This arty, wispy tale of the fraught near-future affair between a sensitive white man and his newly sentient operating system will not be for everyone, but everyone will have to hear about it nonetheless. Is it not, therefore, the movie of our cultural moment? Confoundingly, it's also very well done. The filmmaker is of course Spike Jonze, who warmed up for this a few years ago with his short film/vodka commercial I'm Here, about a mild-mannered robot in a self-destructive relationship. The whole point of Her is the anxious question of conceptual sustainability, be it philosophical or technological or dramatic; beneath Jonze's rueful whimsy and bittersweet soft-focus love story lurks the prospect of a dystopian sci-fi thriller — the mindset in which being outgrown by your initially servile mate seems like an annihilation worse than nuclear doomsday. Inescapably, it's a manchild's perspective, but that hint of stunted development works to a poignant advantage thanks largely to the precision and total emotional availability of this movie's stars. Joaquin Phoenix goes all in as the guy, and it seems like a sly maneuver when Scarlett Johansson, who's spent most of her young adult life being ogled for her appearance, shows up in voice only as the OS. (That Samantha Morton first recorded the part but then was replaced by Johansson only reaffirms the crucial narrative seamlessness here.) With memorable supporting turns from Amy Adams, Rooney Mara, Olivia Wilde, and Portia Doubleday, Jonze's shiny someday-L.A. also is a few parts Shanghai and an apt setting in which to stage his existential angst about how gadgets, like movies, offer dangerous and dazzling simulations of intimacy.