/**
* Returns a CSS color only when the browser parses it as the `color` property.
*
* This is also the swatch guard. A caller-supplied swatch color has to be rejected unless it is
* recognizable CSS color syntax -- both to stop it breaking out of the single declaration it is
* assigned to (`;`, `{`, `}` terminate/reopen a declaration) and to stop non-color values such as
* `url(...)` from being accepted, which `background` also parses and would fetch as soon as the
* swatch renders. That matters even when the value is applied through Lit's `styleMap` directive
* rather than raw string interpolation: `styleMap`'s FIRST commit for a given attribute part
* serializes the whole `style` value as one string (only later updates take the safe
* `CSSStyleDeclaration.setProperty()` path), so an unsanitized value could still inject on that
* first render.
*/
export declare function sanitizeCssColor(color:unknown):string|undefined;
/** Returns a CSS length only when it is valid for the named sizing property. */
export declare function sanitizeCssLength(value:unknown,property?:'height'|'max-height'):string|undefined;
/** Returns a one-to-four-value inset shorthand only when the browser accepts it. */
export declare function sanitizeCssInset(value:unknown):string|undefined;export type SafeCssResize='none'|'both'|'horizontal'|'vertical';
/** Narrows an untrusted runtime value to the native CSS `resize` vocabulary. */
export declare function sanitizeCssResize(value:unknown,fallback:SafeCssResize):SafeCssResize;export interface SafePercentRect{x:number;y:number;width:number;height:number;}
/** Validates public percentage geometry before it reaches an inline style. */
export declare function sanitizePercentRect(value:unknown):SafePercentRect|undefined;