diff --git a/auth/forgot.php b/auth/forgot.php
index 2e543bb..4e808ef 100644
--- a/auth/forgot.php
+++ b/auth/forgot.php
@@ -57,6 +57,7 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
 
 // API for sending code
 if (isset($_GET['action']) && $_GET['action'] === 'send_code') {
+    ob_start();
     header('Content-Type: application/json');
     $account = $_GET['account'] ?? '';
     $type = $_GET['type'] ?? 'email';
@@ -66,6 +67,7 @@ if (isset($_GET['action']) && $_GET['action'] === 'send_code') {
     
     if ($type === 'email') {
         if (!filter_var($account, FILTER_VALIDATE_EMAIL)) {
+            ob_clean();
             echo json_encode(['success' => false, 'error' => __('invalid_email')]);
             exit;
         }
@@ -75,6 +77,7 @@ if (isset($_GET['action']) && $_GET['action'] === 'send_code') {
         $content = __('verification_code') . ": $code";
         $res = MailService::sendMail($account, $subject, $content, $content);
         if (!$res['success']) {
+            ob_clean();
             echo json_encode(['success' => false, 'error' => $res['error'] ?? __('send_failed')]);
             exit;
         }
@@ -83,6 +86,7 @@ if (isset($_GET['action']) && $_GET['action'] === 'send_code') {
         // SMS logic here if needed
     }
     
+    ob_clean();
     echo json_encode(['success' => true]);
     exit;
 }
@@ -241,13 +245,25 @@ function sendCode() {
     }
     
     const btn = document.getElementById('sendBtn');
+    const oldText = btn.innerText;
     btn.disabled = true;
     
     fetch('?action=send_code&account=' + encodeURIComponent(account) + '&type=' + type)
-        .then(res => res.json())
+        .then(res => {
+            if (!res.ok) throw new Error('Network error: ' + res.status);
+            return res.text().then(text => {
+                try {
+                    return JSON.parse(text);
+                } catch(e) {
+                    console.error('Raw response:', text);
+                    throw new Error('Invalid JSON response');
+                }
+            });
+        })
         .then(data => {
             if (data.success) {
                 let seconds = 60;
+                btn.innerText = seconds + 's';
                 const timer = setInterval(() => {
                     seconds--;
                     btn.innerText = seconds + 's';
@@ -260,7 +276,14 @@ function sendCode() {
             } else {
                 alert(data.error || '<?= __('send_failed') ?>');
                 btn.disabled = false;
+                btn.innerText = oldText;
             }
+        })
+        .catch(err => {
+            console.error(err);
+            alert('Error: ' + err.message);
+            btn.disabled = false;
+            btn.innerText = oldText;
         });
 }
 </script>
diff --git a/auth/register.php b/auth/register.php
index c950869..56a9162 100644
--- a/auth/register.php
+++ b/auth/register.php
@@ -80,12 +80,14 @@ if ($_SERVER['REQUEST_METHOD'] === 'POST') {
 
 // Add API for sending verification code
 if (isset($_GET['action']) && $_GET['action'] === 'send_code') {
+    ob_start();
     header('Content-Type: application/json');
     $account = $_GET['account'] ?? '';
     $type = $_GET['type'] ?? 'email';
     
     if ($type === 'email') {
         if (!filter_var($account, FILTER_VALIDATE_EMAIL)) {
+            ob_clean();
             echo json_encode(['success' => false, 'error' => __('invalid_email')]);
             exit;
         }
@@ -102,6 +104,7 @@ if (isset($_GET['action']) && $_GET['action'] === 'send_code') {
         $res = MailService::sendMail($account, $subject, $content, $content);
         
         if (!$res['success']) {
+            ob_clean();
             echo json_encode(['success' => false, 'error' => $res['error'] ?? __('send_failed')]);
             exit;
         }
@@ -111,6 +114,7 @@ if (isset($_GET['action']) && $_GET['action'] === 'send_code') {
         // For now, we just store it in session.
     }
     
+    ob_clean();
     echo json_encode(['success' => true]);
     exit;
 }
@@ -296,13 +300,25 @@ function sendCode() {
     }
     
     const btn = document.getElementById('sendBtn');
+    const oldText = btn.innerText;
     btn.disabled = true;
     
     fetch('?action=send_code&account=' + encodeURIComponent(account) + '&type=' + type)
-        .then(res => res.json())
+        .then(res => {
+            if (!res.ok) throw new Error('Network error: ' + res.status);
+            return res.text().then(text => {
+                try {
+                    return JSON.parse(text);
+                } catch(e) {
+                    console.error('Raw response:', text);
+                    throw new Error('Invalid JSON response');
+                }
+            });
+        })
         .then(data => {
             if (data.success) {
                 let seconds = 60;
+                btn.innerText = seconds + 's';
                 const timer = setInterval(() => {
                     seconds--;
                     btn.innerText = seconds + 's';
@@ -315,7 +331,14 @@ function sendCode() {
             } else {
                 alert(data.error || '<?= __('send_failed') ?>');
                 btn.disabled = false;
+                btn.innerText = oldText;
             }
+        })
+        .catch(err => {
+            console.error(err);
+            alert('Error: ' + err.message);
+            btn.disabled = false;
+            btn.innerText = oldText;
         });
 }
 </script>