Mainframe Engine logo ("C3 Circuit")

File	Use
logo.svg	Master artwork, full detail — use at 64 px and above
logo-small.svg	Simplified artwork — use at 48 px and below (title bars, favicons, small icons)
logo-macos.svg	logo.svg on Apple’s app-icon grid: 1024 canvas, 824 px tile centred (100 px transparent margin), corner radius ≈ 185 px — for logo.icns and the macOS Dock icon
png/logo-macos-{16…1024}.png	Rendered from logo-macos.svg (the .icns iconset)
png/logo-{16,24,32,48}.png	Rendered from logo-small.svg
png/logo-{64,128,256,512,1024}.png	Rendered from logo.svg
logo.ico	Windows icon (16–256, 7 sizes) — the editor’s ApplicationIcon
logo.icns	macOS icon, from logo-macos.svg — the editor app bundle’s CFBundleIconFile

Engine content carries copies for apps (ContentPaths: Content/Brand/logo-{32,48,256,512}.png, logo-macos-512.png): window icons (EngineOptions.IconPath — logo-macos-512.png on macOS, where it is the Dock icon; logo-48.png elsewhere) and the editor splash screen (RmlUi renders PNG, not SVG). Windows .ico and Linux PNGs stay full-bleed, as is their convention.

Colours

Part	Colour
Tile	#172554
Grid dots	#1E40AF
“M” and edge nodes	#38BDF8
Core	#F59E0B

Regenerating

just brand re-renders every PNG, the .ico and (on macOS) the .icns from the SVGs and refreshes the engine content copies. It needs Inkscape; a single size by hand:

inkscape logo.svg -w 256 -h 256 -o png/logo-256.png          # >= 64 px
inkscape logo-small.svg -w 32 -h 32 -o png/logo-32.png       # <= 48 px

The .ico is packed by build/brand/make-ico.py (no dependencies); the .icns by iconutil -c icns from an iconset. Do not redesign the artwork in place — the SVGs are the source of truth.