style: restaure les couvertures (dégradés + vraie image si dispo)

templates/post_list.php

@@ -2,14 +2,24 @@
 require_once BASE_PATH . '/src/Parsedown.php';
 $Parsedown = new Parsedown();
 
+$coverGradients = [
+    'linear-gradient(135deg, #e0e7ff 0%, #c7d2fe 100%)',
+    'linear-gradient(135deg, #d1fae5 0%, #a7f3d0 100%)',
+    'linear-gradient(135deg, #fce7f3 0%, #fbcfe8 100%)',
+    'linear-gradient(135deg, #fef3c7 0%, #fde68a 100%)',
+    'linear-gradient(135deg, #dbeafe 0%, #bfdbfe 100%)',
+    'linear-gradient(135deg, #ede9fe 0%, #ddd6fe 100%)',
+];
+
 ob_start();
 ?>
 
 <div class="row row-cols-1 row-cols-md-2 row-cols-lg-3 g-4">
-<?php foreach ($posts as $post): ?>
+<?php foreach ($posts as $i => $post): ?>
     <?php
     $html            = $Parsedown->text($post['content']);
     $preview         = mb_strimwidth(strip_tags($html), 0, 120, '…');
+    $gradient        = $coverGradients[$i % count($coverGradients)];
     $postUrl         = '/post/' . rawurlencode($post['slug']);
     $isDraft         = !$post['published'];
     $isAvantPremiere = $post['published'] && strtotime((string)($post['published_at'] ?? '')) > time();
@@ -22,10 +32,13 @@ ob_start();
             <?php elseif ($isAvantPremiere): ?>
                 <div class="premiere-ribbon">Avant-première</div>
             <?php endif; ?>
-            <?php $coverFile = $post['cover'] ?? ''; ?>
-            <?php if ($coverFile !== ''): ?>
-                <div class="card-cover" style="background-image: url('/file?uuid=<?= rawurlencode($post['uuid']) ?>&name=<?= rawurlencode($coverFile) ?>')"></div>
-            <?php endif; ?>
+            <?php
+            $coverFile  = $post['cover'] ?? '';
+    $coverStyle = $coverFile !== ''
+        ? 'background-image: url(\'/file?uuid=' . rawurlencode($post['uuid']) . '&name=' . rawurlencode($coverFile) . '\')'
+        : 'background: ' . $gradient;
+    ?>
+            <div class="card-cover" style="<?= $coverStyle ?>"></div>
             <div class="card-body d-flex flex-column">
                 <h2 class="card-title">
                     <?php if ($isLocked): ?>