City Public Library Open Day Main Poster AI Image Prompt

Create a minimalist ceremonial information poster around any given theme. The first impression must be a large area of warm white empty space where the main title is precisely centered, engaging in solemn alignment with three thematic symbols: transform the core name, participants, or keywords provided by the theme into a large thin-stroke title at the top, a set of recognizable abstract logos in the center, and solid color blocks on both sides; semantics may change but order remains constant. Retain high-ratio whitespace, vertical central axis, upper-lower zoning, and the pause feeling of thin black horizontal lines; arrange all elements restrainedly like an exhibition catalog or international institutional yearbook. Use high-contrast fine serifs or equivalent glyph structures for the main text, with open counters, slender strokes, sharp terminals, and spacious rhythm, maintaining a slender skeleton, loose tracking, clear recognition, and calm breathing when switched to any writing system, rather than copying a specific Latin font. Extract two high-purity representative colors from the theme for hard-edged squares; use only black lines and minimal solid geometry for the central logo; keep the background as slightly paper-textured warm white, avoiding gradients, shadows, and decorative textures. Place subtitles and small explanatory text at a lower center of gravity at the bottom, with footer micro-information pressing the edges, creating a contrast where grand themes are tamed by museum-style whitespace; failure symptoms include crowded elements, chaotic colors, thick fonts, realistic icons, or the poster losing its cold ritual order. Set the theme to "City Public Library Open Day" for a public cultural institution event main poster: use indigo blue and cinnabar red as the two high-purity square colors; abstract opened book pages and door arches with black lines in the center, letting the symbol group fall steadily below the title along the vertical axis; place the main title in the center of the upper half, with subtitles and dates forming a sparse two-level information hierarchy below, retaining large areas of warm white whitespace and thin black line pauses; aspect ratio is vertical 3:4.