Floating astral island with mostly ...

Floating astral island with mostly flat dark purple surface. Central constellation dome with glowing star map ceiling. Floating geometric shapes (tetrahedrons, cubes) made of stained glass around the edges. Small portal archway with swirling effects (purple/blue glass). Scattered starlight pools (glowstone under cyan water) on the ground. Flat open spaces between structures for combat. Detailed with purpur, end stone, magenta/cyan glass, sea lanterns, and starfield particles. No fixed spawns. Void below with deep space nebula backdrop.