diff --git a/app/Views/login.php b/app/Views/login.php
index dd66bf4..f521755 100644
--- a/app/Views/login.php
+++ b/app/Views/login.php
@@ -8,6 +8,7 @@
                 <path d="M8 16v2M16 16v2M12 16v3"/>
             </svg>
             <h1>AI Chat</h1>
+            <p class="login-subtitle">登录你的 AI 对话平台</p>
         </div>
         <div id="loginError" class="alert alert-error" style="display:none;"></div>
         <form id="loginForm">
@@ -19,7 +20,7 @@
                 <label for="password">密码</label>
                 <input type="password" id="password" name="password" required autocomplete="current-password" placeholder="请输入密码">
             </div>
-            <button type="submit" class="btn btn-primary btn-block" id="loginBtn">登录</button>
+            <button type="submit" class="btn btn-primary btn-block" id="loginBtn" style="margin-top:8px;">登录</button>
         </form>
     </div>
 </div>
diff --git a/assets/css/style.css b/assets/css/style.css
index 99495ce..119d6ac 100644
--- a/assets/css/style.css
+++ b/assets/css/style.css
@@ -1,25 +1,40 @@
-/* CSS 变量 */
+/* ========================================
+   CSS 变量
+   ======================================== */
 :root {
     --primary: #4a90d9;
     --primary-hover: #357abd;
+    --primary-light: rgba(74, 144, 217, 0.12);
+    --primary-glow: rgba(74, 144, 217, 0.25);
     --bg-primary: #1a1a2e;
     --bg-secondary: #16213e;
     --bg-card: #1e2a45;
     --bg-input: #0f1b33;
     --text-primary: #e0e0e0;
-    --text-secondary: #a0a0a0;
+    --text-secondary: #8892a8;
+    --text-hint: #5c6a85;
     --border-color: #2a3a5c;
+    --border-light: rgba(42, 58, 92, 0.6);
     --success: #4caf50;
+    --success-bg: rgba(76, 175, 80, 0.1);
     --danger: #f44336;
+    --danger-bg: rgba(244, 67, 54, 0.1);
     --warning: #ff9800;
     --sidebar-width: 260px;
     --toolbar-height: 50px;
     --input-height: 120px;
     --radius: 8px;
-    --font-family: system-ui, -apple-system, sans-serif;
+    --radius-lg: 12px;
+    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
+    --shadow-sm: 0 2px 8px rgba(0,0,0,0.15);
+    --shadow-md: 0 4px 16px rgba(0,0,0,0.2);
+    --shadow-lg: 0 8px 32px rgba(0,0,0,0.3);
+    --transition: 0.2s ease;
 }
 
-/* Reset */
+/* ========================================
+   Reset
+   ======================================== */
 *, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
 
 body {
@@ -28,87 +43,317 @@ body {
     color: var(--text-primary);
     line-height: 1.6;
     min-height: 100vh;
+    -webkit-font-smoothing: antialiased;
+    -moz-osx-font-smoothing: grayscale;
 }
 
-/* 登录页样式 */
+/* ========================================
+   登录页
+   ======================================== */
 .login-container {
     display: flex;
     justify-content: center;
     align-items: center;
     min-height: 100vh;
     padding: 20px;
-    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
+    background:
+        radial-gradient(ellipse at 20% 50%, rgba(74, 144, 217, 0.08) 0%, transparent 50%),
+        radial-gradient(ellipse at 80% 20%, rgba(74, 144, 217, 0.05) 0%, transparent 50%),
+        linear-gradient(160deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
 }
 
 .login-card {
     background: var(--bg-card);
-    border-radius: 12px;
+    border-radius: var(--radius-lg);
     padding: 48px 40px;
     width: 100%;
     max-width: 420px;
-    box-shadow: 0 8px 32px rgba(0,0,0,0.3);
+    box-shadow: var(--shadow-lg);
     border: 1px solid var(--border-color);
 }
 
