Added few functions

lib/body-scroll-lock.ts

@@ -0,0 +1,45 @@
+'use client';
+
+/**
+ * Gère le verrouillage du scroll du body quand des modales sont ouvertes.
+ * Gère plusieurs modales empilées via un compteur.
+ */
+let lockCount = 0;
+let savedScrollY = 0;
+
+export function lockBodyScroll() {
+  lockCount++;
+  if (lockCount === 1) {
+    savedScrollY = window.scrollY;
+    document.documentElement.style.overflow = 'hidden';
+    document.body.style.overflow = 'hidden';
+    document.body.style.position = 'fixed';
+    document.body.style.top = `-${savedScrollY}px`;
+    document.body.style.left = '0';
+    document.body.style.right = '0';
+  }
+}
+
+export function unlockBodyScroll() {
+  if (lockCount > 0) lockCount--;
+  if (lockCount === 0) {
+    document.documentElement.style.overflow = '';
+    document.body.style.overflow = '';
+    document.body.style.position = '';
+    document.body.style.top = '';
+    document.body.style.left = '';
+    document.body.style.right = '';
+    window.scrollTo(0, savedScrollY);
+  }
+}
+
+import { useEffect } from 'react';
+
+export function useBodyScrollLock(isOpen: boolean) {
+  useEffect(() => {
+    if (isOpen) {
+      lockBodyScroll();
+      return () => unlockBodyScroll();
+    }
+  }, [isOpen]);
+}