Seamless dark glass texture, tileable, no edges, no borders. Slightly dirty glass surface with subtle dust, smudges, faint streaks and grime. Dark tone, low light transmission, minimal transparency. Smooth glossy surface, very low roughness, realistic subtle reflections. No cracks, no damage, no strong patterns. Neutral, evenly distributed dirt, suitable for repetition. Photorealistic material texture, physically based rendering reference. Straight-on view, flat texture, uniform lighting, no perspective. High realism, not illustration, not stylized.