 .login-logo {
     text-align: center;
-    margin-bottom: 36px;
+    margin-bottom: 40px;
 }
 
 .login-logo .logo-icon {
-    width: 48px;
-    height: 48px;
+    width: 56px;
+    height: 56px;
     color: var(--primary);
-    margin-bottom: 12px;
+    margin-bottom: 16px;
+    filter: drop-shadow(0 2px 8px rgba(74, 144, 217, 0.3));
 }
 
 .login-logo h1 {
-    font-size: 24px;
+    font-size: 26px;
     color: var(--primary);
-    font-weight: 600;
+    font-weight: 700;
     letter-spacing: 0.5px;
+    margin-bottom: 4px;
 }
 
-/* 安装向导样式 */
+.login-subtitle {
+    font-size: 14px;
+    color: var(--text-secondary);
+    margin-top: 4px;
+}
+
+/* ========================================
+   安装向导页
+   ======================================== */
 .install-container {
-    max-width: 700px;
-    margin: 40px auto;
-    padding: 0 20px;
+    max-width: 720px;
+    margin: 0 auto;
+    padding: 48px 24px 32px;
+    min-height: 100vh;
+    display: flex;
+    flex-direction: column;
 }
 
-.install-container h1 svg {
+.install-header {
+    text-align: center;
+    margin-bottom: 40px;
+}
+
+.install-logo {
+    margin-bottom: 16px;
+}
+
+.install-logo svg {
+    width: 48px;
+    height: 48px;
     color: var(--primary);
+    filter: drop-shadow(0 2px 8px rgba(74, 144, 217, 0.3));
 }
 
+.install-header h1 {
+    font-size: 26px;
+    font-weight: 700;
+    color: var(--text-primary);
+    margin-bottom: 8px;
+}
+
+.install-subtitle {
+    font-size: 14px;
+    color: var(--text-secondary);
+    max-width: 400px;
+    margin: 0 auto;
+}
+
+.install-footer {
+    text-align: center;
+    padding: 24px 0 8px;
+    margin-top: auto;
+    font-size: 12px;
+    color: var(--text-hint);
+}
+
+/* 步骤指示器 */
 .step-indicator {
     display: flex;
     justify-content: space-between;
-    margin-bottom: 30px;
+    margin-bottom: 36px;
     padding: 0;
     list-style: none;
+    gap: 4px;
 }
 
 .step-indicator .step {
     flex: 1;
-    text-align: center;
-    padding: 10px;
-    font-size: 14px;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 8px;
+    padding: 12px 4px 0;
+    position: relative;
+}
+
+.step-indicator .step::after {
+    content: '';
+    position: absolute;
+    top: 0;
+    left: 0;
+    right: 0;
+    height: 3px;
+    background: var(--border-color);
+    border-radius: 2px;
+    transition: background var(--transition);
+}
+
+.step-indicator .step.active::after {
+    background: var(--primary);
+}
+
+.step-indicator .step.completed::after {
+    background: var(--success);
+}
+
+.step-num {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    width: 28px;
+    height: 28px;
+    border-radius: 50%;
+    background: var(--border-color);
     color: var(--text-secondary);
-    border-bottom: 3px solid var(--border-color);
-    transition: all 0.3s;
+    font-size: 13px;
+    font-weight: 600;
+    transition: all var(--transition);
 }
 
-.step-indicator .step.active {
+.step.active .step-num {
+    background: var(--primary);
+    color: #fff;
+    box-shadow: 0 2px 8px rgba(74, 144, 217, 0.35);
+}
+
+.step.completed .step-num {
+    background: var(--success);
+    color: #fff;
+}
+
+.step-label {
+    font-size: 12px;
+    color: var(--text-secondary);
+    white-space: nowrap;
+    transition: color var(--transition);
+}
+
+.step.active .step-label {
     color: var(--primary);
-    border-bottom-color: var(--primary);
+    font-weight: 600;
 }
 
