{
    "code": 400,
    "msg": "请指定 action 参数",
    "available_actions": {
        "toplists": "获取所有榜单列表",
        "detail": "获取单个榜单详情（需传入 type 或 id）"
    },
    "detail_example": {
        "?action=detail&type=hot": "获取热歌榜",
        "?action=detail&id=3778678&limit=10": "通过ID获取指定榜单"
    }
}