nav {
			background-color: #333;
			color: white;
			padding: 10px 0;
			text-align: center;
			position: fixed; /* 固定导航栏 */
			top: 0; /* 固定在页面顶部 */
			width: 100%; /* 宽度为100% */
			z-index: 1000; /* 确保导航栏在其他内容之上 */
		}
        /* 页面样式 */
        body {
            font-family: Arial, sans-serif;
            margin: 0;
            padding: 0;
            background-color: #f4f4f4;
            color: #333;
            scroll-behavior: smooth; /* 平滑滚动效果 */
        }

        header {
            background-color: #333;
            color: white;
            padding: 20px;
            text-align: center;
        }

        .welcome {
            text-align: center;
            padding: 50px 20px;
            background-color: #4CAF50;
            color: white;
            font-size: 24px;
        }

        nav {
            background-color: #333;
            color: white;
            padding: 10px 0;
            text-align: center;
        }

        nav ul {
            list-style: none;
            padding: 0;
        }

        nav ul li {
            display: inline;
            margin: 0 20px;
        }

        nav ul li a {
            color: white;
            text-decoration: none;
            font-size: 18px;
        }

        main {
            padding: 20px;
        }

        section {
            margin-bottom: 20px;
        }

        .profile-img {
            width: 150px;
            height: 150px;
            border-radius: 50%;
            margin-bottom: 10px;
        }

        footer {
            background-color: #333;
            color: white;
            text-align: center;
            padding: 10px 20px;
            position: fixed;
            width: 100%;
            bottom: 0;
        }