-.step-indicator .step.completed {
+.step.completed .step-label {
     color: var(--success);
-    border-bottom-color: var(--success);
 }
 
-/* 通用表单样式 */
+/* 步骤内容卡片 */
+.step-content {
+    display: none;
+    background: var(--bg-card);
+    border-radius: var(--radius-lg);
+    padding: 32px;
+    border: 1px solid var(--border-color);
+    box-shadow: var(--shadow-sm);
+    animation: stepFadeIn 0.3s ease;
+}
+
+.step-content.active {
+    display: block;
+}
+
+@keyframes stepFadeIn {
+    from { opacity: 0; transform: translateY(8px); }
+    to { opacity: 1; transform: translateY(0); }
+}
+
+.step-header {
+    margin-bottom: 24px;
+}
+
+.step-header h2 {
+    font-size: 18px;
+    font-weight: 600;
+    margin-bottom: 6px;
+}
+
+.step-desc {
+    font-size: 13px;
+    color: var(--text-secondary);
+}
+
+/* 环境检查列表 */
+.check-list {
+    margin-bottom: 8px;
+}
+
+.check-item {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    padding: 12px 16px;
+    border-radius: var(--radius);
+    margin-bottom: 6px;
+    background: var(--bg-secondary);
+    transition: background var(--transition);
+}
+
+.check-item:last-child {
+    margin-bottom: 0;
+}
+
+.check-name {
+    font-size: 14px;
+    color: var(--text-primary);
+}
+
+.check-status {
+    display: flex;
+    align-items: center;
+    gap: 6px;
+    font-size: 13px;
+    font-weight: 600;
+}
+
+.check-status svg {
+    vertical-align: -2px;
+}
+
+.check-item.pass .check-status {
+    color: var(--success);
+}
+
+.check-item.fail .check-status {
+    color: var(--danger);
+}
+
+.check-item.fail {
+    background: var(--danger-bg);
+    border: 1px solid rgba(244, 67, 54, 0.2);
+}
+
+.check-item.pass {
+    border: 1px solid transparent;
+}
+
+/* 供应商配置卡片 */
+.provider-item {
+    background: var(--bg-secondary);
+    padding: 20px;
+    border-radius: var(--radius);
+    margin-bottom: 12px;
+    border: 1px solid var(--border-light);
+}
+
+.provider-item-header {
+    display: flex;
+    justify-content: space-between;
+    align-items: center;
+    margin-bottom: 16px;
+    padding-bottom: 12px;
+    border-bottom: 1px solid var(--border-light);
+}
+
+.provider-item-title {
+    font-size: 14px;
+    font-weight: 600;
+    color: var(--text-primary);
+}
+
+.provider-item .form-group {
+    margin-bottom: 12px;
+}
+
+.provider-item .form-group:last-child {
+    margin-bottom: 0;
+}
+
+/* ========================================
+   通用表单
+   ======================================== */
 .form-group {
     margin-bottom: 18px;
 }
@@ -119,20 +364,25 @@ body {
     font-size: 13px;
     font-weight: 500;
     color: var(--text-secondary);
-    letter-spacing: 0.3px;
 }
 
 .form-group input,
 .form-group select,
 .form-group textarea {
     width: 100%;
-    padding: 10px 12px;
+    padding: 10px 14px;
     background: var(--bg-input);
     border: 1px solid var(--border-color);
     border-radius: var(--radius);
     color: var(--text-primary);
     font-size: 14px;
-    transition: border-color 0.3s;
+    font-family: inherit;
+    transition: all var(--transition);
+}
+
+.form-group input::placeholder,
+.form-group textarea::placeholder {
+    color: var(--text-hint);
 }
 
 .form-group input:focus,
@@ -140,9 +390,43 @@ body {
 .form-group textarea:focus {
     outline: none;
     border-color: var(--primary);
+    box-shadow: 0 0 0 3px var(--primary-light);
 }
 
