diff --git a/.gitignore b/.gitignore
index 9b2add5..be9b7d2 100644
--- a/.gitignore
+++ b/.gitignore
@@ -49,3 +49,4 @@ client/build/
 # Ignore coverage
 coverage/
 dist/
+新增功能.md
\ No newline at end of file
diff --git a/client/css/phone.css b/client/css/phone.css
index 44545dc..4119563 100644
--- a/client/css/phone.css
+++ b/client/css/phone.css
@@ -70,10 +70,9 @@
 
 	* {
 		touch-action: pan-y;
-	}
-
-	.sidebar,
-	.rightbar {
+	}	.sidebar,
+	.rightbar,
+	.settings-sidebar {
 		position: fixed;
 		top: 0;
 		bottom: 0;
@@ -95,6 +94,19 @@
 		transform: translateX(0);
 	}
 
+	.settings-sidebar {
+		left: 0;
+		max-width: 80vw;
+		width: 80vw !important;
+		transform: translateX(-100%);
+		border-right: 1px solid #e0e0e0;
+		z-index: 1001; /* Higher than normal sidebar */
+	}
+
+	.settings-sidebar.mobile-open {
+		transform: translateX(0);
+	}
+
 	.rightbar {
 		right: 0;
 		max-width: 70vw;
@@ -143,11 +155,11 @@
 	.mobile-info-btn:active {
 		background: #e0e0e0;
 		transform: scale(0.93);
-	}
-
-	.settings-panel-card {
+	}	.settings-panel-card {
 		left: 2vw !important;
 	}
+	
+	/* Settings sidebar mobile styles - removed duplicate rules since they are above */
 }
 
 .member.private-chat-active {
diff --git a/client/css/style.css b/client/css/style.css
index 1087509..62660aa 100644
--- a/client/css/style.css
+++ b/client/css/style.css
@@ -52,74 +52,102 @@ body {
 	display: block;
 }
 
-.settings-panel {
-	display: none;
-	position: fixed;
-	left: 0;
-	top: 0;
-	right: 0;
-	bottom: 0;
-	z-index: 9999;
-	pointer-events: none;
-	background: none;
-}
-
-.settings-panel-card {
+/* New settings sidebar styles */
+.settings-sidebar {
+	width: 250px;
 	background: #fff;
-	border-radius: 16px;
-	box-shadow: 0 2px 24px rgba(60, 80, 100, 0.18);
-	padding: 15px 15px 15px 15px;
-	min-width: 210px;
-	position: absolute;
+	border-right: 1px solid #e0e0e0;
 	display: flex;
 	flex-direction: column;
-	gap: 10px;
-	pointer-events: auto;
-	opacity: 0;
-	transform: translateY(-10px) scale(0.95);
-	transition: opacity 0.3s ease, transform 0.3s ease;
+	box-shadow: 2px 0 8px #e0e0e0a0;
+	transition: width 0.3s ease;
+	position: relative;
 }
 
-.settings-panel-card.open-anim {
-	opacity: 1;
-	transform: translateY(0) scale(1);
+.settings-header {
+	display: flex;
+	align-items: center;
+	padding: 17.2px 18px 10px 17px;
+	background: #fff;
+	border-bottom: 1px solid #dcdcdc;
+	position: relative;
 }
 
-.settings-panel-card.close-anim {
-	opacity: 0;
-	transform: translateY(-10px) scale(0.95);
+.settings-back-btn {
+	background: none;
+	border: none;
+	cursor: pointer;
+	padding: 4px;
+	border-radius: 50%;
+	display: flex;
+	align-items: center;
+	justify-content: center;
+	transition: background-color 0.2s ease;
+	margin-right: 12px;
+}
+
+.settings-back-btn:hover {
+	background: #f5f5f5;
 }
 
 .settings-title {
 	font-size: 1.3rem;
 	font-weight: 600;
-	margin-bottom: 10px;
+	margin: 0;
 	color: #30a8f7;
-	text-align: left;
+}
+
+.settings-content {
+	flex: 1;
+	padding: 20px;
+	overflow-y: auto;
+	background: #fff;
+}
+
+.settings-section {
+	margin-bottom: 24px;
+}
+
+.settings-section-title {
+	font-size: 1.1rem;
+	font-weight: 600;
+	margin-bottom: 12px;
+	color: #222;
+	border-bottom: 1px solid #f0f0f0;
+	padding-bottom: 8px;
 }
 
