Once synonymous with flimsy T-shirts, summer-movie fashion tie-ins are going swanky. Fifth Avenue retailer Henri Bendel is launching a clothing line ''inspired'' by Halle Berry's Catwoman to coincide with the film's July release. And that's just scratching the surface: Trendy L.A. boutique Kitson offers a collection (with hoodies and handbags) starring Archie gal pals Betty and Veronica, tied to Miramax's planned movie inspired by the comic. And designer Thomas Pink fetes 40 years of The Pink Panther with a line of shirts and ties, and cuff links (Steve Martin will play bumbling Inspector Clouseau in '05). ''Instead of taking a mass-market in-and-out approach,'' says MGM VP of worldwide marketing Trish Halamandaris of the Panther tie-ins, ''[we're targeting] the consumer who will remember this franchise.''