Create a calm premium advertising poster for a fictional organic tea brand "ZEN LEAF". FORMAT: 4:5 vertical, minimalist wellness layout. SUBJECT: a delicate glass teapot of golden herbal tea beside a single porcelain cup, fresh green leaves and a curl of gentle steam. BACKGROUND: soft sage-to-cream gradient with subtle rice-paper texture, tranquil empty space. LIGHTING: soft diffused natural morning light, delicate reflections, serene mood. TYPOGRAPHY: refined thin serif brand name "ZEN LEAF" centered top, tiny tagline "Breathe. Sip. Restore." at the bottom. FINISH: 8k, photorealistic, calm premium wellness aesthetic.