diff --git a/wwwroot/i18n/language.ui b/wwwroot/i18n/language.ui
new file mode 100644
index 0000000..065607e
--- /dev/null
+++ b/wwwroot/i18n/language.ui
@@ -0,0 +1,18 @@
+{
+    "widgettype": "Text",
+    "options": {
+        "css": "clickable",
+        "otext": "中",
+        "tip": "切换语言",
+        "i18n": false
+    },
+    "binds": [
+        {
+            "wid": "self",
+            "event": "app.lang",
+            "actiontype": "script",
+            "target": "self",
+            "script": "var L={'zh':'中','en':'EN','jp':'日','ko':'韩'};this.set_otext(L[bricks.app.lang]||'中')"
+        }
+    ]
+}
diff --git a/wwwroot/index.ui b/wwwroot/index.ui
index d4da3f9..32e436b 100644
--- a/wwwroot/index.ui
+++ b/wwwroot/index.ui
@@ -1,107 +1,132 @@
 {
+    "id": "app",
     "widgettype": "VBox",
     "options": {
-        "css": "rag-home",
-        "align": "center",
-        "padding": "20px"
+        "css": "filler",
+        "width": "100%",
+        "height": "100%",
+        "spacing": 0
     },
     "subwidgets": [
         {
-            "widgettype": "Text",
+            "widgettype": "urlwidget",
             "options": {
-                "text": "RAG Server — 多媒体知识库平台",
-                "css": "rag-title",
-                "i18n": false
-            }
-        },
-        {
-            "widgettype": "Text",
-            "options": {
-                "text": "支持文本、图片、音频、视频文件的智能检索与知识管理",
-                "css": "rag-subtitle",
-                "i18n": false
+                "url": "{{entire_url('/top.ui')}}"
             }
         },
         {
             "widgettype": "HBox",
             "options": {
-                "align": "center",
-                "gap": "16px",
-                "padding": "30px"
+                "css": "main-area",
+                "spacing": 0,
+                "width": "100%"
             },
             "subwidgets": [
                 {
-                    "widgettype": "Button",
+                    "widgettype": "VBox",
                     "options": {
-                        "label": "知识库管理",
-                        "bgcolor": "#4a90d9"
+                        "css": "rag-sidebar"
                     },
-                    "binds": [
+                    "subwidgets": [
                         {
-                            "wid": "self",
-                            "event": "tap",
-                            "actiontype": "urlwidget",
-                            "target": "app.rag_main",
-                            "mode": "replace",
+                            "widgettype": "Text",
                             "options": {
-                                "url": "{{entire_url('/knowledge_bases_list/index.ui')}}"
+                                "text": "RAG Server",
+                                "css": "menu-title"
                             }
+                        },
+                        {
+                            "widgettype": "Text",
+                            "options": {
+                                "text": "知识库",
+                                "css": "menu-item"
+                            },
+                            "binds": [
+                                {
+                                    "wid": "self",
+                                    "event": "click",
+                                    "actiontype": "urlwidget",
+                                    "target": "app.rag_main_content",
+                                    "mode": "replace",
+                                    "options": {
+                                        "url": "{{entire_url('/knowledge_bases_list/index.ui')}}"
+                                    }
+                                }
+                            ]
+                        },
+                        {
+                            "widgettype": "Text",
+                            "options": {
+                                "text": "文档管理",
+                                "css": "menu-item"
+                            },
+                            "binds": [
+                                {
+                                    "wid": "self",
+                                    "event": "click",
+                                    "actiontype": "urlwidget",
+                                    "target": "app.rag_main_content",
+                                    "mode": "replace",
+                                    "options": {
+                                        "url": "{{entire_url('/documents_list/index.ui')}}"
+                                    }
+                                }
+                            ]
+                        },
+                        {
+                            "widgettype": "Text",
+                            "options": {
+                                "text": "引擎配置",
+                                "css": "menu-item"
+                            },
+                            "binds": [
+                                {
+                                    "wid": "self",
+                                    "event": "click",
+                                    "actiontype": "urlwidget",
+                                    "target": "app.rag_main_content",
+                                    "mode": "replace",
+                                    "options": {
+                                        "url": "{{entire_url('/engine_configs_list/index.ui')}}"
+                                    }
+                                }
+                            ]
+                        },
+                        {
+                            "widgettype": "Text",
+                            "options": {
+                                "text": "订阅管理",
+                                "css": "menu-item"
+                            },
+                            "binds": [
+                                {
+                                    "wid": "self",
+                                    "event": "click",
+                                    "actiontype": "urlwidget",
+                                    "target": "app.rag_main_content",
