添加登录按钮

app/screens/ProfileScreen.tsx

@@ -293,6 +293,14 @@ export const ProfileScreen = () => {
               </View>
             </View>
           </ScrollView>
+
+          {/* Login Button at bottom of screen */}
+          <TouchableOpacity 
+            style={styles.fixedLoginButton} 
+            onPress={handleLogin}
+          >
+            <Text style={styles.loginButtonText}>{t("login.now")}</Text>
+          </TouchableOpacity>
         </View>
       </View>
     </SafeAreaView>
@@ -857,4 +865,18 @@ const styles = StyleSheet.create({
     fontSize: fontSize(16),
     fontWeight: "600",
   },
+  fixedLoginButton: {
+    backgroundColor: "#ff701e",
+    paddingHorizontal: 30,
+    paddingVertical: 10,
+    borderRadius: 20,
+    position: "absolute",
+    bottom: 20,
+    alignSelf: "center",
+    elevation: 5,
+    shadowColor: "#000",
+    shadowOffset: { width: 0, height: 2 },
+    shadowOpacity: 0.25,
+    shadowRadius: 3.84,
+  },
 });