/* 全局样式 */
    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }

    body {
        font-family: 'Poppins', sans-serif;
        line-height: 1.6;
        color: #333;
        background: linear-gradient(135deg, #a1c4fd, #c2e9fb);
        animation: backgroundShift 15s linear infinite;
        padding: 20px;
    }

    @keyframes backgroundShift {
        0% { background-position: 0% 50%; }
        50% { background-position: 100% 50%; }
        100% { background-position: 0% 50%; }
    }

    header {
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        background: rgba(255, 255, 255, 0.8);
        box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
        z-index: 1000;
    }

    .navbar {
        display: flex;
        justify-content: space-between;
        align-items: center;
        padding: 15px 30px;
    }

    .navbar a {
        text-decoration: none;
        color: #333;
        margin: 0 10px;
        font-weight: 500;
        transition: color 0.3s ease;
    }

    .navbar a:hover {
        color: #1e90ff;
    }

    main {
        max-width: 1200px;
        margin: 100px auto 50px auto;
        padding: 20px;
        background: rgba(255, 255, 255, 0.9);
        border-radius: 10px;
        box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    }

    h1, h2, h3 {
        color: #1e90ff;
        margin-bottom: 20px;
    }

    h1 {
        font-size: 2.5em;
        text-align: center;
    }

    h2 {
        font-size: 2em;
        margin-top: 40px;
    }

    h3 {
        font-size: 1.5em;
        margin-top: 30px;
    }

    p {
        margin-bottom: 20px;
        text-align: justify;
    }

    pre {
        background: #f4f4f4;
        padding: 15px;
        border-radius: 5px;
        overflow: auto;
        margin-bottom: 20px;
    }

    code {
        font-family: 'Courier New', Courier, monospace;
        color: #d63384;
    }

    table {
        width: 100%;
        border-collapse: collapse;
        margin-bottom: 20px;
    }

    table, th, td {
        border: 1px solid #ddd;
    }

    th, td {
        padding: 12px;
        text-align: left;
    }

    th {
        background-color: #1e90ff;
        color: white;
    }

    .card-grid {
        display: grid;
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: 20px;
        margin-top: 40px;
    }

    .card {
        background: linear-gradient(135deg, #f6d365 0%, #fda085 100%);
        border-radius: 10px;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        overflow: hidden;
        transition: transform 0.3s ease, box-shadow 0.3s ease;
    }

    .card:hover {
        transform: scale(1.05);
        box-shadow: 0 12px 16px rgba(0, 0, 0, 0.2);
    }

    .card img {
        width: 100%;
        height: 200px;
        object-fit: cover;
    }

    .card-content {
        padding: 15px;
    }

    .card-title {
        font-size: 1.2em;
        margin-bottom: 10px;
        color: #fff;
    }

    .card-description {
        font-size: 0.95em;
        margin-bottom: 15px;
        color: #fff;
        height: 60px;
        overflow: hidden;
    }

    .card button {
        background-color: #ff7e5f;
        color: white;
        border: none;
        padding: 10px 15px;
        border-radius: 50px;
        cursor: pointer;
        transition: background-color 0.3s ease;
    }

    .card button:hover {
        background-color: #feb47b;
    }

    footer {
        text-align: center;
        padding: 20px;
        background: rgba(255, 255, 255, 0.8);
        border-radius: 10px;
        box-shadow: 0 -2px 4px rgba(0, 0, 0, 0.1);
        margin-top: 50px;
    }

    footer a {
        text-decoration: none;
        color: #333;
        margin: 0 10px;
        transition: color 0.3s ease;
    }

    footer a:hover {
        color: #1e90ff;
    }

    /* 响应式设计 */
    @media (max-width: 1440px) {
        main {
            max-width: 1100px;
        }
    }

    @media (max-width: 1200px) {
        main {
            max-width: 1000px;
        }
    }

    @media (max-width: 1024px) {
        .navbar {
            flex-direction: column;
        }

        .navbar a {
            margin: 5px 0;
        }
    }

    @media (max-width: 768px) {
        .card img {
            height: 150px;
        }

        h1 {
            font-size: 2em;
        }

        h2 {
            font-size: 1.8em;
        }

        h3 {
            font-size: 1.3em;
        }
    }

    @media (max-width: 480px) {
        main {
            padding: 10px;
        }

        .card img {
            height: 120px;
        }

        .card-content {
            padding: 10px;
        }

        .card-description {
            height: 50px;
        }
    }

    @media (max-width: 320px) {
        h1 {
            font-size: 1.8em;
        }

        h2 {
            font-size: 1.5em;
        }

        h3 {
            font-size: 1.1em;
        }

        .card img {
            height: 100px;
        }

        .card-description {
            height: 40px;
        }

        .navbar {
            padding: 10px 20px;
        }
    }