:root {
        --white-bg: #ffffff;
        --light-bg: #f5f7fa;
        --code-bg: #1a1a2e;
        --code-text: #ffffff;
        --text-color: #1e293b;
        --highlight-color: #4361ee;
        --secondary-color: #3f37c9;
        --gray-text: #64748b;
        --border-color: #e2e8f0;
        --card-bg: #ffffff;
        --section-title: #e63946;
        --card-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
        --header-gradient: linear-gradient(135deg, #4361ee, #3a0ca3);
    }

    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
        font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
            Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
    }

    body {
        background-color: var(--light-bg);
        color: var(--text-color);
        line-height: 1.6;
    }

    main {
        max-width: 1200px;
        margin: 0 auto;
        padding: 2rem 1rem;
    }

    .header-container {
        background-image: var(--header-gradient);
        padding: 2.5rem 1rem;
        border-radius: 10px;
        margin-bottom: 1.5rem;
        text-align: center;
        box-shadow: var(--card-shadow);
    }

    .title {
        color: white;
        margin-bottom: 0.5rem;
        font-size: 2.5rem;
        font-weight: 700;
    }

    .subtitle {
        color: rgba(255, 255, 255, 0.9);
        margin-bottom: 0.3rem;
        font-size: 1rem;
        max-width: 700px;
        margin-left: auto;
        margin-right: auto;
    }

    .cards-container {
        display: grid;
        grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
        gap: 1.5rem;
    }

    .card {
        background-color: var(--card-bg);
        border-radius: 10px;
        overflow: hidden;
        box-shadow: var(--card-shadow);
        padding: 1rem;
        display: flex;
        flex-direction: column;
        transition: transform 0.3s ease, box-shadow 0.3s ease;
        cursor: default;
    }

    .card:hover {
        transform: translateY(-10px);
        box-shadow: 0 12px 24px rgba(0, 0, 0, 0.25);
        cursor: pointer;
    }

    .section-title {
        display: flex;
        align-items: center;
        gap: 0.5rem;
        color: var(--section-title);
        margin-bottom: 0.3rem;
        font-size: 1.5rem;
        font-weight: bold;
    }

    .topic-name {
        color: red;
        font-weight: bold;
        margin-top: 1rem;
        margin-bottom: 0.3rem;
        font-size: 1rem;
    }

    pre {
        background-color: var(--code-bg);
        color: var(--code-text);
        padding: 1rem;
        border-radius: 8px;
        overflow-x: auto;
        margin: 0.2rem 0 0 0;
        font-family: "Consolas", "Monaco", monospace;
        font-size: 0.9rem;
        line-height: 1.5;
        box-shadow: inset 0 1px 5px rgba(0, 0, 0, 0.2);
        white-space: pre-wrap;
        flex-grow: 1;
        user-select: text;
    }

    .footer {
        text-align: center;
        padding: 2rem 0;
        margin-top: 3rem;
        color: var(--gray-text);
        font-size: 0.9rem;
        border-top: 1px solid var(--border-color);
    }

    .social-icons-container {
        width: 100%;
        display: flex;
        justify-content: center;
        align-items: center;
        padding: 20px 0;
        background-color: #f0f8ff;
    }

    .social-icons {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        align-items: center;
        gap: 20px;
    }

    .social-icons a {
        color: inherit;
        text-decoration: none;
        transition: transform 0.3s ease, color 0.3s ease;
        display: flex;
        justify-content: center;
        align-items: center;
    }

    .social-icons a:hover {
        transform: translateY(-5px);
        opacity: 0.8;
    }

    .social-icons a i {
        font-size: 2rem;
    }

    @media (max-width: 576px) {
        .social-icons {
            gap: 15px;
        }

        .social-icons a i {
            font-size: 1.5rem;
        }
    }

    @media (max-width: 375px) {
        .social-icons {
            gap: 10px;
        }

        .social-icons a i {
            font-size: 1.25rem;
        }
    }