diff --git a/app/src/main/java/com/android/trisolarispms/ui/auth/AuthScreen.kt b/app/src/main/java/com/android/trisolarispms/ui/auth/AuthScreen.kt
index 5a2ead2..a60e67c 100644
--- a/app/src/main/java/com/android/trisolarispms/ui/auth/AuthScreen.kt
+++ b/app/src/main/java/com/android/trisolarispms/ui/auth/AuthScreen.kt
@@ -1,6 +1,9 @@
 package com.android.trisolarispms.ui.auth
 
 import androidx.activity.ComponentActivity
+import android.content.Context
+import android.net.ConnectivityManager
+import android.net.NetworkCapabilities
 import androidx.compose.foundation.layout.Arrangement
 import androidx.compose.foundation.layout.Column
 import androidx.compose.foundation.layout.Spacer
@@ -48,6 +51,10 @@ fun AuthScreen(viewModel: AuthViewModel = viewModel()) {
     val phoneCountries = remember { phoneCountryOptions() }
     val phoneCountrySearch = remember { mutableStateOf("") }
     val now = remember { mutableStateOf(System.currentTimeMillis()) }
+    val hasNetwork = remember(context, state.error) { hasInternetConnection(context) }
+    val noNetworkError = state.error?.contains("No internet connection", ignoreCase = true) == true
+    val isCheckingExistingSession = state.isLoading && !state.apiVerified && state.userId != null
+    val shouldHideAuthForm = !hasNetwork || noNetworkError || isCheckingExistingSession
 
     LaunchedEffect(state.resendAvailableAt) {
         while (state.resendAvailableAt != null) {
@@ -56,6 +63,30 @@ fun AuthScreen(viewModel: AuthViewModel = viewModel()) {
         }
     }
 
+    if (shouldHideAuthForm) {
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(24.dp),
+            verticalArrangement = Arrangement.Center
+        ) {
+            if (isCheckingExistingSession) {
+                Text(text = "Checking session...", style = MaterialTheme.typography.headlineSmall)
+                Spacer(modifier = Modifier.height(8.dp))
+                CircularProgressIndicator()
+            } else {
+                Text(text = "No internet connection", style = MaterialTheme.typography.headlineSmall)
+                Spacer(modifier = Modifier.height(8.dp))
+                Text(text = "Please connect to the internet and try again.")
+            }
+            Spacer(modifier = Modifier.height(16.dp))
+            Button(onClick = viewModel::retryAfterConnectivityIssue) {
+                Text("Retry")
+            }
+        }
+        return
+    }
+
     Column(
         modifier = Modifier
             .fillMaxSize()
@@ -200,12 +231,6 @@ fun AuthScreen(viewModel: AuthViewModel = viewModel()) {
             }
         }
 
-        if (state.userId != null) {
-            Spacer(modifier = Modifier.height(8.dp))
-            Text(text = "Firebase user: ${state.userId}")
-            Text(text = "API verified: ${state.apiVerified}")
-        }
-
         if (state.noProperties) {
             Spacer(modifier = Modifier.height(12.dp))
             Text(
@@ -215,3 +240,10 @@ fun AuthScreen(viewModel: AuthViewModel = viewModel()) {
         }
     }
 }
+
+private fun hasInternetConnection(context: Context): Boolean {
+    val cm = context.getSystemService(Context.CONNECTIVITY_SERVICE) as? ConnectivityManager ?: return false
+    val network = cm.activeNetwork ?: return false
+    val capabilities = cm.getNetworkCapabilities(network) ?: return false
+    return capabilities.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
+}
diff --git a/app/src/main/java/com/android/trisolarispms/ui/auth/AuthViewModel.kt b/app/src/main/java/com/android/trisolarispms/ui/auth/AuthViewModel.kt
index 41f4d78..bf73a1f 100644
--- a/app/src/main/java/com/android/trisolarispms/ui/auth/AuthViewModel.kt
+++ b/app/src/main/java/com/android/trisolarispms/ui/auth/AuthViewModel.kt
@@ -18,6 +18,7 @@ import kotlinx.coroutines.launch
 import kotlinx.coroutines.tasks.await
 import kotlinx.coroutines.Job
 import kotlinx.coroutines.delay
+import java.net.UnknownHostException
 import java.util.concurrent.TimeUnit
 
 class AuthViewModel(
@@ -68,6 +69,15 @@ class AuthViewModel(
         _state.update { it.copy(error = null) }
     }
 
+    fun retryAfterConnectivityIssue() {
+        val currentUser = auth.currentUser
+        if (currentUser != null) {
+            verifyExistingSession(currentUser.uid)
+        } else {
+            clearError()
+        }
+    }
+
     fun reportError(message: String) {
         setError(message)
     }
@@ -96,7 +106,7 @@ class AuthViewModel(
             }
 
             override fun onVerificationFailed(e: FirebaseException) {
-                setError(e.localizedMessage ?: "Verification failed")
+                setError(mapThrowableToMessage(e, fallback = "Verification failed"))
             }
 
             override fun onCodeSent(
@@ -168,7 +178,7 @@ class AuthViewModel(
                 val response = api.verifyAuth()
                 handleVerifyResponse(userId, response)
             } catch (e: Exception) {
-                setError(e.localizedMessage ?: "Sign-in failed")
+                setError(mapThrowableToMessage(e, fallback = "Sign-in failed"))
             }
         }
     }
@@ -200,7 +210,7 @@ class AuthViewModel(
                 val response = api.verifyAuth()
                 handleVerifyResponse(userId, response)
             } catch (e: Exception) {
-                setError(e.localizedMessage ?: "Session verify failed")
+                setError(mapThrowableToMessage(e, fallback = "Session verify failed"))
             }
         }
     }
@@ -251,7 +261,7 @@ class AuthViewModel(
                         noProperties = false,
                         unauthorized = false,
                         propertyRoles = emptyMap(),
-                        error = "API verify failed: ${response.code()}"
+                        error = mapHttpError(response.code(), "API verify failed")
                     )
                 }
             }
@@ -309,10 +319,10 @@ class AuthViewModel(
                         )
                     }
                 } else {
-                    setError("Update failed: ${response.code()}")
+                    setError(mapHttpError(response.code(), "Update failed"))
                 }
             } catch (e: Exception) {
-                setError(e.localizedMessage ?: "Update failed")
+                setError(mapThrowableToMessage(e, fallback = "Update failed"))
             }
         }
     }
@@ -336,4 +346,21 @@ class AuthViewModel(
             }
         }
     }
+
+    private fun mapHttpError(code: Int, prefix: String): String {
+        return if (code >= 500) {
+            "Server down. Please try again."
+        } else {
+            "$prefix: $code"
+        }
+    }
+
+    private fun mapThrowableToMessage(throwable: Throwable, fallback: String): String {
+        return when {
+            throwable is UnknownHostException -> "No internet connection."
+            throwable.localizedMessage?.contains("Unable to resolve host", ignoreCase = true) == true ->
+                "No internet connection."
+            else -> throwable.localizedMessage ?: fallback
+        }
+    }
 }