-/* 按钮 */
+/* 表单行（并排布局） */
+.form-row {
+    display: flex;
+    gap: 16px;
+}
+
+@media (max-width: 600px) {
+    .form-row {
+        flex-direction: column;
+        gap: 0;
+    }
+}
+
+/* 输入框+按钮行 */
+.input-action-row {
+    display: flex;
+    gap: 8px;
+}
+
+.input-action-row input {
+    flex: 1;
+}
+
+/* 表单提示文字 */
+.form-hint {
+    display: block;
+    margin-top: 4px;
+    font-size: 12px;
+    color: var(--text-hint);
+}
+
+/* ========================================
+   按钮
+   ======================================== */
 .btn {
     display: inline-flex;
     align-items: center;
@@ -152,10 +436,12 @@ body {
     border-radius: var(--radius);
     font-size: 14px;
     font-weight: 500;
+    font-family: inherit;
     cursor: pointer;
-    transition: all 0.2s ease;
+    transition: all var(--transition);
     text-decoration: none;
     line-height: 1.4;
+    white-space: nowrap;
 }
 
 .btn-primary {
@@ -166,11 +452,19 @@ body {
 .btn-primary:hover {
     background: var(--primary-hover);
     transform: translateY(-1px);
-    box-shadow: 0 2px 8px rgba(74, 144, 217, 0.3);
+    box-shadow: 0 4px 12px rgba(74, 144, 217, 0.35);
 }
 
 .btn-primary:active {
     transform: translateY(0);
+    box-shadow: none;
+}
+
+.btn-primary:disabled {
+    opacity: 0.6;
+    cursor: not-allowed;
+    transform: none;
+    box-shadow: none;
 }
 
 .btn-secondary {
@@ -184,6 +478,16 @@ body {
     color: var(--primary);
 }
 
+.btn-outline {
+    background: transparent;
+    color: var(--primary);
+    border: 1px solid var(--primary);
+}
+
+.btn-outline:hover {
+    background: var(--primary-light);
+}
+
 .btn-danger {
     background: var(--danger);
     color: white;
@@ -198,6 +502,12 @@ body {
     font-size: 12px;
 }
 
+.btn-lg {
+    padding: 12px 32px;
+    font-size: 15px;
+    font-weight: 600;
+}
+
 .btn-block {
     display: flex;
     width: 100%;
@@ -207,32 +517,39 @@ body {
 .btn-group {
     display: flex;
     gap: 10px;
-    margin-top: 24px;
+    margin-top: 28px;
     justify-content: flex-end;
 }
 
-/* 消息提示 */
+/* ========================================
+   消息提示
+   ======================================== */
 .alert {
     padding: 12px 16px;
     border-radius: var(--radius);
     margin-bottom: 16px;
     font-size: 14px;
     line-height: 1.5;
+    display: flex;
+    align-items: center;
+    gap: 8px;
 }
 
 .alert-error {
-    background: rgba(244, 67, 54, 0.1);
-    border: 1px solid var(--danger);
+    background: var(--danger-bg);
+    border: 1px solid rgba(244, 67, 54, 0.3);
     color: var(--danger);
 }
 
 .alert-success {
-    background: rgba(76, 175, 80, 0.1);
-    border: 1px solid var(--success);
+    background: var(--success-bg);
+    border: 1px solid rgba(76, 175, 80, 0.3);
     color: var(--success);
 }
 
-/* 配置页样式 */
+/* ========================================
+   配置页
+   ======================================== */
 .config-container {
     max-width: 900px;
     margin: 40px auto;
@@ -259,7 +576,7 @@ body {
 
 .config-section {
     background: var(--bg-card);
-    border-radius: 12px;
+    border-radius: var(--radius-lg);
     padding: 28px;
     margin-bottom: 24px;
     border: 1px solid var(--border-color);
@@ -273,13 +590,62 @@ body {
     border-bottom: 1px solid var(--border-color);
 }
 
