:root {
        --primary-color: #0074D9; /* 深蓝色 */
        --accent-color: #FFA500; /* 金色 */
        --text-color: #FFFFFF;   /* 白色文字 */
        --background-color: #1E1E1E; /* 黑色背景 */
        --secondary-color: #343A40; /* 辅助深色 */
        --hover-color: #FF8C00; /* 悬停渐变色 */
        --font-family: 'Roboto', sans-serif;
    }

    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
    }

    body {
        font-family: var(--font-family);
        font-size: 16px;
        line-height: 1.6;
        color: var(--text-color);
        background: linear-gradient(135deg, #0f2027, #203a43, #2c5364);
        overflow-x: hidden;
    }

    header {
        background: var(--secondary-color);
        padding: 20px;
        text-align: center;
        position: relative;
        overflow: hidden;
    }

    header h1 {
        font-size: 2.5rem;
        color: var(--accent-color);
        animation: fadeIn 2s ease-in-out;
    }

    nav {
        margin-top: 10px;
    }

    nav a {
        color: var(--text-color);
        margin: 0 15px;
        text-decoration: none;
        font-size: 1rem;
        transition: color 0.3s ease;
    }

    nav a:hover {
        color: var(--accent-color);
    }

    .particle-background {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: radial-gradient(circle, rgba(255,87,34,0.3), transparent);
        animation: aurora-move 15s linear infinite;
        z-index: -1;
    }

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

    @keyframes fadeIn {
        from { opacity: 0; }
        to { opacity: 1; }
    }

    main {
        padding: 40px 20px;
        max-width: 1200px;
        margin: 0 auto;
    }

    .section {
        margin-bottom: 40px;
    }

    .section h2 {
        font-size: 2rem;
        color: var(--accent-color);
        margin-bottom: 20px;
        position: relative;
        display: inline-block;
    }

    .section p {
        font-size: 1rem;
        color: var(--text-color);
        margin-bottom: 20px;
    }

    .grid-container {
        display: grid;
        grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
        gap: 20px;
    }

    .grid-item {
        background: var(--secondary-color);
        padding: 20px;
        border-radius: 10px;
        position: relative;
        overflow: hidden;
        transition: transform 0.3s ease, background 0.3s ease;
    }

    .grid-item:hover {
        transform: translateY(-10px);
        background: var(--accent-color);
    }

    .grid-item img {
        width: 100%;
        height: auto;
        border-radius: 8px;
        margin-bottom: 15px;
    }

    .grid-item h3 {
        font-size: 1.5rem;
        margin-bottom: 10px;
    }

    .grid-item p {
        font-size: 0.95rem;
        line-height: 1.4;
    }

    .button {
        display: inline-block;
        background-color: var(--accent-color);
        color: var(--text-color);
        padding: 10px 20px;
        border: none;
        border-radius: 5px;
        text-decoration: none;
        transition: transform 0.3s ease, background-color 0.3s ease;
    }

    .button:hover {
        transform: scale(1.1);
        background-color: var(--hover-color);
    }

    footer {
        background: var(--secondary-color);
        padding: 20px;
        text-align: center;
        color: var(--text-color);
    }

    pre {
        background: #2c5364;
        padding: 15px;
        border-radius: 8px;
        overflow-x: auto;
        font-size: 0.9rem;
    }

    code {
        color: #ffcc00;
        font-family: 'Courier New', Courier, monospace;
    }

    .example-article {
        background: var(--secondary-color);
        padding: 30px;
        border-radius: 10px;
        margin-top: 40px;
    }

    .example-article h2, 
    .example-article h3 {
        color: var(--accent-color);
    }

    .example-article p {
        margin-bottom: 15px;
    }

    .recommendation-container {
        display: flex;
        flex-wrap: wrap;
        gap: 20px;
    }

    .recommendation-card {
        background: var(--primary-color);
        padding: 15px;
        border-radius: 8px;
        flex: 1 1 calc(33.333% - 40px);
        transition: background 0.3s ease;
    }

    .recommendation-card h4 {
        margin-bottom: 10px;
        color: var(--accent-color);
    }

    .recommendation-card p {
        font-size: 0.9rem;
    }

    /* Responsive Styles */
    @media (max-width: 1440px) {
        header h1 {
            font-size: 2rem;
        }
    }

    @media (max-width: 1200px) {
        .grid-container {
            grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
        }
    }

    @media (max-width: 1024px) {
        main {
            padding: 30px 15px;
        }

        .recommendation-card {
            flex: 1 1 calc(50% - 40px);
        }
    }

    @media (max-width: 768px) {
        nav a {
            display: block;
            margin: 10px 0;
        }

        .recommendation-card {
            flex: 1 1 100%;
        }
    }

    @media (max-width: 480px) {
        header h1 {
            font-size: 1.5rem;
        }

        .button {
            padding: 8px 16px;
            font-size: 0.9rem;
        }
    }

    @media (max-width: 320px) {
        .section h2 {
            font-size: 1.5rem;
        }

        .grid-item h3 {
            font-size: 1.2rem;
        }
    }