diff --git a/canfd_settings.h b/canfd_settings.h
new file mode 100644
index 0000000..986280b
--- /dev/null
+++ b/canfd_settings.h
@@ -0,0 +1,550 @@
+#ifndef CANFD_SETTINGS_H
+#define CANFD_SETTINGS_H
+
+const char canfd_settings_html[] PROGMEM = R"rawliteral(
+<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="UTF-8">
+    <meta name="viewport" content="width=device-width, initial-scale=1.0">
+    <title>Settings - ESP32-S3 CAN FD Logger</title>
+    <style>
+        * { margin: 0; padding: 0; box-sizing: border-box; }
+        body {
+            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
+            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+            min-height: 100vh;
+            padding: 10px;
+        }
+        .container {
+            max-width: 800px;
+            margin: 0 auto;
+            background: white;
+            border-radius: 15px;
+            box-shadow: 0 20px 60px rgba(0,0,0,0.3);
+            overflow: hidden;
+        }
+        .header {
+            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+            color: white;
+            padding: 20px;
+            text-align: center;
+        }
+        .header h1 { font-size: 28px; margin-bottom: 5px; }
+        .header p { opacity: 0.9; font-size: 14px; }
+        
+        /* Navigation */
+        .nav {
+            background: #f8f9fa;
+            padding: 0;
+            border-bottom: 2px solid #e0e0e0;
+            display: flex;
+            flex-wrap: wrap;
+            justify-content: center;
+        }
+        .nav a {
+            padding: 15px 20px;
+            text-decoration: none;
+            color: #666;
+            font-weight: 500;
+            font-size: 14px;
+            border-bottom: 3px solid transparent;
+            transition: all 0.3s;
+        }
+        .nav a:hover {
+            background: #e9ecef;
+            color: #667eea;
+        }
+        .nav a.active {
+            color: #764ba2;
+            border-bottom-color: #764ba2;
+            background: white;
+            font-weight: 600;
+        }
+        
+        .content { padding: 30px; }
+        
+        .settings-section {
+            background: #f8f9fa;
+            padding: 25px;
+            border-radius: 10px;
+            margin-bottom: 20px;
+            box-shadow: 0 2px 8px rgba(0,0,0,0.05);
+        }
+        
+        .section-title {
+            color: #333;
+            font-size: 20px;
+            margin-bottom: 20px;
+            padding-bottom: 10px;
+            border-bottom: 3px solid #667eea;
+            display: flex;
+            align-items: center;
+            gap: 10px;
+        }
+        
+        .form-group {
+            margin-bottom: 20px;
+        }
+        
+        label {
+            display: block;
+            font-weight: 600;
+            color: #333;
+            margin-bottom: 8px;
+            font-size: 14px;
+        }
+        
+        .help-text {
+            font-size: 12px;
+            color: #666;
+            margin-top: 5px;
+            line-height: 1.4;
+        }
+        
+        input[type="text"],
+        input[type="password"],
+        select {
+            width: 100%;
+            padding: 12px 15px;
+            border: 2px solid #e1e8ed;
+            border-radius: 8px;
+            font-size: 14px;
+            transition: all 0.3s;
+            background: white;
+        }
+        
+        input:focus, select:focus {
+            outline: none;
+            border-color: #667eea;
+            box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
+        }
+        
+        input[type="checkbox"] {
+            width: 20px;
+            height: 20px;
+            cursor: pointer;
+            margin-right: 10px;
+        }
+        
+        .checkbox-group {
+            display: flex;
+            align-items: center;
+            margin-bottom: 15px;
+        }
+        
+        .checkbox-group label {
+            margin-bottom: 0;
+            cursor: pointer;
+        }
+        
+        .sta-settings {
+            background: #f0f4f8;
+            padding: 20px;
+            border-radius: 8px;
+            margin-top: 15px;
+            border-left: 4px solid #667eea;
+        }
+        
+        .sta-settings.disabled {
+            opacity: 0.5;
+            pointer-events: none;
+        }
+        
+        .button-group {
+            display: flex;
+            gap: 15px;
+            margin-top: 30px;
+            flex-wrap: wrap;
+        }
+        
+        button {
+            flex: 1;
+            min-width: 150px;
+            padding: 14px 28px;
+            border: none;
