diff --git a/frontend/js/labs/_loader.js b/frontend/js/labs/_loader.js
new file mode 100644
index 0000000..f8435a1
--- /dev/null
+++ b/frontend/js/labs/_loader.js
@@ -0,0 +1,76 @@
+'use strict';
+/*
+ * LabLoader — ленивый загрузчик кода симуляций (контент-движок, Фаза 3).
+ *
+ * Тяжёлый код симуляций (~2.5 МБ) и three.js (~600 КБ) больше НЕ грузятся на старте.
+ * При открытии симуляции LabLoader.ensure(id) подгружает её файлы (по манифесту
+ * window.SIM_DEPS из _sim_deps.js) и, при необходимости, three.js — затем резолвит.
+ *
+ * Гарантия корректности (самовосстановление): если после загрузки указанных файлов
+ * глобальная open-функция (SIM_DEPS[id].open, напр. "_openPendulum") всё ещё не
+ * определена, грузятся ВСЕ ленивые файлы (window.LAB_LAZY_FILES). Поэтому ошибка в
+ * манифесте не может «сломать» симуляцию — в худшем случае грузится больше файлов
+ * (поведение как до Фазы 3). Манифест лишь оптимизирует объём загрузки.
+ *
+ * Все загрузки кешируются (по URL) и дедуплицируются.
+ */
+(function () {
+  var BASE = '/js/labs/';
+  var THREE_URL = 'https://cdn.jsdelivr.net/npm/three@0.149.0/build/three.min.js';
+  var _cache = {};       // url -> Promise
+  var _allLoaded = false;
+
+  function loadScript(url) {
+    if (_cache[url]) return _cache[url];
+    _cache[url] = new Promise(function (resolve, reject) {
+      var s = document.createElement('script');
+      s.src = url;
+      s.async = false;   // сохранить порядок при добавлении нескольких сразу
+      s.onload = function () { resolve(url); };
+      s.onerror = function () { delete _cache[url]; reject(new Error('LabLoader: не удалось загрузить ' + url)); };
+      document.head.appendChild(s);
+    });
+    return _cache[url];
+  }
+
+  function ensureThree() {
+    if (typeof window.THREE !== 'undefined') return Promise.resolve();
+    return loadScript(THREE_URL);
+  }
+
+  function loadFiles(files) {
+    return Promise.all((files || []).map(function (f) { return loadScript(BASE + f); }));
+  }
+
+  function loadAllLazy() {
+    if (_allLoaded) return Promise.resolve();
+    var list = window.LAB_LAZY_FILES || [];
+    return loadFiles(list).then(function () { _allLoaded = true; });
+  }
+
+  // ensure(id): загрузить всё необходимое для симуляции id, вернуть Promise.
+  function ensure(id) {
+    var dep = (window.SIM_DEPS && window.SIM_DEPS[id]) || null;
+    if (!dep) {
+      // нет манифеста для id — безопасно грузим всё
+      return loadAllLazy();
+    }
+    var p = dep.three ? ensureThree() : Promise.resolve();
+    return p
+      .then(function () { return loadFiles(dep.files); })
+      .then(function () {
+        var openName = dep.open;
+        if (openName && typeof window[openName] !== 'function') {
+          if (window.console) console.warn('[LabLoader] самовосстановление для "' + id + '": ' + openName + ' не найдена после загрузки ' + JSON.stringify(dep.files) + ' — гружу все ленивые файлы');
+          return loadAllLazy();
+        }
+      });
+  }
+
+  window.LabLoader = {
+    ensure: ensure,
+    ensureThree: ensureThree,
+    loadScript: loadScript,
+    loadAllLazy: loadAllLazy
+  };
+})();
diff --git a/frontend/js/labs/_sim_deps.js b/frontend/js/labs/_sim_deps.js
new file mode 100644
index 0000000..114a8b9
--- /dev/null
+++ b/frontend/js/labs/_sim_deps.js
@@ -0,0 +1,300 @@
+'use strict';
+/* Контент-движок, Фаза 3 — манифест зависимостей симуляций (СГЕНЕРИРОВАН).
+   id -> { open: имя глобальной _openX, files: [ленивые файлы], three: нужен ли three.js }.