 .settings-item {
 	display: flex;
 	align-items: center;
 	justify-content: space-between;
-	font-size: 1.08rem;
-	color: #222;
-	margin-bottom: 8px;
-}
-
-.settings-item select {
 	font-size: 1rem;
-	border-radius: 8px;
-	border: 1px solid #e0e0e0;
-	padding: 4px 10px;
-	background: #fafbfc;
-	outline: none;
-	transition: border-color 0.2s ease, background-color 0.2s ease;
+	color: #222;
+	margin-bottom: 12px;
+	padding: 8px 0;
 }
 
-.settings-item select:focus {
-	border-color: #30a8f7;
-	background: #fff;
+.settings-item-label {
+	flex: 1;
+	margin-right: 12px;
+}
+
+.settings-item-description {
+	font-size: 0.9rem;
+	color: #666;
+	margin-top: 4px;
+}
+
+/* Old settings panel - hide */
+.settings-panel {
+	display: none !important;
+}
+
+/* Old settings panel styles - remove */
+.settings-panel-card,
+.settings-panel-card.open-anim,
+.settings-panel-card.close-anim {
+	display: none !important;
 }
 
 .switch {
diff --git a/client/index.html b/client/index.html
index 562aaa8..813b838 100644
--- a/client/index.html
+++ b/client/index.html
@@ -15,10 +15,23 @@
 			<!-- 登录表单内容将由JavaScript动态生成 -->
 			<!-- Login form content will be dynamically generated by JavaScript -->
 		</form>
-	</div>
-	<div class="container" id="chat-container" style="display:none;">
+	</div>	<div class="container" id="chat-container" style="display:none;">
 		<div class="mobile-sidebar-mask" id="mobile-sidebar-mask"></div>
 		<div class="mobile-rightbar-mask" id="mobile-rightbar-mask"></div>
+		<!-- Settings panel as a sidebar replacement -->
+		<div class="settings-sidebar" id="settings-sidebar" style="display:none;">
+			<div class="settings-header">
+				<button class="settings-back-btn" id="settings-back-btn" title="返回" aria-label="返回">
+					<svg width="24px" height="24px" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
+						<path d="M15 18L9 12L15 6" stroke="#808080" stroke-width="2" stroke-linecap="round" stroke-linejoin="round"/>
+					</svg>
+				</button>
+				<h2 class="settings-title">设置</h2>
+			</div>
+			<div class="settings-content" id="settings-content">
+				<!-- Settings content will be populated by JavaScript -->
+			</div>
+		</div>
 		<div class="sidebar" id="sidebar">
 			<div class="sidebar-user"> <span class="avatar" id="sidebar-user-avatar"></span> <span class="sidebar-username" id="sidebar-username">My Name</span> <button class="settings-btn" id="settings-btn" title="设置" aria-label="设置"> <svg width="30px" height="30px" viewBox="0 0 24 24" fill="none"
 						xmlns="http://www.w3.org/2000/svg">
diff --git a/client/js/main.js b/client/js/main.js
index 56c3613..e8e7d75 100644
--- a/client/js/main.js
+++ b/client/js/main.js
@@ -112,7 +112,6 @@ window.addEventListener('DOMContentLoaded', () => {
 	setupImagePreview();
 	setupEmojiPicker();
 	initSettings();
-
 	const settingsBtn = $id('settings-btn'); // 设置按钮 / Settings button
 	if (settingsBtn) {
 		settingsBtn.onclick = (e) => {
@@ -121,17 +120,16 @@ window.addEventListener('DOMContentLoaded', () => {
 		}
 	}
 
-	// 点击其他地方时关闭设置面板
-	// Close settings panel when clicking outside
-	document.addEventListener('click', (ev) => {
-		const panel = $id('settings-panel');
-		if (panel && panel.style.display === 'block') {
-			const card = panel.querySelector('.settings-panel-card');
-			if (card && !card.contains(ev.target) && ev.target.id !== 'settings-btn') {
-				closeSettingsPanel();
-			}
+	// 设置返回按钮事件处理 / Settings back button event handler
+	const settingsBackBtn = $id('settings-back-btn');
+	if (settingsBackBtn) {
+		settingsBackBtn.onclick = (e) => {
+			e.stopPropagation();
+			closeSettingsPanel(); // 关闭设置面板 / Close settings panel
 		}
-	});
+	}
+	// 点击其他地方时关闭设置面板 (已移除，因为现在使用侧边栏形式)
+	// Close settings panel when clicking outside (removed since we now use sidebar format)
 
 	const input = document.querySelector('.input-message-input'); // 消息输入框 / Message input box
 	if (input) {
diff --git a/client/js/ui.js b/client/js/ui.js
index 6c18e5e..9b8b2ac 100644
--- a/client/js/ui.js
+++ b/client/js/ui.js
@@ -16,6 +16,9 @@ import {
 import {
 	$id
 } from './util.dom.js';
+import {
+	closeSettingsPanel
+} from './util.settings.js';
 
