修正后的通用前缀（重点加视角约束）： warm healing watercolor style, casual...

修正后的通用前缀（重点加视角约束）： warm healing watercolor style, casual merge mobile game board element, top-down view directly from above, flat lay, 90 degree overhead, perfectly flat, no thickness, no side visible, no 3d extrusion, no isometric, single element only, on ly one item in the entire image, centered, transparent background, soft hand-painted watercolor texture, warm gentle t ones, clean minimal design, no text, no watermark, no border ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── cell_bg 棋盘格子背景（建议尺寸 96×96）： a single flat rounded square board cell tile, soft warm cream or light beige solid fill, gentle watercolor paper textu re, plain empty surface, perfectly flat from above, no objects on it, no symbols, no frame, just a clean flat cell bac kground, 96x96 cell_highlight 格子高亮（建议尺寸 96×96）： a single flat rounded square selection highlight frame, soft warm yellow or pale green flat glowing border ring, compl etely empty center, only the outer flat glow outline, perfectly flat from above, no fill inside, no objects inside, no symbols, 96x96 cell_blocked 被封锁格子（建议尺寸 96×96）： a single flat rounded square disabled board tile, soft muted warm gray solid fill, subtle faint flat cross mark in cen ter, perfectly flat from above, blocked inactive status, no other symbols, no objects on it, 96x96 item_shadow 拖拽阴影（建议尺寸 128×128）： a single flat round drop shadow, soft dark gray or warm brown radial gradient, perfectly flat from above, feathered so ft edges, completely empty center where item sits, no object in middle, just the flat diffused shadow circle, 128x128 merge_particle 合成粒子（建议尺寸 32×32）： a single tiny flat sparkle burst, small warm golden flat star shape, flat glowing center with soft fade outward, perfe ctly flat from above, magical merge game effect, no solid 3d shapes, 32x32 ────────────────────────────────────────────────────────────────────────────────────────────────────────────────────── 负面词（必须加上视角相关）： isometric, 3d, dimensional, side view, thickness, extruded, perspective, tilted, angled, slanted, multiple elements, m ultiple items, grid layout, icon, clock, key, lock, gear, text, logo, watermark, border, photo, realistic shadow