feat(tender-details): improve scrolling behavior and header offset management

- Introduced a new constant for the tender section scroll offset to enhance scrolling behavior when navigating to sections.
- Updated the scroll-to-section logic to account for the sticky header and added a small gap for better visual alignment.
- Refactored the useTenderSectionScrollSpy hook to utilize the new scroll offset, ensuring consistent behavior across sections.
- Improved code organization by separating scroll offset calculations into a dedicated function.

src/app/tenders/[details]/constants.ts

@@ -13,7 +13,11 @@ export const TENDER_SECTION_IDS = {
   aiSummary: "tender-section-ai-summary",
 } as const;
 
-export const HEADER_SCROLL_MARGIN = "scroll-mt-[5.5rem]";
+/** Sticky app header clearance — keep in sync with `getTenderSectionScrollOffset`. */
+export const TENDER_SECTION_SCROLL_OFFSET_PX = 96;
+
+/** For hash / native scroll-into-view (matches offset above). */
+export const HEADER_SCROLL_MARGIN = "scroll-mt-24";
 
 /** Body area only: center content in the card; ShowcaseSection `title` is unchanged */
 export const SHOWCASE_CENTERED_BODY = {

src/app/tenders/[details]/hooks/use-tender-section-scroll-spy.ts

@@ -1,4 +1,5 @@
 import { useEffect, useState } from "react";
+import { getTenderSectionScrollOffset } from "../scroll-to-section";
 
 export function useTenderSectionScrollSpy(sectionIds: string[]) {
   const [activeId, setActiveId] = useState(sectionIds[0] ?? "");
@@ -17,7 +18,7 @@ export function useTenderSectionScrollSpy(sectionIds: string[]) {
     if (sectionIds.length === 0) return;
 
     const pickActive = () => {
-      const offset = 96;
+      const offset = getTenderSectionScrollOffset();
       const scrollY = window.scrollY;
       const viewportHeight = window.innerHeight;
       const documentHeight = Math.max(

src/app/tenders/[details]/scroll-to-section.ts

@@ -1,11 +1,34 @@
+import { TENDER_SECTION_SCROLL_OFFSET_PX } from "./constants";
+
+const SECTION_SCROLL_GAP_PX = 8;
+
+/** Pixels to leave above the section top (sticky header + small gap). */
+export function getTenderSectionScrollOffset(): number {
+  if (typeof document === "undefined") {
+    return TENDER_SECTION_SCROLL_OFFSET_PX + SECTION_SCROLL_GAP_PX;
+  }
+  const header = document.querySelector("header");
+  const headerHeight = header?.getBoundingClientRect().height ?? 0;
+  return (
+    Math.max(TENDER_SECTION_SCROLL_OFFSET_PX, headerHeight) +
+    SECTION_SCROLL_GAP_PX
+  );
+}
+
 export function scrollToTenderSection(id: string) {
   const el = document.getElementById(id);
   if (!el) return;
+
   const reduceMotion =
     typeof window !== "undefined" &&
     window.matchMedia("(prefers-reduced-motion: reduce)").matches;
-  el.scrollIntoView({
+
+  const offset = getTenderSectionScrollOffset();
+  const top =
+    el.getBoundingClientRect().top + window.scrollY - offset;
+
+  window.scrollTo({
+    top: Math.max(0, top),
     behavior: reduceMotion ? "auto" : "smooth",
-    block: "start",
   });
 }