+            border-radius: 8px;
+            font-size: 14px;
+            font-weight: 700;
+            cursor: pointer;
+            transition: all 0.3s;
+            text-transform: uppercase;
+        }
+        
+        .btn-save {
+            background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
+            color: white;
+            box-shadow: 0 4px 15px rgba(17, 153, 142, 0.3);
+        }
+        
+        .btn-save:hover {
+            transform: translateY(-2px);
+            box-shadow: 0 6px 20px rgba(17, 153, 142, 0.4);
+        }
+        
+        .btn-cancel {
+            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+            color: white;
+            box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
+        }
+        
+        .btn-cancel:hover {
+            transform: translateY(-2px);
+            box-shadow: 0 6px 20px rgba(102, 126, 234, 0.4);
+        }
+        
+        .alert {
+            padding: 15px 20px;
+            border-radius: 8px;
+            margin-bottom: 20px;
+            display: none;
+            align-items: center;
+            gap: 12px;
+        }
+        
+        .alert.show {
+            display: flex;
+        }
+        
+        .alert-success {
+            background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
+            color: white;
+        }
+        
+        .alert-info {
+            background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
+            color: white;
+        }
+        
+        .alert-icon {
+            font-size: 20px;
+        }
+        
+        .alert-text {
+            flex: 1;
+            font-weight: 600;
+        }
+        
+        .info-box {
+            background: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);
+            border-left: 4px solid #667eea;
+            padding: 15px 20px;
+            border-radius: 8px;
+            margin-top: 15px;
+        }
+        
+        .info-box-title {
+            font-weight: 700;
+            color: #333;
+            margin-bottom: 8px;
+        }
+        
+        .info-box-text {
+            color: #555;
+            font-size: 13px;
+            line-height: 1.6;
+        }
+        
+        .sta-status {
+            margin-top: 15px;
+            padding: 12px;
+            background: #e8f5e9;
+            border-radius: 6px;
+            color: #2e7d32;
+            font-weight: 600;
+            display: none;
+        }
+    </style>
+</head>
+<body>
+    <div class="container">
+        <div class="header">
+            <h1>⚙️ Settings</h1>
+            <p>Configure WiFi and CAN Settings</p>
+        </div>
+
+        <div class="nav">
+            <a href="/">📊 Dashboard</a>
+            <a href="/settings" class="active">⚙️ Settings</a>
+            <a href="/graph">📈 Graph</a>
+        </div>
+
+        <div class="content">
+            <div id="alert-success" class="alert alert-success">
+                <span class="alert-icon">✓</span>
+                <span class="alert-text">Settings saved successfully!</span>
+            </div>
+            
+            <div id="alert-loading" class="alert alert-info">
+                <span class="alert-icon">⏳</span>
+                <span class="alert-text">Loading settings...</span>
+            </div>
+            
+            <!-- WiFi Settings -->
+            <div class="settings-section">
+                <div class="section-title">
+                    <span>📶</span>
+                    <span>WiFi Configuration</span>
+                </div>
+                
+                <h3 style="color: #333; font-size: 16px; margin-bottom: 15px;">AP Mode (Access Point)</h3>
+                
+                <div class="form-group">
+                    <label for="wifi-ssid">AP SSID (네트워크 이름)</label>
+                    <input type="text" id="wifi-ssid" placeholder="Byun_CANFD_Logger" maxlength="31">
+                    <div class="help-text">ESP32가 생성할 WiFi 네트워크 이름 (최대 31자)</div>
+                </div>
+                
+                <div class="form-group">
+                    <label for="wifi-password">AP Password (비밀번호)</label>
+                    <input type="password" id="wifi-password" placeholder="최소 8자 이상" minlength="8" maxlength="63">
+                    <div class="help-text">WiFi 접속 시 필요한 비밀번호 (8-63자)</div>
+                </div>
+                
+                <hr style="margin: 25px 0; border: none; border-top: 1px solid #ddd;">
+                
+                <h3 style="color: #333; font-size: 16px; margin-bottom: 15px;">APSTA Mode (AP + Station)</h3>
+                
