Jason Merritt/Getty Images For DETAILS Magazine

WHAT SHE WORE Olivia Wilde was on hand to celebrate Ryan Reynolds's Details cover in a black and white dress and satin Sergio Rossi pumps.

WHY WE LOVE IT You don't have to bare skin wear cutouts! The actress worked one of this season's sexiest trends in a layered sheath.

CELEBRITY: Olivia Wilde

DESIGNER: Sergio Rossi

TREND: Black

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Olivia Wilde

Olivia Wilde in Sergio Rossi