plain sailing
noun
mass noun［usu. with negative］
- used to describe a process or activity which goes well and is easy and uncomplicated一帆风顺：
teambuilding was not all plain sailing.
建立队伍并不总是一帆风顺的。
词源
mid 18th cent.: probably a popular use of plane sailing, denoting the practice of determining a ship's position on the theory that it is moving on a plane.