I am trying to learn $p$-adic Hodge theory. I found some materials explaining main theorems (or aspects) of the theory. However, I could not find references which explaining how to use the theory. Especially, I would like to know geometric/arithmetic applications, if there are, of $p$-adic Hodge theory in number theory. Since I did not specify meaning of the words 'geometric/arithmetic', any reference would be appreciated.