body {
        font-family: Arial, sans-serif;
        line-height: 1.6;
        max-width: 800px;
        margin: auto;
        padding: 20px;
        background: #ffffff;
        color: #000000;
        transition: background 0.3s, color 0.3s;
    }
    body.dark {
        background: #1e1e1e;
        color: #f0f0f0;
    }
    h1 {
        text-align: center;
        color: inherit;
    }
    ol {
        background: rgba(248, 249, 250, 0.8);
        padding: 20px;
        border-radius: 8px;
        transition: background 0.3s;
    }
    body.dark ol {
        background: rgba(40, 40, 40, 0.8);
    }
    li {
        margin: 8px 0;
    }
    a {
        text-decoration: none;
        color: #0077cc;
    }
    body.dark a {
        color: #66aaff;
    }
    a:hover {
        text-decoration: underline;
    }
    .toggle-btn {
        display: block;
        margin: 10px auto 20px;
        padding: 8px 16px;
        cursor: pointer;
        background: #0077cc;
        color: white;
        border: none;
        border-radius: 5px;
        font-size: 14px;
        transition: background 0.3s;
    }
    .toggle-btn:hover {
        background: #005fa3;
    }