Summer Morning Glory Poster

Create a vertical Chinese aesthetic summer poster in a soft watercolor / mineral-pigment print style. Canvas: portrait 2:3 ratio, warm ivory rice-paper background with ample negative space on the right. Composition: the left two-thirds are filled with winding morning glory vines rising diagonally from bottom left to upper left, with translucent green heart-shaped leaves, thin curling tendrils, pale stems, and a few unopened buds; the right third remains mostly blank for vertical typography. Include exactly 5 prominent morning glory blossoms: 1 large pale pink blossom in the upper-left center, 1 small light blue blossom near the upper center, 1 medium lavender-purple blossom in the middle, 1 large sky-blue blossom in the lower-left center, and 1 small pale pink-lavender blossom in the lower-right of the vine cluster. Each blossom has a glowing white star-shaped center and delicate radial vein lines. Add exactly 1 tiny pale blue butterfly near the upper-right text area. Typography: place large vertical Chinese title text on the right reading {argument name="main title" default="夏日安好"}, in elegant thin Song-style calligraphy, colored muted sky blue. To the lower right of the title, add smaller vertical text reading {argument name="subtitle" default="清风与花影"} in muted olive green, with a small red seal stamp beneath it and a very thin vertical divider line below. Visual style: airy, refined, vintage East Asian botanical illustration, soft granulation, faded pastel palette of blue, pink, lavender, sage, and teal, gentle ink texture, no hard outlines, no modern objects. Constraints: keep the design calm and uncluttered, preserve the broad blank ivory space on the right, avoid photorealism, avoid extra text, avoid borders or watermark.