-/* 响应式 */
+/* ========================================
+   响应式
+   ======================================== */
 @media (max-width: 768px) {
     .login-card {
-        padding: 24px;
+        padding: 32px 24px;
     }
-    .install-container,
+
+    .install-container {
+        padding: 24px 16px 16px;
+    }
+
+    .step-content {
+        padding: 24px 20px;
+    }
+
+    .step-label {
+        display: none;
+    }
+
+    .step-indicator {
+        gap: 0;
+    }
+
+    .install-header h1 {
+        font-size: 22px;
+    }
+
+    .install-subtitle {
+        font-size: 13px;
+    }
+
     .config-container {
         margin: 20px auto;
+        padding: 0 12px;
+    }
+
+    .config-header {
+        flex-direction: column;
+        align-items: flex-start;
+        gap: 12px;
+    }
+}
+
+@media (max-width: 480px) {
+    .login-card {
+        padding: 24px 20px;
+        border-radius: var(--radius);
+    }
+
+    .login-logo .logo-icon {
+        width: 44px;
+        height: 44px;
+    }
+
+    .login-logo h1 {
+        font-size: 22px;
     }
 }
diff --git a/public/install.php b/public/install.php
index 7128621..6dfad90 100644
--- a/public/install.php
+++ b/public/install.php
@@ -13,39 +13,54 @@ if (file_exists($configFile)) {
     <meta name="viewport" content="width=device-width, initial-scale=1.0">
     <title>AI Chat - 安装向导</title>
     <link rel="stylesheet" href="/assets/css/style.css">
-    <style>
-        .install-container { max-width: 700px; margin: 40px auto; padding: 0 20px; }
-        .step-content { display: none; background: var(--bg-card); border-radius: var(--radius); padding: 24px; }
-        .step-content.active { display: block; }
-        .check-item { display: flex; justify-content: space-between; padding: 8px 0; border-bottom: 1px solid var(--border-color); }
-        .check-item .status { font-weight: bold; }
-        .check-item .status.pass { color: var(--success); }
-        .check-item .status.fail { color: var(--danger); }
-        .provider-item { background: var(--bg-secondary); padding: 16px; border-radius: var(--radius); margin-bottom: 12px; }
-        .provider-item .form-group { margin-bottom: 8px; }
-        h1 { text-align: center; margin-bottom: 30px; color: var(--primary); }
-    </style>
 </head>
 <body>
     <div class="install-container">
-        <h1>
-            <svg viewBox="0 0 24 24" width="28" height="28" fill="none" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round" style="vertical-align:-6px;margin-right:10px;"><rect x="3" y="4" width="18" height="12" rx="3"/><circle cx="9" cy="10" r="1.5" fill="currentColor" stroke="none"/><circle cx="15" cy="10" r="1.5" fill="currentColor" stroke="none"/><path d="M8 16v2M16 16v2M12 16v3"/></svg>
-            AI Chat 安装向导
-        </h1>
-        
+        <!-- 标题区域 -->
+        <div class="install-header">
+            <div class="install-logo">
+                <svg viewBox="0 0 24 24" width="40" height="40" fill="none" stroke="currentColor" stroke-width="1.5" stroke-linecap="round" stroke-linejoin="round">
+                    <rect x="3" y="4" width="18" height="12" rx="3"/>
+                    <circle cx="9" cy="10" r="1.5" fill="currentColor" stroke="none"/>
+                    <circle cx="15" cy="10" r="1.5" fill="currentColor" stroke="none"/>
+                    <path d="M8 16v2M16 16v2M12 16v3"/>
+                </svg>
+            </div>
+            <h1>AI Chat 安装向导</h1>
+            <p class="install-subtitle">跟随引导完成初始配置，快速启用你的 AI 对话平台</p>
+        </div>
+
         <!-- 步骤指示器 -->
         <ul class="step-indicator">
-            <li class="step active" data-step="1">1. 环境检查</li>
-            <li class="step" data-step="2">2. 数据库配置</li>
-            <li class="step" data-step="3">3. 应用配置</li>
-            <li class="step" data-step="4">4. 管理员账户</li>
-            <li class="step" data-step="5">5. AI供应商</li>
+            <li class="step active" data-step="1">
+                <span class="step-num">1</span>
+                <span class="step-label">环境检查</span>
+            </li>
+            <li class="step" data-step="2">
+                <span class="step-num">2</span>
+                <span class="step-label">数据库</span>
+            </li>
+            <li class="step" data-step="3">
+                <span class="step-num">3</span>
+                <span class="step-label">应用配置</span>
+            </li>
+            <li class="step" data-step="4">
+                <span class="step-num">4</span>
+                <span class="step-label">管理员</span>
+            </li>
+            <li class="step" data-step="5">
+                <span class="step-num">5</span>
+                <span class="step-label">AI 供应商</span>
+            </li>
         </ul>
 
