlToImage.toPng(og, captureOptions);
+          const link = document.createElement("a");
+          link.download = "og-default.png";
+          link.href = dataUrl;
+          link.click();
+          btnPng.textContent = "✓ PNG téléchargé";
+          setTimeout(() => {
+            btnPng.textContent = "🖼️ Télécharger og-default.png";
+            btnPng.disabled = false;
+          }, 1800);
+        } catch (err) {
+          console.error("Export PNG :", err);
+          alert("Erreur export PNG : " + err.message);
+          btnPng.disabled = false;
+          btnPng.textContent = "🖼️ Télécharger og-default.png";
+        }
+      });
+    </script>
+  </body>
+</html>
