ぴったんこperfectly matching, totally agreeing, concurring, sticking to

風(かぜ)がぴったんこ止(と)まって暖(あたた)かくなった。

Concurrently as the wind stopped it became warm. (Happening at the same time or very close to each other)

師匠(ししょう)と弟子(でし)は息(いき)がぴったんこと合(あ)っています。

The master and the disciple are perfectly matching their breathing with each other.

窓(まど)が開(ひら)いていると寒(さむ)いので窓(まど)をぴったんこ閉(し)めました。

The window was open and it was cold, so I closed the window tightly.

寒(さむ)さに弱(よわ)い飼(か)い猫(ねこ)が僕(ぼく)の温(あたた)かい体(からだ)にぴったんこと寄(よ)り添(そ)っています。

My pet cat, which is weak to the cold, is sticking to my warm body perfectly.

大(だい)の酒好(さけず)きがぴったんこ酒(さけ)をやめるなんて、どんなきっかけがあったんだろう？

How could that alcohol lover suddenly quit drinking... What was the reason for it, I wonder?