         <!-- 步骤1：环境检查 -->
         <div class="step-content active" id="step1">
-            <h2>环境检查</h2>
-            <div id="envChecks">
+            <div class="step-header">
+                <h2>环境检查</h2>
+                <p class="step-desc">检查服务器运行环境是否满足安装要求</p>
+            </div>
+            <div id="envChecks" class="check-list">
                 <!-- 由 JS 动态填充 -->
             </div>
             <div class="btn-group">
@@ -55,48 +70,62 @@ if (file_exists($configFile)) {
 
         <!-- 步骤2：数据库配置 -->
         <div class="step-content" id="step2">
-            <h2>数据库配置</h2>
-            <div class="form-group">
-                <label>主机地址</label>
-                <input type="text" id="dbHost" value="127.0.0.1" placeholder="数据库主机">
+            <div class="step-header">
+                <h2>数据库配置</h2>
+                <p class="step-desc">填写 MySQL 数据库连接信息</p>
             </div>
-            <div class="form-group">
-                <label>端口</label>
-                <input type="number" id="dbPort" value="3306" placeholder="数据库端口">
+            <div class="form-row">
+                <div class="form-group" style="flex:2">
+                    <label>主机地址</label>
+                    <input type="text" id="dbHost" value="127.0.0.1" placeholder="数据库主机">
+                </div>
+                <div class="form-group" style="flex:1">
+                    <label>端口</label>
+                    <input type="number" id="dbPort" value="3306" placeholder="端口号">
+                </div>
             </div>
             <div class="form-group">
                 <label>数据库名</label>
                 <input type="text" id="dbName" placeholder="数据库名称">
             </div>
-            <div class="form-group">
-                <label>用户名</label>
-                <input type="text" id="dbUser" placeholder="数据库用户名">
-            </div>
-            <div class="form-group">
-                <label>密码</label>
-                <input type="password" id="dbPassword" placeholder="数据库密码">
+            <div class="form-row">
+                <div class="form-group" style="flex:1">
+                    <label>用户名</label>
+                    <input type="text" id="dbUser" placeholder="数据库用户名">
+                </div>
+                <div class="form-group" style="flex:1">
+                    <label>密码</label>
+                    <input type="password" id="dbPassword" placeholder="数据库密码">
+                </div>
             </div>
             <div id="dbTestResult"></div>
             <div class="btn-group">
                 <button class="btn btn-secondary" onclick="InstallWizard.prevStep()">上一步</button>
-                <button class="btn btn-secondary" onclick="InstallWizard.testDb()">测试连接</button>
+                <button class="btn btn-outline" onclick="InstallWizard.testDb()">
+                    <svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round" style="margin-right:4px;"><path d="M22 11.08V12a10 10 0 11-5.93-9.14"/><polyline points="22 4 12 14.01 9 11.01"/></svg>
+                    测试连接
+                </button>
                 <button class="btn btn-primary" onclick="InstallWizard.nextStep()">下一步</button>
             </div>
         </div>
 
