Dark and mysterious background with graffiti-style text "GBrain". The letters should be in bold, dark gray tones against the black backdrop, creating an atmosphere of intrigue. There is no mockup or frame around them. It's designed to convey hidden information or secrets within its design. This wallpaper would work well on mobile phones as it embodies street art aesthetics while also being suitable for use as an app background or screen, capturing attention in the style of graffiti art. --ar 9:16