Epic Fantasy Mecha Light Novel Cover

Prompt

Create a dramatic Japanese light-novel cover illustration for a fantasy mecha isekai story. Vertical poster composition with a huge heroic humanoid robot dominating the center foreground, viewed from a slightly low angle to make it monumental. The robot is sleek and ornate, with white and silver armor, rich gold trim, glowing cyan energy lines, a radiant emerald-green core in the chest, a crown-like crest on the helmet, and a long royal blue cape with gold edging. Behind its back spread multiple crystalline energy wings, about 8 large translucent green shards fanning out symmetrically like luminous blades. In its left hand it holds a long fantasy-tech spear with a blue glowing blade and gold mechanical detailing. At the robot’s feet are 2 human characters: on the left, a red-haired fantasy heroine with very long braided hair, leather-and-fabric adventurer clothing, and a determined expression, looking up at the robot; on the right, a young male protagonist with short dark hair in a fantasy tunic and cloak, reaching one hand up toward the giant machine in awe and urgency, seen mostly from behind. The setting is an epic ruined sci-fi fantasy world with towering gothic spires, broken city structures, drifting smoke, dramatic clouds, and a sky filled with stars, planets, streaks of lightning, and 8 small flying warships scattered in the distance. Highly polished anime key visual style, ultra-detailed, cinematic lighting, intense contrast, blue-green-gold color palette, heroic atmosphere, intricate mechanical rendering, fantasy worldbuilding, premium game or novel cover finish. Add large Japanese title typography at the top: 《{argument name="tagline text" default="本格異世界SFロボット戦記"}》 above a massive metallic logo reading {argument name="series title" default="ASTRAIA"}, with a smaller Japanese subtitle line beneath it. Add a large dramatic Japanese catchphrase at the bottom in glowing white and gold text over 2 lines: {argument name="bottom catchphrase" default="乗って！ユウキ！ その叫びが、世界の運命を決めた！"}. Keep the overall design dense, premium, and readable as a commercial cover, with the central robot as the unmistakable focal point.