         <!-- 步骤3：应用配置 -->
         <div class="step-content" id="step3">
-            <h2>应用配置</h2>
+            <div class="step-header">
+                <h2>应用配置</h2>
+                <p class="step-desc">设置 JWT 令牌参数，用于用户认证加密</p>
+            </div>
             <div class="form-group">
                 <label>JWT 密钥</label>
-                <div style="display:flex;gap:8px;">
-                    <input type="text" id="jwtSecret" placeholder="留空则自动生成" style="flex:1;">
-                    <button class="btn btn-secondary btn-sm" onclick="document.getElementById('jwtSecret').value=InstallWizard.generateSecret()">自动生成</button>
+                <div class="input-action-row">
+                    <input type="text" id="jwtSecret" placeholder="留空则自动生成安全密钥">
+                    <button class="btn btn-outline btn-sm" onclick="document.getElementById('jwtSecret').value=InstallWizard.generateSecret()">自动生成</button>
                 </div>
             </div>
             <div class="form-group">
                 <label>JWT 过期时间（秒）</label>
                 <input type="number" id="jwtExpiry" value="86400" placeholder="默认 86400（24小时）">
+                <span class="form-hint">默认 86400 秒（24 小时），可根据需要调整</span>
             </div>
             <div class="btn-group">
                 <button class="btn btn-secondary" onclick="InstallWizard.prevStep()">上一步</button>
@@ -106,18 +135,23 @@ if (file_exists($configFile)) {
 
         <!-- 步骤4：管理员账户 -->
         <div class="step-content" id="step4">
-            <h2>创建管理员账户</h2>
+            <div class="step-header">
+                <h2>创建管理员账户</h2>
+                <p class="step-desc">设置管理员登录凭据，安装后可在系统中修改</p>
+            </div>
             <div class="form-group">
                 <label>用户名</label>
                 <input type="text" id="adminUsername" placeholder="管理员用户名">
             </div>
-            <div class="form-group">
-                <label>密码</label>
-                <input type="password" id="adminPassword" placeholder="至少6位密码">
-            </div>
-            <div class="form-group">
-                <label>确认密码</label>
-                <input type="password" id="adminPasswordConfirm" placeholder="再次输入密码">
+            <div class="form-row">
+                <div class="form-group" style="flex:1">
+                    <label>密码</label>
+                    <input type="password" id="adminPassword" placeholder="至少6位密码">
+                </div>
+                <div class="form-group" style="flex:1">
+                    <label>确认密码</label>
+                    <input type="password" id="adminPasswordConfirm" placeholder="再次输入密码">
+                </div>
             </div>
             <div class="btn-group">
                 <button class="btn btn-secondary" onclick="InstallWizard.prevStep()">上一步</button>
@@ -127,18 +161,28 @@ if (file_exists($configFile)) {
 
         <!-- 步骤5：AI供应商 -->
         <div class="step-content" id="step5">
-            <h2>AI 供应商配置</h2>
-            <p style="color:var(--text-secondary);margin-bottom:16px;">至少配置一个 AI 供应商</p>
+            <div class="step-header">
+                <h2>AI 供应商配置</h2>
+                <p class="step-desc">至少配置一个 AI 供应商，安装后可在设置中添加更多</p>
+            </div>
             <div id="providerList">
                 <!-- 由 JS 动态管理 -->
             </div>
-            <button class="btn btn-secondary" onclick="InstallWizard.addProvider()" style="margin-top:8px;">+ 添加供应商</button>
-            <div id="installResult"></div>
+            <button class="btn btn-outline" onclick="InstallWizard.addProvider()" style="margin-top:12px;width:100%;">
+                <svg viewBox="0 0 24 24" width="14" height="14" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" style="margin-right:4px;"><path d="M12 5v14M5 12h14"/></svg>
+                添加供应商
+            </button>
+            <div id="installResult" style="margin-top:16px;"></div>
             <div class="btn-group">
                 <button class="btn btn-secondary" onclick="InstallWizard.prevStep()">上一步</button>
-                <button class="btn btn-primary" id="installBtn" onclick="InstallWizard.runInstall()">完成安装</button>
+                <button class="btn btn-primary btn-lg" id="installBtn" onclick="InstallWizard.runInstall()">完成安装</button>
             </div>
         </div>
+
+        <!-- 底部版本信息 -->
+        <div class="install-footer">
+            AI Chat &middot; v1.0
+        </div>
     </div>
 
