feat: 更新主题配置与系统设置

frontend-web/src/components/page-sdebar.css

@@ -607,6 +607,27 @@ html.lightyellow .light-topnav-item--active::after {
 }
 
 /* ── 侧边栏：二级图标卡片列（96px）+ 右侧三级列（展开时整体变宽，带过渡）──────── */
+/* Runtime themes use their configurable header gradient rather than the
+   red/blue banner artwork. Navigation copy follows an automatically chosen
+   contrasting foreground so both pale and deep brand colours remain legible. */
+html[data-custom-theme="true"] .light-topnav-item,
+html[data-custom-theme="true"] .top-submenu-item {
+    color: var(--navigation-foreground);
+}
+
+html[data-custom-theme="true"] .light-topnav-item:hover,
+html[data-custom-theme="true"] .light-topnav-item--active,
+html[data-custom-theme="true"] .light-topnav-item--active:hover,
+html[data-custom-theme="true"] .top-submenu-item:hover,
+html[data-custom-theme="true"] .top-submenu-item--active {
+    color: var(--navigation-foreground);
+    text-shadow: none;
+}
+
+html[data-custom-theme="true"] .light-topnav-item--active::after {
+    background: var(--navigation-foreground);
+}
+
 .light-sidebar {
     position: fixed;
     left: 0;