diff --git a/css/styles.css b/css/styles.css
new file mode 100644
index 0000000..39e74ee
--- /dev/null
+++ b/css/styles.css
@@ -0,0 +1,203 @@
+/* 基本样式重置 */
+* {
+    margin: 0;
+    padding: 0;
+    box-sizing: border-box;
+}
+
+body {
+    font-family: 'Microsoft YaHei', Arial, sans-serif;
+    line-height: 1.6;
+    color: #333;
+    background-color: #f4f4f4;
+}
+
+.container {
+    width: 90%;
+    max-width: 1200px;
+    margin: 0 auto;
+    padding: 0 20px;
+}
+
+/* 头部样式 */
+header {
+    background-color: #3498db;
+    color: #fff;
+    padding: 1rem 0;
+    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
+}
+
+header h1 {
+    margin: 0;
+    font-size: 1.8rem;
+}
+
+nav {
+    margin-top: 1rem;
+}
+
+nav ul {
+    list-style: none;
+    display: flex;
+}
+
+nav ul li {
+    margin-right: 20px;
+}
+
+nav ul li a {
+    color: #fff;
+    text-decoration: none;
+    padding: 5px 10px;
+    border-radius: 3px;
+    transition: background-color 0.3s;
+}
+
+nav ul li a:hover,
+nav ul li a.active {
+    background-color: rgba(255,255,255,0.2);
+}
+
+/* 页脚样式 */
+footer {
+    background-color: #333;
+    color: #fff;
+    padding: 1rem 0;
+    margin-top: 2rem;
+    text-align: center;
+}
+
+/* 主内容区域 */
+main {
+    padding: 2rem 0;
+}
+
+.welcome-section {
+    background-color: #fff;
+    padding: 2rem;
+    border-radius: 5px;
+    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
+    margin-top: 2rem;
+}
+
+/* 登录页面样式 */
+.login-page {
+    background-color: #f9f9f9;
+    height: 100vh;
+    display: flex;
+    align-items: center;
+    justify-content: center;
+}
+
+.login-container {
+    width: 100%;
+    max-width: 400px;
+    padding: 1rem;
+}
+
+.login-box {
+    background-color: #fff;
+    padding: 2rem;
+    border-radius: 5px;
+    box-shadow: 0 2px 15px rgba(0,0,0,0.1);
+}
+
+.login-box h1 {
+    text-align: center;
+    margin-bottom: 2rem;
+    color: #3498db;
+}
+
+.form-group {
+    margin-bottom: 1.5rem;
+}
+
+label {
+    display: block;
+    margin-bottom: 0.5rem;
+    font-weight: bold;
+}
+
+input[type="text"],
+input[type="password"] {
+    width: 100%;
+    padding: 0.8rem;
+    border: 1px solid #ddd;
+    border-radius: 4px;
+    font-size: 1rem;
+    transition: border-color 0.3s;
+}
+
+input[type="text"]:focus,
+input[type="password"]:focus {
+    border-color: #3498db;
+    outline: none;
+    box-shadow: 0 0 0 2px rgba(52, 152, 219, 0.2);
+}
+
+.btn-login {
+    background-color: #3498db;
+    color: #fff;
+    border: none;
+    padding: 0.8rem;
+    width: 100%;
+    font-size: 1rem;
+    border-radius: 4px;
+    cursor: pointer;
+    transition: background-color 0.3s;
+}
+
+.btn-login:hover {
+    background-color: #2980b9;
+}
+
+.error-message {
+    color: #e74c3c;
+    font-size: 0.85rem;
+    margin-top: 5px;
+    display: block;
+}
+
+.form-message {
+    text-align: center;
+    margin-top: 1rem;
+    font-weight: bold;
+}
+
+.form-message.error {
+    color: #e74c3c;
+}
+
+.form-message.success {
+    color: #2ecc71;
+}
+
+/* 响应式设计 */
+@media screen and (max-width: 768px) {
+    header h1 {
+        font-size: 1.5rem;
+    }
+    
+    nav ul {
+        flex-direction: column;
+    }
+    
+    nav ul li {
+        margin-right: 0;
+        margin-bottom: 0.5rem;
+    }
+}
+
+@media screen and (max-width: 480px) {
+    .login-container {
+        padding: 0.5rem;
+    }
+    
+    .login-box {
+        padding: 1.5rem;
+    }
+    
+    .login-box h1 {
+        font-size: 1.5rem;
+    }
+}
\ No newline at end of file