     <script>
@@ -162,16 +206,20 @@ if (file_exists($configFile)) {
             
             const container = document.getElementById('envChecks');
             container.innerHTML = checks.map(c => `
-                <div class="check-item">
-                    <span>${c.name}</span>
-                    <span class="status ${c.pass ? 'pass' : 'fail'}">${c.pass ? '通过' : '未通过'}</span>
+                <div class="check-item ${c.pass ? 'pass' : 'fail'}">
+                    <span class="check-name">${c.name}</span>
+                    <span class="check-status">
+                        ${c.pass 
+                            ? '<svg viewBox="0 0 24 24" width="16" height="16" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"><polyline points="20 6 9 17 4 12"/></svg> 通过'
+                            : '<svg viewBox="0 0 24 24" width="16" height="16" fill="none" stroke="currentColor" stroke-width="2.5" stroke-linecap="round" stroke-linejoin="round"><path d="M18 6L6 18M6 6l12 12"/></svg> 未通过'
+                        }
+                    </span>
                 </div>
             `).join('');
         },
 
         nextStep() {
             if (this.currentStep === 4) {
-                // 验证管理员密码
                 const pwd = document.getElementById('adminPassword').value;
                 const confirm = document.getElementById('adminPasswordConfirm').value;
                 const username = document.getElementById('adminUsername').value;
@@ -229,9 +277,23 @@ if (file_exists($configFile)) {
             const index = list.children.length;
             const html = `
                 <div class="provider-item" data-index="${index}">
-                    <div class="form-group">
-                        <label>供应商名称</label>
-                        <input type="text" class="provider-name" placeholder="如：OpenAI、DeepSeek">
+                    <div class="provider-item-header">
+                        <span class="provider-item-title">供应商 #${index + 1}</span>
+                        ${index > 0 ? '<button class="btn btn-danger btn-sm" onclick="this.closest(\'.provider-item\').remove()">删除</button>' : ''}
+                    </div>
+                    <div class="form-row">
+                        <div class="form-group" style="flex:1">
+                            <label>供应商名称</label>
+                            <input type="text" class="provider-name" placeholder="如：OpenAI、DeepSeek">
+                        </div>
+                        <div class="form-group" style="flex:1">
+                            <label>供应商类型</label>
+                            <select class="provider-type">
+                                <option value="newapi">OpenAI 兼容</option>
+                                <option value="openai">OpenAI 官方</option>
+                                <option value="claude">Claude (Anthropic)</option>
+                            </select>
+                        </div>
                     </div>
                     <div class="form-group">
                         <label>API URL</label>
@@ -245,15 +307,6 @@ if (file_exists($configFile)) {
                         <label>可用模型（逗号分隔）</label>
                         <input type="text" class="provider-models" placeholder="如：gpt-3.5-turbo, gpt-4">
                     </div>
-                    <div class="form-group">
-                        <label>供应商类型</label>
-                        <select class="provider-type">
-                            <option value="newapi">OpenAI 兼容</option>
-                            <option value="openai">OpenAI 官方</option>
-                            <option value="claude">Claude (Anthropic)</option>
-                        </select>
-                    </div>
-                    ${index > 0 ? '<button class="btn btn-danger btn-sm" onclick="this.parentElement.remove()">删除</button>' : ''}
                 </div>
             `;
             list.insertAdjacentHTML('beforeend', html);