Create a refreshing premium drink advertising poster for a fictional café "PETAL". FORMAT: 4:5 vertical, soft botanical layout. SUBJECT: a tall glass of blush-pink lavender lemonade with crushed ice, dried lavender sprigs and lemon wheel, a delicate purple splash frozen mid-air. BACKGROUND: soft lilac-to-blush gradient with botanical texture. LIGHTING: crisp fresh highlights, glistening ice, gentle floral glow. TYPOGRAPHY: elegant minimal logo "PETAL" top-center, tiny tagline "Sip something beautiful" bottom. FINISH: 8k, hyper-realistic, dreamy finish.