# Bone Flow #125 Blend Specification v1.0

## Formal responsibility
描画時の合成方法を管理する。

## Formal modes
1. Normal
2. Multiply
3. Screen
4. Overlay
5. Darken
6. Lighten
7. Difference
8. Add

## Runtime mapping
The Runtime uses CSS `mix-blend-mode` for DOM drawing composition. `Add` maps to CSS `plus-lighter`; the formal Bone Flow name remains `Add`.

## HTML Functional Class
`bf-blend` is the single normal-use class. `data-blend-mode` selects the formal mode.

## Responsibility boundary
#125 does not own #124 Filter, #117 Animation, #118 Transition, #120 Trigger, #121 Timeline, or #123 Particle behavior.

## Status
Development / Candidate until USER LOCALHOST confirmation.