+                <div class="checkbox-group">
+                    <input type="checkbox" id="sta-enable" onchange="toggleSTASettings()">
+                    <label for="sta-enable">Station 모드 활성화 (외부 WiFi에 연결)</label>
+                </div>
+                <div class="help-text" style="margin-left: 30px; margin-bottom: 15px;">
+                    AP와 Station을 동시에 사용하여 인터넷 접속 가능
+                </div>
+                
+                <div id="sta-settings" class="sta-settings disabled">
+                    <div class="form-group">
+                        <label for="sta-ssid">연결할 WiFi SSID</label>
+                        <input type="text" id="sta-ssid" placeholder="공유기 이름 입력" maxlength="31">
+                        <div class="help-text">연결할 외부 WiFi 네트워크 이름</div>
+                    </div>
+                    
+                    <div class="form-group">
+                        <label for="sta-password">연결할 WiFi Password</label>
+                        <input type="password" id="sta-password" placeholder="공유기 비밀번호 입력" maxlength="63">
+                        <div class="help-text">외부 WiFi 비밀번호</div>
+                    </div>
+                    
+                    <div id="sta-status" class="sta-status">
+                        ✓ WiFi 연결됨: <span id="sta-ip"></span>
+                    </div>
+                </div>
+            </div>
+            
+            <!-- CAN Settings -->
+            <div class="settings-section">
+                <div class="section-title">
+                    <span>🚗</span>
+                    <span>CAN Configuration</span>
+                </div>
+                
+                <div class="form-group">
+                    <label for="can-mode">CAN Mode</label>
+                    <select id="can-mode" onchange="toggleDataRate()">
+                        <option value="fd">CAN FD Mode</option>
+                        <option value="classic">Classic CAN Mode</option>
+                    </select>
+                    <div class="help-text">CAN FD: 최대 64바이트, Classic CAN: 최대 8바이트</div>
+                </div>
+                
+                <div class="form-group">
+                    <label for="bit-rate">Arbitration Bit Rate</label>
+                    <select id="bit-rate">
+                        <option value="125000">125 kbps</option>
+                        <option value="250000">250 kbps</option>
+                        <option value="500000" selected>500 kbps</option>
+                        <option value="1000000">1 Mbps</option>
+                    </select>
+                    <div class="help-text">CAN 버스 속도</div>
+                </div>
+                
+                <div class="form-group" id="data-rate-group">
+                    <label for="data-rate">Data Rate Factor (CAN FD만)</label>
+                    <select id="data-rate">
+                        <option value="1">x1</option>
+                        <option value="2">x2</option>
+                        <option value="4" selected>x4 (권장)</option>
+                        <option value="8">x8</option>
+                    </select>
+                    <div class="help-text">CAN FD 데이터 구간 속도 배율</div>
+                </div>
+                
+                <div class="form-group">
+                    <label for="controller-mode">Controller Mode</label>
+                    <select id="controller-mode">
+                        <option value="0" selected>Normal</option>
+                        <option value="1">Listen Only</option>
+                        <option value="2">Loopback</option>
+                    </select>
+                    <div class="help-text">Normal: 일반 통신, Listen Only: 수신 전용</div>
+                </div>
+            </div>
+            
+            <div class="button-group">
+                <button class="btn-save" onclick="saveSettings()">💾 Save Settings</button>
+                <button class="btn-cancel" onclick="location.href='/'">← Back to Dashboard</button>
+            </div>
+            
+            <div class="info-box">
+                <div class="info-box-title">
+                    ⚠️ 중요 안내
+                </div>
+                <div class="info-box-text">
+                    • WiFi 설정을 변경한 경우, <strong>ESP32를 재부팅</strong>해야 새 SSID/비밀번호가 적용됩니다.<br>
+                    • <strong>APSTA 모드:</strong> Station 모드를 활성화하면 ESP32가 AP와 Station을 동시에 사용합니다.<br>
+                    • Station 모드로 외부 WiFi에 연결하면 인터넷 접속이 가능해집니다.<br>
+                    • Station 연결 실패 시에도 AP 모드는 정상 동작합니다.<br>
+                    • CAN 설정 변경 후에도 <strong>ESP32 재부팅</strong>이 필요합니다.<br>
+                    • 설정 저장 후 ESP32의 <strong>RST 버튼</strong>을 눌러 재부팅하세요.
