body {
    font-family: Arial, sans-serif;
    background-color: #f4f4f4;
    margin: 0;
    padding: 0;
    color: #333;
}

.container {
    max-width: 800px;
    margin: auto;
    padding: 20px;
}

h1 {
    text-align: center;
    color: #4A90E2;
}

.rule {
    margin-bottom: 20px;
    border: 1px solid #ddd;
    border-radius: 5px;
    background-color: #fff;
}

.rule-header {
    background-color: #4A90E2;
    color: #fff;
    padding: 15px;
    width: 100%;
    border: none;
    text-align: left;
    font-size: 18px;
    cursor: pointer;
}

.rule-header:focus {
    outline: none;
}

.rule-brief {
    padding: 15px;
    background-color: #eaf4ff;
    border-top: 1px solid #ddd;
    font-size: 16px;
}

.rule-content {
    padding: 15px;
    display: none;
    border-top: 1px solid #ddd;
}

.rule-content pre {
    background-color: #f4f4f4;
    padding: 10px;
    border-radius: 5px;
    overflow-x: auto;
}

@media (max-width: 600px) {
    .rule-header {
        font-size: 16px;
    }

    .rule-brief {
        font-size: 14px;
    }

    .rule-content pre {
        font-size: 14px;
    }
}
footer {
    text-align: center;
    padding: 5px;
    color: #000;
}