/*
        本CSS是响应式导航栏
        */

        * {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            text-decoration: none;
            list-style: none;
            font-family: 'Arial', sans-serif;
        }

        .navbar {
            background-color: #2c3e50;
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            z-index: 999;
            box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
        }

        .container_css {
            width: 100%;
            max-width: 1200px;
            margin: 0 auto;
            padding: 0 20px;
        }

        .navbar .container_css {
            display: flex;
            justify-content: space-between;
            align-items: center;
            height: 60px;
        }

        .logo {
            color: #fff;
            font-size: 3rem;
            font-weight: 700;
        }

        .nav-menu {
            display: flex;
            gap: 30px;
        }

        .nav-link {
            color: #fff;
            font-size: 1.5rem;
            font-weight: 500;
            transition: color 0.3s ease;
        }

        .nav-link.active,
        .nav-link:hover {
            color: #3498db;
        }

        .hamburger-btn {
            display: none;
            background: transparent;
            border: none;
            color: #fff;
            font-size: 1.5rem;
            cursor: pointer;
        }

        @media (max-width: 768px) {
            .hamburger-btn {
                display: block;
            }

            .nav-menu {
                position: fixed;
                top: 60px;
                left: -100%;
                width: 100%;
                height: calc(100vh - 60px);
                background-color: #34495e;
                flex-direction: column;
                gap: 0;
                transition: left 0.3s ease;
                padding: 20px 0;
            }

            .nav-item {
                width: 100%;
                padding: 15px 20px;
                border-bottom: 1px solid rgba(255, 255, 255, 0.1);
            }

            .nav-menu.show {
                left: 0;
            }

            .hamburger-btn.close i {
                content: "\f00d";
                font-family: "Font Awesome 6 Free";
                font-weight: 900;
            }
        }

        body {
            padding-top: 60px;
            background-color: #f5f5f5;
            min-height: 100vh;
        }

        .main-content {
            padding: 20px;
            text-align: center;
        }

        .main-content h1 {
            color: #2c3e50;
            margin-bottom: 20px;
        }

        .main-content p {
            color: #666;
            font-size: 1.1rem;
        }