After a whirlwind The Girl With the Dragon Tattoo world premiere tour, not to mention this past award season's countless red carpet affairs, Rooney Mara has officially sealed her status as a serious A-lister. And if her penchant for edgy Nina Ricci cutout gowns and slick Dion Lee LBDs are any indication, we know this actress is certainly one to watch. Today, Rooney celebrates her 27th birthday and to fête the occasion, we've honed in on her ultradynamic style résumé. From long, girl-next-door locks and pretty premiere dresses to a sharp, sophisticated coif and turns in chic Givenchy and Prabal Gurung couture, Miss Mara may just be as fascinating to watch off screen as she is on. Click through to see her fashionable evolution now.