请生成一张竖版高质感女性情绪写真，主题为「逆光美背·女性情绪写真」。
核心要求：
画面的绝对重点是“美背”，通过露背结构、肩颈线条、肩胛骨、脊柱中线、腰背曲线和逆光轮廓来呈现女性美。不是普通女性写真，也不是普通穿搭图，背部必须是主视觉核心，脸只作为辅助。
人物设定：
成年女性，真实自然，气质可为温柔、清冷、慵懒、文艺、轻熟或安静。人物不要网红脸，不要塑料感，不要夸张妆容。可侧脸、回眸、低头或闭眼，但正脸不是重点。
姿态要求：
姿态必须服务于背部展示，例如背对镜头微微回头、侧身站立、侧坐、抬手整理头发、低头蜷身、斜倚窗边、半躺回眸、披衣下滑等。动作自然，不要僵硬摆拍，不要正面直视镜头。
露背结构：
必须有明确的露背设计，可为低背长裙、吊带裙、露背礼服、针织外套滑落、薄纱披肩、浴袍半披、宽松衬衫滑肩、丝质罩衫半落等。重点表现肩线、肩胛骨、背中线、腰背收束和布料与肌肤之间的高级过渡。
服装与材质：
服装选择轻柔、垂坠、带有透光感和褶皱感的材质，如薄纱、真丝、针织、棉麻、细闪纱、浴袍质地、软垂感长裙。布料要参与构图，形成半遮半露、滑落、包裹、垂挂的层次，但不能厚重。
场景：
场景为卧室、窗边、床上、白墙房间、民宿、酒店房间、木质空间或复古公寓。背景简洁克制，少量床品、窗帘、木椅、花束、地板等元素即可，不能喧宾夺主。
光线要求：
采用自然光或柔和暖光，以逆光、侧逆光、窗边光为主。重点是让光打到背部，勾出肩颈边缘、肩胛骨轮廓、腰线和发丝高光。可使用晨光、黄昏金光、柔雾散射光或冷白窗光，但背部受光状态必须成立。
构图：
竖版构图，画幅可为 9:16、3:4 或 4:5。人物是绝对主角，视觉重心放在背部、肩颈和腰背曲线上。可采用半身、七分身、近景或全身，但不要让场景抢走主体。
氛围：
整体氛围安静、柔软、私密、克制、高级，像真实摄影师拍摄的电影感情绪写真。重点不是直白性感，而是通过“美背 + 逆光 + 柔软布料 + 自然姿态”表达女性美。
画质要求：
真实摄影感、电影感、柔雾胶片感、细腻肤色、真实皮肤质感、浅景深、轻微颗粒感、画面通透自然。不要 AI 塑料感，不要 CG 感，不要错误手指，不要肢体畸形，不要低俗色情化表达，不要文字、水印、Logo、边框。
最终效果：
一张以“美背”为主视觉核心的高完成度女性情绪写真，通过露背结构、肩颈背部线条、柔光逆光和柔软布料来呈现克制而高级的女性美。
Please generate a vertical high-quality female emotional portrait with the theme "Backlit Beautiful Back · Female Emotional Portrait".
Core Requirements:
The absolute focus of the image is the "beautiful back", presenting female beauty through backless structures, shoulder and neck lines, shoulder blades, the central spine line, lumbar-back curves, and backlit silhouettes. It is not a common female portrait or a general outfit photo; the back must be the core visual focus, with the face serving only as an auxiliary.
Character Setting:
Adult female, real and natural, temperament can be gentle, cool, lazy, literary, mature, or quiet. No internet celebrity face, no plastic feel, no exaggerated makeup. Can be side profile, looking back, head down, or eyes closed, but the front face is not the focus.
Posture Requirements:
Postures must serve the display of the back, such as turning the head slightly with the back to the camera, standing sideways, sitting sideways, raising a hand to tidy hair, curling up with the head down, leaning against a window, half-lying and looking back, clothes sliding down, etc. Actions should be natural, no stiff poses, no looking directly at the camera.
Backless Structure:
Must have a clear backless design, which can be a low-back long dress, a slip dress, a backless evening gown, a knitted cardigan sliding off, a tulle shawl, a half-draped bathrobe, a loose shirt sliding off the shoulder, a half-fallen silk blouse, etc. Focus on expressing the shoulder lines, shoulder blades, back midline, lumbar-back narrowing, and the high-end transition between fabric and skin.
Clothing and Materials:
Choose soft, draped materials with translucency and pleats, such as tulle, silk, knitwear, cotton and linen, fine shimmering yarn, bathrobe texture, soft draped long dresses. Fabric should participate in the composition, forming layers of semi-coverage, sliding, wrapping, and hanging, but must not be heavy.
Scene:
The scene is a bedroom, by a window, on a bed, a white-walled room, a B&B, a hotel room, a wooden space, or a vintage apartment. The background is simple and restrained, with a small amount of elements like bedding, curtains, wooden chairs, bouquets, floors, etc., which should not overshadow the main subject.
Lighting Requirements:
Use natural light or soft warm light, mainly backlighting, side backlighting, and window light. The focus is to let the light hit the back, outlining the edges of the neck and shoulders, the contour of the shoulder blades, the waistline, and hair highlights. Morning light, golden sunset light, soft mist diffused light, or cool white window light can be used, but the light status on the back must be established.
Composition:
Vertical composition, aspect ratio can be 9:16, 3:4, or 4:5. The person is the absolute protagonist, with the visual focus placed on the back, neck, and lumbar-back curves. Half-body, three-quarter body, close-up, or full body can be used, but do not let the scene steal the subject.
Atmosphere:
The overall atmosphere is quiet, soft, private, restrained, and high-end, like an emotional portrait with a cinematic feel shot by a real photographer. The point is not blatant sexiness, but expressing female beauty through "beautiful back + backlighting + soft fabrics + natural posture".
Quality Requirements:
Real photographic feel, cinematic feel, soft mist film feel, delicate skin tone, real skin texture, shallow depth of field, slight graininess, transparent and natural image. No AI plastic feel, no CG feel, no wrong fingers, no limb deformities, no vulgar or pornographic expressions, no text, watermarks, logos, or borders.
Final Effect:
A high-completion female emotional portrait with the "beautiful back" as the core visual focus, presenting restrained and high-end female beauty through backless structures, shoulder-neck-back lines, soft backlighting, and soft fabrics.
