[argszero]

Summary

Rant 2026-08-17T18:06:09 (UI/UE 第三轮多角度深化), item B — 亮色主题: the UI is currently dark-only; add a light theme via CSS-variable refactor, with a sidebar toggle (sun/moon SVG), localStorage persistence, and prefers-color-scheme respected on first load.

Changes

• CSS: :root[data-theme="light"] redefines the full color set (--bg/--bg-soft/--bg-card/--bg-hover/--border/--text/--text-dim/--text-mute/--accent/--accent-soft/--accent-text/--ok/--warn/--danger + shadows). Previously hard-coded colors extracted to semantic vars shared by both themes: --table-row-border, --table-stripe, --card-hover-border, --card-shadow, --danger-soft, --danger-text, --spin-track, --overlay;
• HTML: #theme-toggle button in the sidebar top (sun icon; moon icon shown in light theme via CSS);
• JS: init reads localStorage["atp-theme"], falling back to prefers-color-scheme; click toggles document.documentElement.dataset.theme + saves + toast feedback;
• Both themes keep clear contrast for body / secondary text / borders;
• Docs: docs/user-stories.md v1.18 changelog adds item B; ui/README.md 主题约定 section.

Acceptance

Light theme toggleable with localStorage memory; first load respects system preference.

Tests

• node --check on app.js — syntax OK
• Theme logic tests 4/4 PASS (default dark w/o saved+system dark; toggle → light + saved; toggle back → dark + saved)
• DOM-stub init + shortcuts + field-error smokes — no ReferenceError
• cargo test — 1 passed
• cargo fmt --check — clean