+   Файлы загружаются лениво по клику (см. _loader.js). three.js — только для 3D-симуляций.
+   Самовосстановление в _loader: если после загрузки open-функция не определена,
+   грузятся ВСЕ ленивые файлы -> корректность не зависит от точности манифеста.
+   Регенерация: node tools/gen-sim-deps.js (см. CONTEXT). НЕ редактировать вручную. */
+window.SIM_DEPS = {
+  "graph": {
+    "open": "_openGraph",
+    "files": [],
+    "three": false
+  },
+  "projectile": {
+    "open": "_openProjectile",
+    "files": [
+      "projectile.js"
+    ],
+    "three": false
+  },
+  "collision": {
+    "open": "_openCollision",
+    "files": [
+      "collision.js"
+    ],
+    "three": false
+  },
+  "triangle": {
+    "open": "_openTriangle",
+    "files": [
+      "triangle.js"
+    ],
+    "three": false
+  },
+  "trigcircle": {
+    "open": "_openTrigCircle",
+    "files": [
+      "trigcircle.js"
+    ],
+    "three": false
+  },
+  "emfield": {
+    "open": "_openEMField",
+    "files": [
+      "emfield.js",
+      "logic.js"
+    ],
+    "three": false
+  },
+  "molphys": {
+    "open": "_openMolPhys",
+    "files": [
+      "brownian.js",
+      "diffusion.js",
+      "gas.js",
+      "states.js"
+    ],
+    "three": false
+  },
+  "circuit": {
+    "open": "_openCircuit",
+    "files": [
+      "circuit.js"
+    ],
+    "three": false
+  },
+  "chemistry": {
+    "open": "_openChemistry",
+    "files": [
+      "circuit.js",
+      "flask.js",
+      "ionexchange.js",
+      "reactions.js",
+      "redox.js"
+    ],
+    "three": false
+  },
+  "dynamics": {
+    "open": "_openDynamics",
+    "files": [
+      "forcesandbox.js",
+      "newton.js"
+    ],
+    "three": false
+  },
+  "crystal": {
+    "open": "_openCrystal",
+    "files": [
+      "crystal.js"
+    ],
+    "three": true
+  },
+  "orbitals": {
+    "open": "_openOrbitals",
+    "files": [
+      "orbitals.js"
+    ],
+    "three": true
+  },
+  "stereo": {
+    "open": "_openStereo",
+    "files": [
+      "stereo.js"
+    ],
+    "three": true
+  },
+  "chemsandbox": {
+    "open": "_openChemSandbox",
+    "files": [
+      "chemsandbox.js",
+      "collision.js"
+    ],
+    "three": false
+  },
+  "celldivision": {
+    "open": "_openCellDivision",
+    "files": [
+      "celldivision.js"
+    ],
+    "three": false
+  },
+  "photosynthesis": {
+    "open": "_openPhotosynthesis",
+    "files": [
+      "photosynthesis.js"
+    ],
+    "three": false
+  },
+  "angrybirds": {
+    "open": "_openAngryBirds",
+    "files": [
+      "angrybirds.js"
+    ],
+    "three": false
+  },
+  "quadratic": {
+    "open": "_openQuadratic",
+    "files": [
+      "quadratic.js"
+    ],
+    "three": false
+  },
+  "normaldist": {
+    "open": "_openNormalDist",
+    "files": [
+      "normaldist.js"
+    ],
+    "three": false
+  },
+  "graphtransform": {
+    "open": "_openGraphTransform",
+    "files": [
+      "graphtransform.js"
+    ],
+    "three": false
+  },
+  "pendulum": {
+    "open": "_openPendulum",
+    "files": [
+      "pendulum.js"
+    ],
+    "three": false
+  },
+  "equilibrium": {
+    "open": "_openEquilibrium",
+    "files": [
+      "equilibrium.js"
+    ],
+    "three": false
+  },
+  "opticsbench": {
+    "open": "_openOpticsBench",
+    "files": [
+      "opticsbench.js"
+    ],
+    "three": false
+  },
+  "isoprocess": {
+    "open": "_openIsoprocess",
+    "files": [
+      "isoprocess.js"
+    ],
