YA science fiction book cover with split-level composition. Upper third: completely black starless void, flat darkness with no texture or light. Middle section: willowy 5'7" teenage girl with long auburn hair, light pink matte non-iridescent skin, pale blue-gray eyes, broad shoulders, holding black acoustic guitar embedded with tiny twinkling LED stars, figure has shifting prismatic edges suggesting fluidity, positioned as bridge between upper and lower worlds. Lower third: cross-section cutaway view into mountain showing hidden underground community with warm golden amber lighting, carved tunnels and chambers, small figures of people with varying skin tones from dull to iridescent, ancient texts and artifacts glowing softly in archive rooms. Background: three cylindrical fusion reactor towers emitting controlled blue-white energy beams that don't reach the starless sky above. Art style: detailed fantasy illustration, rich contrast between oppressive darkness above and warm hidden world below, emphasis on mystery and discovery, cinematic lighting, book cover composition with space for title text in the dark sky area. See more