diff --git a/lite/proxy_lite.py b/lite/proxy_lite.py
index 6e30ca4..3cb3737 100644
--- a/lite/proxy_lite.py
+++ b/lite/proxy_lite.py
@@ -1123,7 +1123,7 @@ class LoginDialog(QDialog):
         super().__init__(parent)
         self.setWindowTitle("节点配置登录")
         self.setWindowIcon(load_icon())
-        self.setFixedSize(340, 190)
+        self.setFixedSize(380, 200)
         self.setStyleSheet(f"""
             QDialog {{ background-color: {C_BG}; }}
             QLabel {{ color: {C_TEXT}; font-family: "Microsoft YaHei", "Segoe UI", sans-serif; font-size: 12px; }}
@@ -1137,15 +1137,15 @@ class LoginDialog(QDialog):
             }}
             QPushButton#btnOk {{
                 background-color: {C_GREEN}; color: #fff; border: none;
-                border-radius: 6px; padding: 7px 18px;
-                font-size: 13px; font-weight: bold;
+                border-radius: 6px; padding: 4px 12px;
+                font-size: 12px; font-weight: bold;
             }}
             QPushButton#btnOk:hover {{ background-color: #5ed978; }}
             QPushButton#btnOk:disabled {{ background-color: #2a3a2e; color: #666; }}
             QPushButton#btnCancel {{
                 background-color: {C_CARD}; color: {C_SUBTEXT};
                 border: 1px solid {C_BORDER}; border-radius: 6px;
-                padding: 7px 18px; font-size: 13px;
+                padding: 4px 12px; font-size: 12px;
             }}
         """)
 
@@ -1155,8 +1155,8 @@ class LoginDialog(QDialog):
 
         # 左侧 logo
         logo = QLabel()
-        logo.setPixmap(load_icon().pixmap(48, 48))
-        logo.setFixedSize(48, 48)
+        logo.setPixmap(load_icon().pixmap(64, 64))
+        logo.setFixedSize(64, 64)
         logo.setAlignment(Qt.AlignCenter)
         root.addWidget(logo, 0, Qt.AlignVCenter)
 
@@ -1175,6 +1175,8 @@ class LoginDialog(QDialog):
 
         self.lb_err = QLabel("")
         self.lb_err.setStyleSheet(f"color: {C_RED}; font-size: 11px;")
+        self.lb_err.setFixedHeight(14)
+        self.lb_err.hide()  # 无错误时不占空间，避免密码框下方留大片空白
         form.addWidget(self.lb_err)
 
         bottom = QHBoxLayout()
@@ -1201,10 +1203,12 @@ class LoginDialog(QDialog):
         password = self.ed_pass.text()
         if not user or not password:
             self.lb_err.setText("请输入用户名和密码")
+            self.lb_err.show()
             return
         self.btn_ok.setEnabled(False)
         self.btn_cancel.setEnabled(False)
         self.lb_err.setText("正在登录...")
+        self.lb_err.show()
         threading.Thread(target=self._worker, args=(user, password), daemon=True).start()
 
     def _worker(self, user, password):
@@ -1236,6 +1240,7 @@ class LoginDialog(QDialog):
             self.accept()
         else:
             self.lb_err.setText(info)
+            self.lb_err.show()
 
 # ── 状态指示灯（小圆点） ───────────────────────────────
 
@@ -1596,9 +1601,14 @@ class MainWindow(QWidget):
 
     # ── 节点登录 ──
     def _maybe_show_login(self):
-        """启动时节点未配置则弹出登录框。"""
+        """启动时节点未配置：隐藏主窗口只显示登录框；登录成功恢复，取消则退出。"""
         if _endpoint_domain() == "???":
+            self.hide()
             self._show_login_dialog()
+            if _endpoint_domain() == "???":
+                self.quit_app()  # 未登录且无可用节点，直接退出
+                return
+            self.show()
 
     def _show_login_dialog(self):
         """弹出登录框；成功后重载节点并刷新标题。"""