+    "three": false
+  },
+  "titration": {
+    "open": "_openTitration",
+    "files": [
+      "titration.js"
+    ],
+    "three": false
+  },
+  "probability": {
+    "open": "_openProbability",
+    "files": [
+      "probability.js"
+    ],
+    "three": false
+  },
+  "bohratom": {
+    "open": "_openBohrAtom",
+    "files": [
+      "bohratom.js"
+    ],
+    "three": false
+  },
+  "electrolysis": {
+    "open": "_openElectrolysis",
+    "files": [
+      "electrolysis.js"
+    ],
+    "three": false
+  },
+  "race": {
+    "open": "_openRace",
+    "files": [
+      "race.js"
+    ],
+    "three": false
+  },
+  "waves": {
+    "open": "_openWaves",
+    "files": [
+      "waves.js"
+    ],
+    "three": false
+  },
+  "hydrostatics": {
+    "open": "_openHydro",
+    "files": [
+      "hydrostatics.js"
+    ],
+    "three": false
+  },
+  "radioactive": {
+    "open": "_openRadioactive",
+    "files": [
+      "radioactive.js"
+    ],
+    "three": false
+  },
+  "geometry": {
+    "open": "_openGeometry",
+    "files": [
+      "geometry.js",
+      "triangle.js"
+    ],
+    "three": false
+  },
+  "logic": {
+    "open": "_openLogic",
+    "files": [
+      "logic.js"
+    ],
+    "three": false
+  },
+  "heatengine": {
+    "open": "_openHeatEngine",
+    "files": [
+      "heatengine.js"
+    ],
+    "three": false
+  },
+  "stoichiometry": {
+    "open": "_openStoich",
+    "files": [
+      "stoichiometry.js"
+    ],
+    "three": false
+  },
+  "qualanalysis": {
+    "open": "_openQualAnalysis",
+    "files": [
+      "qualanalysis.js"
+    ],
+    "three": false
+  },
+  "periodic": {
+    "open": "_openPeriodic",
+    "files": [
+      "_periodic_data.js",
+      "periodic.js"
+    ],
+    "three": true
+  },
+  "organic": {
+    "open": "_openOrganic",
+    "files": [
+      "organic.js"
+    ],
+    "three": false
+  },
+  "solutions": {
+    "open": "_openSolutions",
+    "files": [
+      "solutions.js"
+    ],
+    "three": false
+  }
+};
+window.LAB_LAZY_FILES = ["angrybirds.js","bohratom.js","brownian.js","celldivision.js","chemsandbox.js","circuit.js","collision.js","crystal.js","diffusion.js","electrolysis.js","emfield.js","equilibrium.js","flask.js","forcesandbox.js","gas.js","geometry.js","graphtransform.js","heatengine.js","hydrostatics.js","ionexchange.js","isoprocess.js","logic.js","newton.js","normaldist.js","opticsbench.js","orbitals.js","organic.js","pendulum.js","periodic.js","photosynthesis.js","probability.js","projectile.js","quadratic.js","qualanalysis.js","race.js","radioactive.js","reactions.js","redox.js","solutions.js","states.js","stereo.js","stoichiometry.js","titration.js","triangle.js","trigcircle.js","waves.js","_periodic_data.js"];
diff --git a/frontend/lab.html b/frontend/lab.html
index eae2f81..abc74da 100644
--- a/frontend/lab.html
+++ b/frontend/lab.html
@@ -400,71 +400,33 @@
 
 <script src="/js/api.js"></script>
   <script src="/js/sidebar.js"></script>
-<script src="https://cdn.jsdelivr.net/npm/three@0.149.0/build/three.min.js"></script>
+<!-- ════════════════════════════════════════════════════════════════════════
+     Контент-движок, Фаза 3 — ЛЕНИВАЯ ЗАГРУЗКА КОДА СИМУЛЯЦИЙ.
+     На старте грузится только КАРКАС (~360 КБ): реестр, загрузчик, манифест,
+     fx-движки, общие визуалы (_phys_visuals/_chem_visuals/_graph_panel/_util),
+     graph.js (предоставляет GRID для 15 симуляций), lab-init/glue/register-all.
