Abstract Cinematic Gradient Background with Warm and Cool Tones

abstract cinematic gradient background, soft diagonal band of warm red, orange and golden yellow light sweeping from lower left toward upper right, fading into cool cyan and deep blue on the right, surrounded by rich black shadowed corners, smooth atmospheric blur, subtle film grain texture, low contrast edges, dark moody vignette, minimalist color field photography, out-of-focus light leak effect, no text, no watermark