Create a vertical 9:16 minimalist isometric 3D illustration of a tiny, extremely peaceful stress-relief oasis hidden inside an old beige desktop computer tower. The computer case should feel like a late-1990s or early-2000s office ATX tower. Inside the cold technology shell, build a Japanese dry landscape garden with carefully raked sand, small stones, moss, a few minimal garden details, and a quiet meditative mood. Give the scene a light 3D texture with a subtle plastic model feel, like a delicate tabletop diorama and a warm secret hidden under a rigid computer exterior. Emphasize the visual and emotional contrast between work pressure and restraint outside, and inner calm and spiritual freedom inside. Use clean isometric composition, soft warm light, refined miniature detail, and no readable text, logos, brand names, or watermark.