视觉与UX体验升级：全站配图全面采用现代中式科技高级抽象矢量体系并补充技术文章智能封面Fallback

addons/official/view/web/official_home/index.html

@@ -852,7 +852,16 @@
                     {if !empty($art['image'])}
                     <img src="{$art['image']}" alt="{$art['title']}" loading="lazy">
                     {else/}
-                    <div style="width: 100%; height: 100%; display: flex; align-items: center; justify-content: center; background: #F1F5F9; color: #94A3B8; font-size: 14px;">纳海川技术洞察</div>
+                    {php}
+                        $cover_fallbacks = [
+                            0 => '/assets/addons/official/images/articles/article_cache.svg',
+                            1 => '/assets/addons/official/images/articles/article_mysql_page.svg',
+                            2 => '/assets/addons/official/images/articles/article_xxl_job.svg',
+                            3 => '/assets/addons/official/images/articles/article_redis_split.svg',
+                        ];
+                        $cover_src = isset($cover_fallbacks[$idx]) ? $cover_fallbacks[$idx] : '/assets/addons/official/images/articles/article_microservice.svg';
+                    {/php}
+                    <img src="{$cover_src}" alt="{$art['title']}" loading="lazy" style="width: 100%; height: 100%; object-fit: cover;">
                     {/if}
                 </a>
                 <div class="nhc-article-card-body">