Blue Penguin Classics hardcover mystery with owl bookmark

I lost my blue Penguin Classics hardcover mystery edition yesterday around 3pm, outside the South Bend Public Library on Main Street near the fountain. It's a sturdy 320-page book with a slightly dented spine and a coffee ring on the bottom edge. I always use a small silver owl bookmark tucked between pages, and it's a feature the book-reading friends would notice. It was a gift from my mom and it means a lot to me—comfort during long bus rides home. If anyone found it, please reach out; I really need it back.