body {
    font-family: Arial, sans-serif;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
}

header, footer {
    width: 100%;
    background-color: #333;
    color: white;
    text-align: center;
    padding: 10px 0;
}

header h1, footer p {
    margin: 0;
}

#game-rules {
    width: 300px; /* 根据需要调整宽度 */
    height: 200px; /* 根据需要调整高度 */
    overflow-y: auto; /* 垂直方向滚动条 */
    overflow-x: hidden; /* 水平方向隐藏滚动条 */
    padding: 10px;
    box-sizing: border-box;
    border: 1px solid #ccc; /* 可选：添加边框 */
    background-color: #f9f9f9; /* 可选：设置背景色 */
    margin-top: 20px;
}

#winning-number {
    margin-top: 20px;
    padding: 10px;
    font-size: 24px;
    cursor: pointer;
    border: 1px solid #ccc;
    display: inline-block;
}

.grid-container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    margin-top: 20px;
}

.grid-item {
    width: 70px;
    height: 70px;
    background-color: #e0e0e0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    cursor: pointer;
    border: 1px solid #ccc;
}

#replay-button {
    margin-top: 20px;
    padding: 10px 20px;
    font-size: 18px;
    cursor: pointer;
}