+                                    "mode": "replace",
+                                    "options": {
+                                        "url": "{{entire_url('/subscriptions_list/index.ui')}}"
+                                    }
+                                }
+                            ]
                         }
                     ]
                 },
                 {
-                    "widgettype": "Button",
+                    "widgettype": "VBox",
                     "options": {
-                        "label": "文档管理",
-                        "bgcolor": "#50b86c"
+                        "id": "rag_main_content",
+                        "css": "rag-content",
+                        "padding": "0"
                     },
-                    "binds": [
+                    "subwidgets": [
                         {
-                            "wid": "self",
-                            "event": "tap",
-                            "actiontype": "urlwidget",
-                            "target": "app.rag_main",
-                            "mode": "replace",
+                            "widgettype": "Text",
                             "options": {
-                                "url": "{{entire_url('/documents_list/index.ui')}}"
-                            }
-                        }
-                    ]
-                },
-                {
-                    "widgettype": "Button",
-                    "options": {
-                        "label": "引擎配置",
-                        "bgcolor": "#e6a23c"
-                    },
-                    "binds": [
-                        {
-                            "wid": "self",
-                            "event": "tap",
-                            "actiontype": "urlwidget",
-                            "target": "app.rag_main",
-                            "mode": "replace",
-                            "options": {
-                                "url": "{{entire_url('/engine_configs_list/index.ui')}}"
-                            }
-                        }
-                    ]
-                },
-                {
-                    "widgettype": "Button",
-                    "options": {
-                        "label": "订阅管理",
-                        "bgcolor": "#f56c6c"
-                    },
-                    "binds": [
-                        {
-                            "wid": "self",
-                            "event": "tap",
-                            "actiontype": "urlwidget",
-                            "target": "app.rag_main",
-                            "mode": "replace",
-                            "options": {
-                                "url": "{{entire_url('/subscriptions_list/index.ui')}}"
+                                "text": "欢迎使用 RAG Server — 多媒体知识库平台",
+                                "css": "",
+                                "i18n": false
                             }
                         }
                     ]
@@ -109,12 +134,11 @@
             ]
         },
         {
-            "widgettype": "VBox",
+            "widgettype": "Text",
             "options": {
-                "id": "rag_main",
-                "padding": "20px"
-            },
-            "subwidgets": []
+                "text": "© 2026 RAG Server · 开元云科技",
+                "css": "rag-bottom"
+            }
         }
     ]
 }
diff --git a/wwwroot/shell_theme.css b/wwwroot/shell_theme.css
new file mode 100644
index 0000000..601510e
--- /dev/null
+++ b/wwwroot/shell_theme.css
@@ -0,0 +1,19 @@
+/* RAG Server Shell Theme */
+html, body { margin:0; padding:0; height:100%; overflow:hidden; }
+#app { display:flex; flex-direction:column; height:100vh; }
+
+/* Top bar */
+#top_panel { flex-shrink:0; }
+
+/* Center: menu + content */
+.main-area { flex:1; display:flex; overflow:hidden; }
+.rag-sidebar { width:200px; flex-shrink:0; background:#2c2c2c; color:#ccc; overflow-y:auto; }
+.rag-sidebar .menu-title { padding:12px 16px; font-size:13px; color:#888; text-transform:uppercase; border-bottom:1px solid #3a3a3a; }
+.rag-sidebar .menu-item { padding:10px 20px; cursor:pointer; font-size:14px; transition:background .2s; }
+.rag-sidebar .menu-item:hover { background:#3a3a3a; color:#fff; }
+
+/* Content */
+.rag-content { flex:1; overflow:auto; padding:0; }
+
+/* Bottom */
+.rag-bottom { flex-shrink:0; padding:8px 16px; text-align:center; font-size:12px; color:#888; background:#1a1a1a; border-top:1px solid #333; }
diff --git a/wwwroot/top.ui b/wwwroot/top.ui
new file mode 100644
index 0000000..57a98c8
--- /dev/null
+++ b/wwwroot/top.ui
@@ -0,0 +1,58 @@
+{
+    "id": "top_panel",
+    "widgettype": "HBox",
+    "options": {
+        "bgcolor": "#2c2c2c",
+        "cheight": 2.5,
+        "color": "#eeeeee",
+        "padding": "0 8px",
+        "align": "center",
+        "gap": "8px"
+    },
+    "subwidgets": [
+        {
+            "widgettype": "Svg",
+            "options": {
+                "rate": 2,
+                "url": "{{entire_url('/bricks/imgs/app.svg')}}",
+                "css": "clickable",
+                "tip": "RAG Server"
+            },
+            "binds": [
+                {
+                    "wid": "self",
+                    "event": "click",
+                    "actiontype": "script",
+                    "script": "bricks.app.show_windows_panel(event)"
+                }
+            ]
+        },
+        {
+            "widgettype": "Text",
+            "options": {
+                "text": "RAG Server",
+                "i18n": false,
+                "css": ""
+            }
+        },
+        {
+            "widgettype": "Text",
+            "options": {
+                "text": "",
+                "css": "filler"
+            }
+        },
+        {
+            "widgettype": "urlwidget",
+            "options": {
+                "url": "{{entire_url('/i18n/language.ui')}}"
+            }
+        },
+        {
+            "widgettype": "urlwidget",
+            "options": {
+                "url": "{{entire_url('/rbac/user/user_panel.ui')}}"
+            }
+        }
+    ]
+}