Costume designer Jacqueline Demeterio opens up about dressing Anne Hathaway’s character for Coachella, the symbolism behind that red suit, and the French style icon who inspired her aesthetic.

In The Idea of You, Anne Hathaway’s charming May-December romance with Nicholas Galitzine might be the main event, but her style is a close second. And there is nothing matronly about her wardrobe.

Based on the eponymous book by Robinne Lee, Anne plays Solène, a 40-year-old Silver Lake divorcee and art gallery owner with a teen daughter, who falls for Hayes (Galitzine), the 24-year-old lead singer of the boy band August Moon, after a chance meeting at Coachella. From the get-go, Solène is inherently chic with her blunt bangs, vintage denim, and velvet blazers.

As her relationship with Hayes heats up, her looks become edgier, and at times, a vehicle for her insecurities about their age difference. But there’s never a moment where Solène doesn’t look like a quintessential “cool mom.”(After all, she takes her teen daughter and her friends to Coachella to meet their favorite boy band. What can be cooler than that?)

Ahead of the release of The Idea of You, now streaming on Prime Video, ELLE.com caught up with costume designer Jacqueline Demeterio—who is responsible for Solène’s enviable style. She and Hathaway had collaborated twice before, on the 2015 film The Intern and Apple TV+ series WeCrashed. A few months after working on the latter, when Hathaway shared plans for The Idea of You, Demetrio was “100 percent down.” “It sounded so in my wheelhouse and her wheelhouse, and we’ve worked so well together and we’d love to collaborate,” she says.

Here, Demetrio tells us about working with Hathaway, the designers she gravitated toward, and the French muse who inspired Solène’s style.

I didn’t read the book at first because I didn’t want to get confused [since] I knew we were doing something a little bit different. I didn’t want to have that influence me too much. But then Anne suggested [I] read the book, so I read the book. But the mom in the book is a little more high-end, luxury fashion—she’s wealthier. Michael Showalter wanted the film to be a bit more down to earth and a little bit more grounded with the characters. At first, I thought it was gonna be a little more [of a] glossy look. Once I got the revision [of the script?], [it’s clear] she’s a mother from Silver Lake, but she’s a cool mom. She’s beautiful, she owns a gallery, she’s hip. So we wanted her [to] have that essence but also not be too out of reach. I didn’t want her to be head-to-toe in new stuff all the time. Like, we had a great pair of jeans that we utilized. We had the same shoes and some of the same bags, but everything was cool.

Was there anyone you had in mind as a muse for Solène?

One of my inspirations was Jane Birkin. The Parisian street style and bohemian feel were what the inspiration was. Then, of course, adding that to her living in Silver Lake, it fell right into place. Anne pulls that off so effortlessly—so cool and chic. It just worked.