feat(frontend): align single related/prevnext/maxheight with Zibll

Honor prevnext/authordesc/yiyan settings, multi-tax related queries with
orderby (incl. views), per-post maxheight override, and only expand content
when maxheight is enabled.

assets/css/frontend/single-post/related-toc.css

@@ -434,3 +434,41 @@ html.dark .article-end-separator span {
     }
 }
 
+
+
+/* ===== Related list (Zibll-like) ===== */
+.relates .title-theme,
+.related-box .title-theme {
+    font-size: 14px;
+    font-weight: 700;
+    margin: 0 0 8px;
+}
+.related-list,
+.relates ul.no-thumb {
+    list-style: none;
+    margin: 0;
+    padding: 4px 0 8px;
+}
+.related-list li,
+.relates ul.no-thumb li {
+    padding: 8px 0;
+    border-bottom: 1px solid var(--color-line);
+}
+.related-list li:last-child,
+.relates ul.no-thumb li:last-child {
+    border-bottom: none;
+}
+.related-list a,
+.relates ul.no-thumb a {
+    color: var(--color-ink);
+    text-decoration: none;
+    font-size: 14px;
+}
+.related-list a:hover,
+.relates ul.no-thumb a:hover {
+    color: var(--color-primary);
+}
+.post-nav-box.is-empty,
+.post-nav-box__item.is-empty {
+    visibility: hidden;
+}