加州城市复古旅行海报

创作一张精致的复古旅行海报，采用世纪中叶现代加州插画风格，呼应高端1950s–1960s丝网印刷旅游海报的视觉语言。

构图：竖版2:3海报，布局简洁居中，顶部以间距宽松的几何无衬线字体呈现醒目的优雅城市名称，下方用较小的大写字母写上“CALIFORNIA”，并以一条细横线分隔。文字下方绘制一个边缘柔和的大型圆形／拱形天空景框，呈现城市天际线和标志性地标。运用层叠的前景山丘、蜿蜒小径、风格化植被和建筑地标，营造强烈的纵深感。

视觉风格：扁平编辑插画、简化的几何形状、微妙的纸张纹理、略显风化的丝网印刷质感、克制的细节、柔和的边缘、精致的复古色块搭配、极少阴影；不采用照片写实风格，也不要过度依赖渐变的3D渲染。

配色：温暖的象牙白／奶油色背景、灰调粉蓝色天空、柔和的鼠尾草绿和橄榄绿、低饱和蓝绿色、温暖的米白色建筑、炭灰色／海军蓝文字，以及克制的陶土色点缀。整体低饱和、协调而怀旧。

字体：优雅纤细的几何无衬线字体、宽松的字间距、居中对齐，呈现高端旅行海报美感。文字应清晰且拼写正确。

洛杉矶：醒目呈现格里菲斯天文台、国会唱片大厦、棕榈树、好莱坞天际线、太平洋摩天轮／摩天轮、受主题大厦启发的建筑，以及延伸起伏的高架道路，将它们融入一幅协调统一的插画风景。

旧金山：醒目呈现金门大桥、泛美金字塔、科伊特塔、艺术宫、恶魔岛、连绵起伏的山丘、茂密的绿植和蜿蜒道路，将它们融入一幅协调统一的插画风景。

光线与氛围：明亮的加州日光、淡蓝色天空、几朵简洁的奶油色云朵，营造平静乐观的情绪和精致怀旧的旅游美感。

重要：保留经典复古旅行海报清晰的图形层级和宽敞的构图。避免照片般的写实效果、过多文字、现代汽车、人物、杂乱元素、标志、水印或过度饱和的色彩。

Create a sophisticated vintage travel poster in a mid-century modern California illustration style, matching the visual language of a premium 1950s–1960s screen-printed tourism poster.

Composition: vertical 2:3 poster, clean centered layout, large elegant city name at the top in widely spaced geometric sans-serif lettering, with “CALIFORNIA” beneath it in smaller uppercase letters and a thin horizontal divider. Below the typography, create a large soft-edged circular/arched sky vignette containing the city skyline and iconic landmarks. Use layered foreground hills, winding paths, stylized vegetation, and architectural landmarks to create strong depth.

Visual style: flat editorial illustration, simplified geometric forms, subtle paper grain, slightly weathered screen-print texture, restrained detail, soft edges, sophisticated vintage color blocking, minimal shadows, no photorealism, no gradients-heavy 3D rendering.

Color palette: warm ivory/cream background, dusty powder blue sky, muted sage and olive greens, desaturated teal, warm off-white architecture, charcoal/navy typography, and restrained terracotta accents. Low saturation, harmonious and nostalgic.

Typography: elegant thin geometric sans-serif, generous letter spacing, centered alignment, premium travel-poster aesthetic. Text should be crisp and correctly spelled.

For Los Angeles: prominently feature Griffith Observatory, the Capitol Records Building, palm trees, the Hollywood skyline, the Pacific Wheel/ferris wheel, the Theme Building-inspired architecture, and sweeping elevated roadways, arranged into one cohesive illustrated landscape.

For San Francisco: prominently feature the Golden Gate Bridge, Transamerica Pyramid, Coit Tower, Palace of Fine Arts, Alcatraz Island, rolling hills, dense greenery, and a winding road, arranged into one cohesive illustrated landscape.

Lighting & atmosphere: bright California daylight, pale blue sky, a few simple cream-colored clouds, calm optimistic mood, refined nostalgic tourism aesthetic.

Important: preserve the clean graphic hierarchy and spacious composition of classic vintage travel posters. Avoid photographic realism, excessive text, modern cars, people, clutter, logos, watermarks, or overly saturated colors.