Root cause: WeChat miniprogram components have style isolation by default.
Changing tab bar hardcoded #888/#666 to var(--text-secondary) broke
because --text-secondary was only defined on page{} in app.wxss and
couldn't cascade into the custom-tab-bar component.
Fix:
1. theme.js: inject BASE_VARS (--text, --text-secondary, --border, etc.)
into themeStyle string so they're available via inline style everywhere
2. Add styleIsolation: apply-shared to all 3 component JSONs so page-level
CSS variables cascade into components
- var→const/let, function→arrow/class across all 13 JS files
- Timer: prototype→class with ES6 getters
- plan days: IIFE→Array.from declarative generation
- storage/plan: unified formatDate via util.js
- Bugfix: getPlanDay now filters by planId (plan switch accuracy)
- Bugfix: getTodayRecord searches all months (cross-month boundary)
- WXML/WXSS unchanged; public API unchanged
lc