diff --git a/script.js b/script.js
index 64785ae..4efa218 100644
--- a/script.js
+++ b/script.js
@@ -1,4 +1,5 @@
 const STORAGE_KEY = "ecosystem-panel-preferences";
+const COLLAPSE_STORAGE_KEY = "ecosystem-panel-collapse-state";
 
 // Меняй навигацию здесь: разделы -> подразделы -> элементы.
 // url можно заменить на реальные адреса, tags помогают поиску.
@@ -141,6 +142,7 @@ const defaultPreferences = {
 const availableViews = ["cards", "list", "compact-cards", "compact-list"];
 
 const preferences = { ...defaultPreferences, ...readPreferences() };
+const collapseState = readCollapseState();
 const catalog = document.querySelector("[data-catalog-root]");
 const navTree = document.querySelector("[data-nav-tree]");
 const searchInput = document.querySelector("[data-search-input]");
@@ -172,6 +174,9 @@ navTree.addEventListener("click", (event) => {
   focusCatalogTarget(button.dataset.focusTarget);
 });
 
+navTree.addEventListener("toggle", handleDetailsToggle, true);
+catalog.addEventListener("toggle", handleDetailsToggle, true);
+
 settingsToggle.addEventListener("click", () => {
   const isOpen = settingsPanel.classList.toggle("is-open");
   settingsOverlay.classList.toggle("is-open", isOpen);
@@ -235,11 +240,12 @@ function createItem(number, title, type, tags = [], url = "#") {
 
 function renderCatalog() {
   const query = normalize(searchInput.value);
+  const forceOpen = Boolean(query);
   const fragment = document.createDocumentFragment();
   let visibleItems = 0;
 
   ecosystemSections.forEach((section) => {
-    const sectionElement = createSectionElement(section);
+    const sectionElement = createSectionElement(section, forceOpen);
     let visibleGroups = 0;
     let sectionVisibleItems = 0;
 
@@ -252,7 +258,7 @@ function renderCatalog() {
 
       visibleGroups += 1;
       sectionVisibleItems += filteredItems.length;
-      sectionElement.querySelector(".section-groups").append(createGroupElement(group, filteredItems));
+      sectionElement.querySelector(".section-groups").append(createGroupElement(group, filteredItems, forceOpen));
     });
 
     if (visibleGroups) {
@@ -273,12 +279,13 @@ function renderCatalog() {
 
 }
 
-function createSectionElement(section) {
+function createSectionElement(section, forceOpen = false) {
   const sectionElement = document.createElement("details");
   sectionElement.className = "catalog-section";
   sectionElement.id = getSectionId(section);
+  sectionElement.dataset.collapseKey = sectionElement.id;
   sectionElement.tabIndex = -1;
-  sectionElement.open = true;
+  sectionElement.open = forceOpen || getSavedOpenState(sectionElement.dataset.collapseKey);
   sectionElement.innerHTML = `
     <summary class="section-head">
       <div>
@@ -296,12 +303,13 @@ function createSectionElement(section) {
   return sectionElement;
 }
 
-function createGroupElement(group, items) {
+function createGroupElement(group, items, forceOpen = false) {
   const groupElement = document.createElement("details");
   groupElement.className = "catalog-group";
   groupElement.id = getGroupId(group);
+  groupElement.dataset.collapseKey = groupElement.id;
   groupElement.tabIndex = -1;
-  groupElement.open = true;
+  groupElement.open = forceOpen || getSavedOpenState(groupElement.dataset.collapseKey);
 
   const cards = items.map(createCardElement);
   groupElement.innerHTML = `
@@ -384,7 +392,8 @@ function renderNavigationTree() {
   ecosystemSections.forEach((section) => {
     const sectionNode = document.createElement("details");
     sectionNode.className = "tree-section";
-    sectionNode.open = true;
+    sectionNode.dataset.collapseKey = getTreeSectionId(section);
+    sectionNode.open = getSavedOpenState(sectionNode.dataset.collapseKey);
 
     const sectionSummary = document.createElement("summary");
     sectionSummary.innerHTML = `
@@ -398,7 +407,8 @@ function renderNavigationTree() {
     section.groups.forEach((group) => {
       const groupNode = document.createElement("details");
       groupNode.className = "tree-group";
-      groupNode.open = true;
+      groupNode.dataset.collapseKey = getTreeGroupId(group);
+      groupNode.open = getSavedOpenState(groupNode.dataset.collapseKey);
 
       const groupSummary = document.createElement("summary");
       groupSummary.innerHTML = `
@@ -446,12 +456,34 @@ function focusCatalogTarget(targetId) {
 
   target.closest(".catalog-section")?.setAttribute("open", "");
   target.closest(".catalog-group")?.setAttribute("open", "");
+  persistOpenedAncestor(target.closest(".catalog-section"));
+  persistOpenedAncestor(target.closest(".catalog-group"));
   target.scrollIntoView({ behavior: "smooth", block: "center" });
   target.focus({ preventScroll: true });
   target.classList.add("is-focused");
   window.setTimeout(() => target.classList.remove("is-focused"), 1200);
 }
 
+function handleDetailsToggle(event) {
+  const details = event.target;
+
+  if (!(details instanceof HTMLDetailsElement) || !details.dataset.collapseKey) {
+    return;
+  }
+
+  collapseState[details.dataset.collapseKey] = details.open;
+  saveCollapseState();
+}
+
+function persistOpenedAncestor(details) {
+  if (!details?.dataset.collapseKey) {
+    return;
+  }
+
+  collapseState[details.dataset.collapseKey] = true;
+  saveCollapseState();
+}
+
 function attachCardInteractions() {
   document.querySelectorAll(".nav-card").forEach((card) => {
     let leaveTimer;
@@ -525,6 +557,14 @@ function getGroupId(group) {
   return `group-${group.id}`;
 }
 
+function getTreeSectionId(section) {
+  return `tree-${getSectionId(section)}`;
+}
+
+function getTreeGroupId(group) {
+  return `tree-${getGroupId(group)}`;
+}
+
 function getItemId(item) {
   return `item-${item.number.replaceAll(".", "-")}`;
 }
@@ -545,6 +585,22 @@ function savePreferences(nextPreferences) {
   localStorage.setItem(STORAGE_KEY, JSON.stringify(nextPreferences));
 }
 
+function getSavedOpenState(key) {
+  return collapseState[key] ?? true;
+}
+
+function readCollapseState() {
+  try {
+    return JSON.parse(localStorage.getItem(COLLAPSE_STORAGE_KEY)) || {};
+  } catch {
+    return {};
+  }
+}
+
+function saveCollapseState() {
+  localStorage.setItem(COLLAPSE_STORAGE_KEY, JSON.stringify(collapseState));
+}
+
 function closeSettingsPanel() {
   settingsPanel.classList.remove("is-open");
   settingsOverlay.classList.remove("is-open");