realism: the realism in the film is mostly presented by the plot and how it relates to real world events such as WW2. the introduction sets the scene and tells us how so many people ended up in Casablanca which is factually correct.
tone: the tone of the film is mostly light-hearted and romantic and presents a sort of escapism for the audience who’s lives would have been affected by the war at this time
film noir: the film uses a film noir style as it uses lighting that would accommodate a black and whit movie. for example uses bright lighting for lighter scenes and darker lighting for more sadder scenes