compact tightens the layout - an embedded checkout, or one in a WebView.
platform?
"auto" | Platform
Pin it to override detection.
style?
CSSProperties
Custom properties, for a brand that lives in a token pipeline rather than a stylesheet. appearanceToStyle() in @checkout-kit/ui builds one; plain CSS on .ck-root still works and is the shorter path when the brand is already written down in CSS.