+     Код конкретной симуляции (~2.5 МБ суммарно) и three.js (~600 КБ) грузятся
+     по клику через LabLoader (см. _loader.js + _sim_deps.js). three.js — только
+     для 3D-симуляций (crystal/orbitals/stereo/periodic).
+     ════════════════════════════════════════════════════════════════════════ -->
 <script src="/js/labs/_registry.js"></script>
+<script src="/js/labs/_loader.js"></script>
+<script src="/js/labs/_sim_deps.js"></script>
 <script src="/js/labs/_fx_core.js"></script>
 <script src="/js/labs/_fx_particles.js"></script>
 <script src="/js/labs/_fx_motion.js"></script>
 <script src="/js/labs/_fx_sound.js"></script>
-<script src="/js/labs/graph.js"></script>
-<script src="/js/labs/_phys_visuals.js"></script>
-<script src="/js/labs/emfield.js"></script>
-<script src="/js/labs/triangle.js"></script>
 <script src="/js/labs/_graph_panel.js"></script>
-<script src="/js/labs/projectile.js"></script>
-<script src="/js/labs/collision.js"></script>
-<script src="/js/labs/gas.js"></script>
-<script src="/js/labs/states.js"></script>
-<script src="/js/labs/brownian.js"></script>
-<script src="/js/labs/diffusion.js"></script>
-<!-- coulomb.js removed: merged into emfield.js -->
-<script src="/js/labs/circuit.js"></script>
+<script src="/js/labs/_phys_visuals.js"></script>
 <script src="/js/labs/_chem_visuals.js"></script>
-<script src="/js/labs/reactions.js"></script>
-<script src="/js/labs/flask.js"></script>
-<script src="/js/labs/redox.js"></script>
-<script src="/js/labs/ionexchange.js"></script>
-<script src="/js/labs/stereo.js?v=10"></script>
+<script src="/js/labs/_util.js"></script>
+<script src="/js/labs/graph.js"></script>
 <script src="/js/notifications.js"></script>
 <script src="/js/search.js"></script>
 <script src="/js/mobile.js"></script>
 <script src="/js/labs/lab-init.js"></script>
 <script src="/js/labs/lab-glue.js"></script>
-<script src="/js/labs/newton.js"></script>
-<script src="/js/labs/forcesandbox.js"></script>
-<script src="/js/labs/angrybirds.js"></script>
-<script src="/js/labs/waves.js"></script>
-<script src="/js/labs/chemsandbox.js"></script>
-<script src="/js/labs/stoichiometry.js"></script>
-<script src="/js/labs/celldivision.js"></script>
-<script src="/js/labs/photosynthesis.js"></script>
-<script src="/js/labs/crystal.js"></script>
-<script src="/js/labs/orbitals.js"></script>
-<script src="/js/labs/trigcircle.js"></script>
-<script src="/js/labs/_util.js"></script>
-<script src="/js/labs/quadratic.js"></script>
-<script src="/js/labs/normaldist.js"></script>
-<script src="/js/labs/graphtransform.js"></script>
-<script src="/js/labs/pendulum.js"></script>
-<script src="/js/labs/equilibrium.js"></script>
-    <script src="/js/labs/opticsbench.js?v=10"></script>
-<script src="/js/labs/isoprocess.js"></script>
-<script src="/js/labs/titration.js"></script>
-<script src="/js/labs/probability.js"></script>
-<script src="/js/labs/bohratom.js"></script>
-<script src="/js/labs/electrolysis.js"></script>
-<script src="/js/labs/race.js"></script>
-<script src="/js/labs/hydrostatics.js"></script>
-<script src="/js/labs/radioactive.js"></script>
-<script src="/js/labs/geometry.js"></script>
-<script src="/js/labs/logic.js"></script>
-<script src="/js/labs/heatengine.js"></script>
-<script src="/js/labs/solutions.js" defer></script>
-<script src="/js/labs/organic.js" defer></script>
-<script src="/js/labs/_periodic_data.js" defer></script>
-<script src="/js/labs/periodic.js" defer></script>
-<script src="/js/labs/qualanalysis.js" defer></script>
-<script src="/js/labs/_register-all.js" defer></script>
+<script src="/js/labs/_register-all.js"></script>
 <script>
   /* Sync sound toggle button icon with localStorage state on load */
   (function() {