Style presets (academic / web / tech)

One figure, multiple finishes: a paper-grade default, a screen-friendly web look, and a dark "tech" skin — all from the same declared geometry and content. Style lives in token dictionaries; the figure script never hardcodes a color.

When to use

• The same structural figure must ship in several looks (paper, slide deck, promo screen) and you do not want to re-draw it per style.
• Works with any route that declares style separately: parametric-diagram, declarative-engine, hand-written SVG with a shared style block.

The three presets

Usage

import sys
sys.path.insert(0, str(Path(__file__).resolve().parent.parent))  # folder containing style_presets.py
from style_presets import get_style, names

S = get_style("academic")   # default when called with no argument; returns a copy you may tweak
# every color / font / radius / effect in the figure script reads S["..."] — no hex literals

CLI: --style academic|web|tech|all (default academic; all emits every finish in one run). See examples/make_gpu_flow_fig.py, which regenerates the three GPU-pipeline figures in examples/fig-gpu-flow-*.svg from one declaration.

Token contract

get_style() asserts a fixed key set (see REQUIRED_KEYS in style_presets.py): canvas/header (page_bg, head, head_bg, head_rule, head_bar, date_style, …), text/line (ink, muted, faint, line, text_mid), cards (card, card_edge, card_r, fx = none|soft|glow, badge_bg/badge_fg), accent semantics (gpu_* — your figure's primary accent), neutral semantics (cpu_*), fittings (off_fill/off_dash, env_fill/env_fg, table_head, arrow, note_*), and typography/radius (font_title, font_body, font_mono, chip_r). Adding a preset = adding one dict; the figure script never changes.

Fonts use fallback lists for Latin/CJK splitting: academic pairs Times New Roman, SimHei (titles) with Times New Roman, SimSun (small notes).

Discipline

1. Style and geometry/content are separate declarations. Changing a skin must not touch coordinates or text; hex literals are banned from the figure script.
2. ≤3 accents + neutrals still holds inside every preset — orange only marks the accent semantics in academic, cyan only in tech.
3. Effects are tiered: academic = fx: none; web = soft (low-opacity dark shadow); tech = glow (accent-colored, accent elements only).
4. Dark skins: verify contrast on the render, not the hex math. 1.2 px hairlines lose ~60 % of theoretical contrast to antialiasing — pick line/note_line/text tokens so the exported PNG shows ≥40 gray levels against the real background (see visual-acceptance, dark-theme contrast check).