diff --git a/includes/class-html-exporter.php b/includes/class-html-exporter.php
index ffd8a86..df8fd78 100644
--- a/includes/class-html-exporter.php
+++ b/includes/class-html-exporter.php
@@ -200,7 +200,7 @@ body { margin: 0 !important; padding: 0 !important; }
                 <tr>
                     <td style="padding:0 40px 24px 40px;">
 
-                        <!-- Section heading with gradient underline -->
+                        <!-- Section heading with solid colour rule -->
                         <table role="presentation" border="0" cellpadding="0" cellspacing="0" width="100%">
                             <tr>
                                 <td style="padding-top:28px;padding-bottom:0;">
@@ -211,7 +211,13 @@ body { margin: 0 !important; padding: 0 !important; }
                             </tr>
                             <tr>
                                 <td style="padding-top:6px;padding-bottom:16px;">
-                                    <div style="height:3px;border-radius:2px;background:linear-gradient(to top, <?php echo esc_attr($block['color']); ?>, transparent);"></div>
+                                    <!-- Filet plein (pas de dégradé : non supporté par certains clients) -->
+                                    <table role="presentation" border="0" cellpadding="0" cellspacing="0" width="100%">
+                                        <tr>
+                                            <td height="3" bgcolor="<?php echo esc_attr($block['color']); ?>"
+                                                style="height:3px;line-height:3px;font-size:0;background-color:<?php echo esc_attr($block['color']); ?>;">&nbsp;</td>
+                                        </tr>
+                                    </table>
                                 </td>
                             </tr>
                         </table>
@@ -536,11 +542,14 @@ body { margin: 0 !important; padding: 0 !important; }
     private function format_date_for_category(int $post_id, int $cat_id): string {
         $window = Thalim_NL_Post_Query::get_window_type($cat_id);
 
+        // Ouvrages : année seule, comme l'affichage des cartes côté front.
+        $date_format = ($cat_id === THALIM_NL_CAT_OUVRAGES) ? 'Y' : 'j F Y';
+
         if ($window === 'debut_minus35_to_fin') {
             $raw_debut = get_post_meta($post_id, 'date_de_debut', true) ?: '';
             $raw_fin   = get_post_meta($post_id, 'date_de_fin',   true) ?: '';
-            $debut_str = $this->format_raw_date($raw_debut);
-            $fin_str   = $this->format_raw_date($raw_fin);
+            $debut_str = $this->format_raw_date($raw_debut, $date_format);
+            $fin_str   = $this->format_raw_date($raw_fin, $date_format);
             if ($debut_str && $fin_str && $debut_str !== $fin_str) {
                 return $debut_str . '–' . $fin_str;
             }
@@ -549,18 +558,18 @@ body { margin: 0 !important; padding: 0 !important; }
 
         $raw_dt = get_post_meta($post_id, 'datetime', true) ?: '';
         if ($raw_dt && !str_starts_with($raw_dt, '0000-00-00')) {
-            return $this->format_raw_date($raw_dt);
+            return $this->format_raw_date($raw_dt, $date_format);
         }
         $post = get_post($post_id);
-        return $post ? $this->format_raw_date($post->post_date) : '';
+        return $post ? $this->format_raw_date($post->post_date, $date_format) : '';
     }
 
-    private function format_raw_date(string $raw): string {
+    private function format_raw_date(string $raw, string $format = 'j F Y'): string {
         if (!$raw || str_starts_with($raw, '0000-00-00')) {
             return '';
         }
         $ts = strtotime($raw);
-        return $ts ? date_i18n('j F Y', $ts) : '';
+        return $ts ? date_i18n($format, $ts) : '';
     }
 
     // ── Rich-text processor (intro / conclusion) ──────────────────────────────