import { ReflectionTarget } from './constants';
export declare function readCornerRadius(el: HTMLElement): number;
/**
 * Read the visible "hairline" geometry of the host so the 1-px stroke
 * reflection sits exactly on the host's existing ring.
 *
 * Returns the visible thickness (`width`) and the OUTWARD extent past the
 * padding-box edge (`outerCssPx`) — the wrap is overscanned by `outerCssPx`
 * on every side so its outer rim lines up with the host's visible silhouette.
 *
 * Source contributions:
 *   - CSS `border-*-width` (max across the 4 sides)
 *   - smallest `inset` `box-shadow` with spread > 0
 *   - smallest outset `box-shadow` with spread > 0
 */
export declare function readHairlineSpec(el: HTMLElement): {
    width: number;
    outerCssPx: number;
};
export declare function attachObservers(t: ReflectionTarget): void;
export declare function detachObservers(t: ReflectionTarget): void;