+                </div>
+            </div>
+        </div>
+    </div>
+
+    <script>
+        function loadSettings() {
+            fetch('/settings/get')
+                .then(r => r.json())
+                .then(data => {
+                    // WiFi settings
+                    document.getElementById('wifi-ssid').value = data.wifiSSID || 'Byun_CANFD_Logger';
+                    document.getElementById('wifi-password').value = data.wifiPassword || '';
+                    
+                    // STA settings
+                    document.getElementById('sta-enable').checked = data.staEnable || false;
+                    document.getElementById('sta-ssid').value = data.staSSID || '';
+                    document.getElementById('sta-password').value = data.staPassword || '';
+                    
+                    // CAN settings
+                    document.getElementById('can-mode').value = data.canMode || 'fd';
+                    document.getElementById('bit-rate').value = data.bitRate || 500000;
+                    document.getElementById('data-rate').value = data.dataRate || 4;
+                    document.getElementById('controller-mode').value = data.controllerMode || 0;
+                    
+                    // Update UI
+                    toggleSTASettings();
+                    toggleDataRate();
+                    
+                    // STA status
+                    if (data.staConnected && data.staIP && data.staIP !== '0.0.0.0') {
+                        document.getElementById('sta-ip').textContent = data.staIP;
+                        document.getElementById('sta-status').style.display = 'block';
+                    } else {
+                        document.getElementById('sta-status').style.display = 'none';
+                    }
+                    
+                    hideAlert('alert-loading');
+                })
+                .catch(err => {
+                    console.error('Failed to load settings:', err);
+                    hideAlert('alert-loading');
+                });
+        }
+
+        function saveSettings() {
+            const settings = {
+                wifiSSID: document.getElementById('wifi-ssid').value.trim(),
+                wifiPassword: document.getElementById('wifi-password').value,
+                staEnable: document.getElementById('sta-enable').checked,
+                staSSID: document.getElementById('sta-ssid').value.trim(),
+                staPassword: document.getElementById('sta-password').value,
+                canMode: document.getElementById('can-mode').value,
+                bitRate: parseInt(document.getElementById('bit-rate').value),
+                dataRate: parseInt(document.getElementById('data-rate').value),
+                controllerMode: parseInt(document.getElementById('controller-mode').value)
+            };
+
+            // Validation
+            if (settings.wifiSSID.length === 0) {
+                alert('WiFi SSID를 입력하세요.');
+                return;
+            }
+            
+            if (settings.wifiPassword.length > 0 && settings.wifiPassword.length < 8) {
+                alert('WiFi 비밀번호는 최소 8자 이상이어야 합니다.');
+                return;
+            }
+            
+            if (settings.staEnable && settings.staSSID.length === 0) {
+                alert('Station 모드를 활성화하려면 WiFi SSID를 입력하세요.');
+                return;
+            }
+
+            fetch('/settings/save', {
+                method: 'POST',
+                headers: {'Content-Type': 'application/json'},
+                body: JSON.stringify(settings)
+            })
+            .then(r => r.json())
+            .then(data => {
+                if (data.success) {
+                    showAlert('alert-success', '설정이 저장되었습니다! ESP32를 재부팅하세요.', 'alert-success');
+                } else {
+                    alert('설정 저장 실패: ' + data.message);
+                }
+            })
+            .catch(err => {
+                alert('설정 저장 실패: ' + err);
+            });
+        }
+
+        function toggleSTASettings() {
+            const staEnable = document.getElementById('sta-enable').checked;
+            const staSettings = document.getElementById('sta-settings');
+            
+            if (staEnable) {
+                staSettings.classList.remove('disabled');
+            } else {
+                staSettings.classList.add('disabled');
+            }
+        }
+        
+        function toggleDataRate() {
+            const canMode = document.getElementById('can-mode').value;
+            const dataRateGroup = document.getElementById('data-rate-group');
+            
+            if (canMode === 'classic') {
+                dataRateGroup.style.display = 'none';
+            } else {
+                dataRateGroup.style.display = 'block';
+            }
+        }
+
+        function showAlert(alertId, message, className) {
+            const alert = document.getElementById(alertId);
+            if (alert) {
+                const textElement = alert.querySelector('.alert-text');
+                if (textElement && message) {
+                    textElement.textContent = message;
+                }
+                
+                alert.className = 'alert ' + className;
+                alert.classList.add('show');
+                
+                if (className === 'alert-success') {
+                    setTimeout(() => {
+                        hideAlert(alertId);
+                    }, 5000);
+                }
+            }
+        }
+
+        function hideAlert(alertId) {
+            const alert = document.getElementById(alertId);
+            if (alert) {
+                alert.classList.remove('show');
+            }
+        }
+
+        // Load settings on page load
+        window.addEventListener('load', function() {
+            showAlert('alert-loading', '설정을 불러오는 중...', 'alert-info');
+            loadSettings();
+        });
+    </script>
+</body>
+</html>
+)rawliteral";
+
+#endif
