Written and directed by Spike Jonze. Starring Joaquin Phoenix, Scarlett Johansson, and Amy Adams. 120 minutes. Rated R.The terrible reality of modern life is that even beautiful young people on a first date can't go a whole evening without checking their phones. Just allowing the present to happen has become increasingly foreign. That's the idea Spike Jonze is scratching at in his futuristic romance Her, in which Joaquin Phoenix plays Theodore, an about-to-be-divorced Los Angeles writer who falls in love with an operating system, one designed not only to run his laptop and devices but to help him get through life; it intuits and meets his every need. That setup might sound weirder than it is: The voice of this OS — she calls herself Samantha — is Scarlett Johansson's, and if you heard it, shimmering into your brain through an earpiece all day, you'd fall in love with it too. That voice is very real. The complication is that it belongs not to an actual woman but to an algorithmic construct. In case you haven't guessed, Theodore is using technology to avoid the pain of real human connection. That's the problem with Her too: Jonze is so entranced with his central conceit that he can barely move beyond it. This is a movie about a benumbed person that itself feels chloroformed and zonked out, even in those moments when Jonze is clearly striving for depth of feeling. Its metaphors are more obvious than the bricks that cruel mouse Ignatz used to hurl at poor, lovelorn Krazy Kat and yet not nearly as direct. Instead of just being desperately heartfelt, Her keeps reminding us — through cinematographer Hoyte Van Hoytema's somber-droll camera work, through Phoenix's artfully slumped shoulders — how desperately heartfelt it is.