 // Render the main header
 // 渲染主标题栏
@@ -37,6 +40,7 @@ export function renderMainHeader() {
 export function setupMobileUIHandlers() {
 	const sidebar = document.getElementById('sidebar');
 	const rightbar = document.getElementById('rightbar');
+	const settingsSidebar = document.getElementById('settings-sidebar');
 	const mobileMenuBtn = document.getElementById('mobile-menu-btn');
 	const mobileInfoBtn = document.getElementById('mobile-info-btn');
 	const sidebarMask = document.getElementById('mobile-sidebar-mask');
@@ -66,10 +70,14 @@ export function setupMobileUIHandlers() {
 			e.stopPropagation();
 			sidebar.classList.add('mobile-open');
 			sidebarMask.classList.add('active')
-		};
-		sidebarMask.onclick = function() {
-			sidebar.classList.remove('mobile-open');
-			sidebarMask.classList.remove('active')
+		};		sidebarMask.onclick = function() {
+			// Check if settings sidebar is open
+			if (settingsSidebar && settingsSidebar.classList.contains('mobile-open')) {
+				closeSettingsPanel();
+			} else {
+				sidebar.classList.remove('mobile-open');
+				sidebarMask.classList.remove('active');
+			}
 		}
 	}
 	if (mobileInfoBtn && rightbar && rightbarMask) {
@@ -82,8 +90,7 @@ export function setupMobileUIHandlers() {
 			rightbar.classList.remove('mobile-open');
 			rightbarMask.classList.remove('active')
 		}
-	}
-	document.addEventListener('click', function(ev) {
+	}	document.addEventListener('click', function(ev) {
 		if (!isMobile()) return;
 		if (sidebar && sidebar.classList.contains('mobile-open')) {
 			if (!sidebar.contains(ev.target) && ev.target !== mobileMenuBtn) {
@@ -91,6 +98,11 @@ export function setupMobileUIHandlers() {
 				if (sidebarMask) sidebarMask.classList.remove('active')
 			}
 		}
+		if (settingsSidebar && settingsSidebar.classList.contains('mobile-open')) {
+			if (!settingsSidebar.contains(ev.target)) {
+				closeSettingsPanel();
+			}
+		}
 		if (rightbar && rightbar.classList.contains('mobile-open')) {
 			if (!rightbar.contains(ev.target) && ev.target !== mobileInfoBtn) {
 				rightbar.classList.remove('mobile-open');
diff --git a/client/js/util.settings.js b/client/js/util.settings.js
index f5f027d..eabb295 100644
--- a/client/js/util.settings.js
+++ b/client/js/util.settings.js
@@ -64,19 +64,38 @@ function askNotificationPermission(callback) {
 // Setup the settings panel UI
 // 设置设置面板 UI
 function setupSettingsPanel() {
-	let panel = $id('settings-panel');
-	if (!panel) {
-		panel = createElement('div', {
-			id: 'settings-panel',
-			class: 'settings-panel'
-		}, `<div class="settings-panel-card"><div class="settings-title">Settings</div><div class="settings-item"><span>Desktop Notification</span><label class="switch"><input type="checkbox"id="settings-notify"><span class="slider"></span></label></div><div class="settings-item"><span>Sound Notification</span><label class="switch"><input type="checkbox"id="settings-sound"><span class="slider"></span></label></div></div>`);
-		document.body.appendChild(panel)
-	}
+	const settingsSidebar = $id('settings-sidebar');
+	const settingsContent = $id('settings-content');
+	if (!settingsSidebar || !settingsContent) return;
+
 	const settings = loadSettings();
-	const notifyCheckbox = $('#settings-notify', panel);
-	const soundCheckbox = $('#settings-sound', panel);
-	if (notifyCheckbox) notifyCheckbox.checked = !!settings.notify;
-	if (soundCheckbox) soundCheckbox.checked = !!settings.sound;
+	// Create settings content HTML
+	settingsContent.innerHTML = `
+		<div class="settings-section">
+			<div class="settings-section-title">通知设置</div>
+			<div class="settings-item">
+				<div class="settings-item-label">
+					<div>桌面通知</div>
+				</div>
+				<label class="switch">
+					<input type="checkbox" id="settings-notify" ${settings.notify ? 'checked' : ''}>
+					<span class="slider"></span>
+				</label>
+			</div>
+			<div class="settings-item">
+				<div class="settings-item-label">
+					<div>声音通知</div>
+				</div>
+				<label class="switch">
+					<input type="checkbox" id="settings-sound" ${settings.sound ? 'checked' : ''}>
+					<span class="slider"></span>
+				</label>
+			</div>
+		</div>
+	`;
+
+	const notifyCheckbox = $('#settings-notify', settingsContent);
+	const soundCheckbox = $('#settings-sound', settingsContent);
 	on(notifyCheckbox, 'change', e => {
 		const checked = e.target.checked;
 		if (checked) {
@@ -91,13 +110,12 @@ function setupSettingsPanel() {
 					settings.sound = false;
 					if (soundCheckbox) soundCheckbox.checked = false;
 					saveSettings(settings);
-					applySettings(settings);
-					// 防止重复通知，添加一个标志位
-					if (!panel._notificationShown) {
+					applySettings(settings);					// 防止重复通知，添加一个标志位
+					if (!settingsSidebar._notificationShown) {
 						new Notification('Notifications enabled', {
 							body: 'You will receive alerts here.'
 						});
-						panel._notificationShown = true; // 设置标志位
+						settingsSidebar._notificationShown = true; // 设置标志位
 					}
 				} else {
 					settings.notify = false;
@@ -110,10 +128,9 @@ function setupSettingsPanel() {
 		} else {
 			settings.notify = false;
 			saveSettings(settings);
-			applySettings(settings);
-			// 重置标志位
-			if (panel._notificationShown) {
-				panel._notificationShown = false;
+			applySettings(settings);			// 重置标志位
+			if (settingsSidebar._notificationShown) {
+				settingsSidebar._notificationShown = false;
 			}
 		}
 	});
@@ -128,41 +145,62 @@ function setupSettingsPanel() {
 	});
 }
 
