/**
 * Sizing for the navigation spine's tick rail.
 *
 * The spine is fixed to the viewport's vertical center, so on a document with
 * hundreds of operations a tick per item would run off both ends of the screen.
 * These two functions cap it instead: `spineTickBudget` works out how many item
 * ticks fit, and `allocateSpineTicks` shares that budget out across sections.
 *
 * The px values below mirror the spine's Tailwind classes in Navigation.tsx and
 * have to move with them.
 */
/**
 * How many item ticks fit in the spine's share of the viewport, once each
 * section's own parent tick and the gaps between sections are paid for.
 * A zero `viewportHeight` means server-side rendering, where there's no
 * viewport to cap against.
 */
export declare function spineTickBudget(viewportHeight: number, sectionCount: number): number;
/**
 * Hands out `budget` item ticks across sections holding `counts` items each.
 *
 * Under budget, every item keeps its own tick. Over it, each section is
 * guaranteed one tick and the rest is shared out in proportion to size, so a
 * section stays visibly bigger than its neighbours even once its ticks stand
 * for several items apiece. Rounding down can leave a few ticks of the budget
 * unspent, which only makes the spine slightly shorter than its cap.
 */
export declare function allocateSpineTicks(counts: number[], budget: number): number[];