body {
            font-family: 'Roboto', sans-serif;
            font-size: 18px;
            line-height: 1.8;
            margin: 0;
            padding: 0;
            background-color: #f3f4f6;
            color: #333;
        }
        header {
            background-color: #2c3e50;
            color: white;
            padding: 1.5rem 0;
            text-align: center;
        }
        main {
            padding: 1.5rem 2rem;
            max-width: 800px;
            margin: auto;
        }
        h1 {
            color: #f5f5f5;
        }

        h2 {
            color: #2c3e50;
        }
        p {
            margin: 1.2rem 0;
        }
        ul {
            list-style: none;
            padding: 0;
        }
        ul li {
            background: #ecf0f1;
            margin: 0.6rem 0;
            padding: 0.6rem;
            border-left: 4px solid #27ae60;
        }
        .tips {
            background-color: #e9f7ef;
            border: 1px solid #27ae60;
            padding: 1.2rem;
            margin-top: 2rem;
        }
        .tips ul li {
            background: none;
            padding: 0;
            border: none;
        }
        a {
            color: #2980b9;
            text-decoration: none;
        }
        a:hover {
            text-decoration: underline;
        }
        img {
            display: block;
            max-width: 100%;
            height: auto;
            margin: 2rem auto;
            border-radius: 8px;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
        }
        @media (max-width: 600px) {
            main {
                padding: 1rem;
            }
        }