Create a detailed, elegant book cover background for an adult coloring book

Create a detailed, elegant book cover background for an adult coloring book. The theme is floral, featuring a variety of intricate flowers in soft, pastel colors. The design should include delicate line art that is both inviting and relaxing, appealing to adults. The background should have a subtle gradient or texture that complements the floral design, ensuring that the flowers stand out. The overall aesthetic should be calming, sophisticated, and suitable for a mature audience.