# Merge upstream master (CSS perf #779) into mod/master-img

**Date**: 2026-02-15

## Task

Merge the latest changes from `master` (upstream) into `mod/master-img`.

## Changes Merged

One upstream commit: `46c2109 perf: Improve large CSS files handling (#779)`

This commit significantly refactored the CSS subsystem:
- Streaming CSS parser with `StackBuffer` for zero-heap parsing
- Extracted `parseDeclarationIntoStyle()` from inline logic
- Rule limits and selector validation
- `CssParser` now owns its `cachePath` and manages caching internally
- CSS loading skipped when "Book's Embedded Style" is off

## Conflicts Resolved

### Section.cpp (2 regions)
- Combined mod's image support variables (`contentBase`, `imageBasePath`) with master's new CSS parser loading pattern (`cssParser->loadFromCache()`)
- Merged constructor call: kept mod's `epub`, `contentBase`, `imageBasePath` params while adopting master's `cssParser` local variable pattern
- Added master's `cssParser->clear()` calls on error/success paths

### CssParser.cpp (1 region)
- Accepted master's complete rewrite of the CSS parser
- Ported mod's `width` CSS property handler into the new `parseDeclarationIntoStyle()` function

## Auto-merged Files Verified
- `CssStyle.h`: `width` property and supporting code preserved
- `platformio.ini`: `PNGdec` library and `PNG_MAX_BUFFERED_PIXELS` preserved; `[env:mod]` section intact; master's `gnu++2a` and `build_unflags` applied
- `ChapterHtmlSlimParser.h`: image/table support members preserved
- `RecentBooksStore.cpp`: `removeBook()` method preserved
- `Epub.cpp`, `Epub.h`, `CssParser.h`, `ReaderActivity.cpp`: auto-merged cleanly

## Build Result
- `pio run -e mod` succeeded with zero errors

## Commit
- `744d616 Merge branch 'master' into mod/master-img`