/* 全局样式 */
    body {
        margin: 0;
        padding: 0;
        font-family: 'Open Sans', sans-serif;
        background: linear-gradient(135deg, #0f0c29, #302b63, #24243e);
        color: #ffffff;
        transition: background 0.5s ease;
    }

    /* 头部样式 */
    header {
        padding: 20px;
        text-align: center;
        background: rgba(0, 0, 0, 0.5);
    }

    header h1 {
        font-family: 'Poppins', sans-serif;
        font-size: 2.5em;
        color: #00ff99;
        margin: 0;
    }

    /* 主体网格布局 */
    .main {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
        gap: 20px;
        padding: 40px;
    }

    /* 卡片样式 */
    .card {
        background-color: #121212;
        border-radius: 8px;
        box-shadow: 0 4px 6px rgba(0, 0, 0, 0.2);
        transition: transform 0.3s ease-in-out, box-shadow 0.3s;
        position: relative;
        overflow: hidden;
    }

    .card:hover {
        transform: translateY(-5px);
        box-shadow: 0 8px 12px rgba(0, 0, 0, 0.3);
    }

    .card-icon {
        font-size: 2em;
        margin: 20px;
        color: #00ff99;
    }

    .card-title {
        font-family: 'Poppins', sans-serif;
        font-size: 1.5em;
        padding: 0 20px;
        color: #ffffff;
    }

    .card-description {
        padding: 0 20px;
        color: #cccccc;
        min-height: 60px;
    }

    .card-button {
        margin: 20px;
        padding: 10px 20px;
        background: #00ff99;
        color: #121212;
        border: none;
        border-radius: 4px;
        cursor: pointer;
        transition: background 0.3s;
        text-decoration: none;
        text-align: center;
        display: inline-block;
    }

    .card-button:hover {
        background: #00e68a;
    }

    /* 示例文章样式 */
    .sample-article {
        padding: 40px;
        background: rgba(0, 0, 0, 0.8);
        margin: 40px;
        border-radius: 8px;
    }

    .sample-article h2, .sample-article h3 {
        color: #00ff99;
        font-family: 'Poppins', sans-serif;
    }

    .sample-article p {
        color: #cccccc;
        line-height: 1.6;
    }

    .sample-article pre {
        background: #1e1e1e;
        padding: 10px;
        border-radius: 4px;
        overflow-x: auto;
    }

    .sample-article code {
        color: #ffcc00;
    }

    /* 表格样式 */
    .sample-article table {
        width: 100%;
        border-collapse: collapse;
        margin: 20px 0;
    }

    .sample-article th, .sample-article td {
        border: 1px solid #444;
        padding: 10px;
        text-align: left;
    }

    .sample-article th {
        background: #00ff99;
        color: #121212;
    }

    /* 响应式设计 */
    @media (max-width: 767px) {
        .main {
            padding: 20px;
        }
        header h1 {
            font-size: 1.8em;
        }
        .sample-article {
            padding: 20px;
            margin: 20px;
        }
    }

    @media (min-width: 768px) and (max-width: 1199px) {
        .main {
            padding: 30px;
        }
    }

    @media (min-width: 1200px) {
        .main {
            padding: 50px;
        }
    }

    /* 额外视觉效果 */
    body::before {
        content: "";
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center center;
        background-size: cover;
        opacity: 0.1;
        z-index: -1;
    }

    .decorative-image {
        width: 100%;
        height: auto;
        border-radius: 8px;
        margin-top: 20px;
    }