Create a premium vertical product advertising poster for a fictional luxury hair oil brand "GOLDEN THREAD". Preserve bold modern product-poster logic: single hero bottle centered, fully saturated monochrome background, oversized headline behind the bottle, vertical side label, short bottom descriptor. COMPOSITION: a sleek amber glass bottle with a dropper cap slightly below center on a seamless warm golden background, a single luminous oil droplet suspended mid-air, scattered dried flowers (rose, jasmine) and a crisp diagonal shadow. TYPOGRAPHY: large bold white stacked headline "SILK / RADIANCE" behind the bottle; slim vertical left label "ARGAN + JASMINE OIL"; bottom line "NOURISHED, LUMINOUS, STRONG." LIGHTING: strong clean directional light upper-left, glossy bottle and droplet highlights, elegant shadow. STYLE: Cannes-level luxury product advertising, ultra-real. NEGATIVE: cheap label, cluttered layout, plastic texture, muddy background, weak shadow, unreadable text, watermark. 8k.