+// Check if device is mobile
+function isMobile() {
+	return window.innerWidth <= 768;
+}
+
 // Open the settings panel
 // 打开设置面板
 function openSettingsPanel() {
+	const settingsSidebar = $id('settings-sidebar');
+	const sidebar = $id('sidebar');
+	const sidebarMask = $id('mobile-sidebar-mask');
+	
+	if (!settingsSidebar || !sidebar) return;
+	
+	if (isMobile()) {
+		// Mobile: hide main sidebar and show settings sidebar with mask
+		sidebar.classList.remove('mobile-open');
+		settingsSidebar.style.display = 'flex';
+		settingsSidebar.classList.add('mobile-open');
+		if (sidebarMask) {
+			sidebarMask.classList.add('active');
+		}
+	} else {
+		// Desktop: hide main sidebar and show settings sidebar
+		sidebar.style.display = 'none';
+		settingsSidebar.style.display = 'flex';
+	}
+	
+	// Setup settings content
 	setupSettingsPanel();
-	const panel = $id('settings-panel');
-	const btn = $id('settings-btn');
-	if (!btn || !panel) return;
-	if (panel.style.display === 'block') return;
-	const btnRect = btn.getBoundingClientRect();
-	panel.style.display = 'block';
-	const card = $('.settings-panel-card', panel);
-	if (!card) return;
-	card.style.position = 'fixed';
-	card.style.left = btnRect.left + 'px';
-	card.style.top = (btnRect.bottom + 8) + 'px';
-	card.style.transform = 'translateX(0)';
-	removeClass(card, 'close-anim');
-	// 强制触发重绘，然后添加打开动画
-	card.offsetHeight; // 强制重绘
-	addClass(card, 'open-anim');
 }
 
 // Close the settings panel
 // 关闭设置面板
 function closeSettingsPanel() {
-	const panel = $id('settings-panel');
-	if (!panel) return;
-	const card = $('.settings-panel-card', panel);
-	if (!card) return;
-	removeClass(card, 'open-anim');
-	addClass(card, 'close-anim');
-	setTimeout(() => {
-		panel.style.display = 'none';
-		removeClass(card, 'close-anim')
-	}, 300)
+	const settingsSidebar = $id('settings-sidebar');
+	const sidebar = $id('sidebar');
+	const sidebarMask = $id('mobile-sidebar-mask');
+	
+	if (!settingsSidebar || !sidebar) return;
+	
+	if (isMobile()) {
+		// Mobile: hide settings sidebar and mask, show main sidebar if needed
+		settingsSidebar.classList.remove('mobile-open');
+		if (sidebarMask) {
+			sidebarMask.classList.remove('active');
+		}
+		// Don't auto-show main sidebar on mobile - let user click menu button
+		setTimeout(() => {
+			settingsSidebar.style.display = 'none';
+		}, 300); // Wait for animation to complete
+	} else {
+		// Desktop: hide settings sidebar and show main sidebar
+		settingsSidebar.style.display = 'none';
+		sidebar.style.display = 'flex';
+	}
 }
 
 // Initialize settings on page load