diff --git a/demo/smoke_icon_scale.mjs b/demo/smoke_icon_scale.mjs
new file mode 100644
index 0000000..e2a5f17
--- /dev/null
+++ b/demo/smoke_icon_scale.mjs
@@ -0,0 +1,38 @@
+// Множитель «размер значка» обязан масштабировать ГЛИФ вместе с подложкой:
+// --mdc-icon-size считался от базового --icon-size, и «увеличенный» значок
+// был пустой рамкой вокруг дефолтной иконки (репорт пользователя, 2026-07-29).
+import { launch, checkAll, finish } from './serve.mjs';
+const { page, browser } = await launch();
+const out = await page.evaluate(async () => {
+  const o = {};
+  const c = window.__card;
+  const sr = () => c.shadowRoot || c.renderRoot;
+  const d = c._devices.find((x) => x.space === 'f1' && x.bindingKind === 'device');
+  const glyphW = () => {
+    const el = [...sr().querySelectorAll('.dev')].find((e) => !e.classList.contains('ghost'));
+    const ic = el?.querySelector('ha-icon');
+    return ic ? ic.getBoundingClientRect().width : 0;
+  };
+  const badgeW = () => {
+    const el = [...sr().querySelectorAll('.dev')].find((e) => !e.classList.contains('ghost'));
+    return el ? el.getBoundingClientRect().width : 0;
+  };
+  // базовый размер
+  const g1 = glyphW(), b1 = badgeW();
+  // множитель ×3 на всех авто-устройствах через маркер первого
+  c._serverCfg.markers = (c._serverCfg.markers || []).filter((m) => m.id !== d.id);
+  c._serverCfg.markers.push({ id: d.id, binding: 'device:' + d.bindingRef, size: 3 });
+  c._cfgEpoch++; c._regSignature = '';
+  c._maybeRebuildDevices(); c.requestUpdate(); await c.updateComplete;
+  await new Promise((r) => setTimeout(r, 100));
+  const scaled = [...sr().querySelectorAll('.dev')].find((e) => (e.getAttribute('style') || '').includes('--dev-scale:3'));
+  const g3 = scaled?.querySelector('ha-icon')?.getBoundingClientRect().width || 0;
+  const b3 = scaled?.getBoundingClientRect().width || 0;
+  o.badgeScales = b3 > b1 * 2.5;
+  o.glyphScalesWithBadge = g3 > g1 * 2.5; // раньше глиф оставался базовым
+  o.glyphFillsBadge = g3 / b3 > 0.45 && g3 / b3 < 0.8; // пропорция сохранена
+  c._serverCfg.markers = c._serverCfg.markers.filter((m) => m.id !== d.id);
+  c._cfgEpoch++; c._regSignature = ''; c._maybeRebuildDevices();
+  return o;
+});
+await finish(browser, checkAll(out));
diff --git a/demo/srv/assets/houseplan-card.js b/demo/srv/assets/houseplan-card.js
index 0109c0b..cfaa3f2 100755
--- a/demo/srv/assets/houseplan-card.js
+++ b/demo/srv/assets/houseplan-card.js
@@ -942,7 +942,11 @@ const t=globalThis,e=t.ShadowRoot&&(void 0===t.ShadyCSS||t.ShadyCSS.nativeShadow
       z-index: 2;
     }
     .dev ha-icon {
-      --mdc-icon-size: calc(var(--icon-size, 2.5cqw) * 0.62);
+      /* from --dev-size, NOT --icon-size: the per-device size multiplier must
+         scale the GLYPH with its badge. Pinned to the base size, "make this
+         icon bigger" grew an empty box around a default-size glyph (user
+         report via the owner, 2026-07-29). */
+      --mdc-icon-size: calc(var(--dev-size, var(--icon-size, 2.5cqw)) * 0.62);
       display: flex;
       align-items: center;
       justify-content: center;
diff --git a/dist/houseplan-card.js b/dist/houseplan-card.js
index 0109c0b..cfaa3f2 100755
--- a/dist/houseplan-card.js
+++ b/dist/houseplan-card.js
@@ -942,7 +942,11 @@ const t=globalThis,e=t.ShadowRoot&&(void 0===t.ShadyCSS||t.ShadyCSS.nativeShadow
       z-index: 2;
     }
     .dev ha-icon {
-      --mdc-icon-size: calc(var(--icon-size, 2.5cqw) * 0.62);
+      /* from --dev-size, NOT --icon-size: the per-device size multiplier must
+         scale the GLYPH with its badge. Pinned to the base size, "make this
+         icon bigger" grew an empty box around a default-size glyph (user
+         report via the owner, 2026-07-29). */
+      --mdc-icon-size: calc(var(--dev-size, var(--icon-size, 2.5cqw)) * 0.62);
       display: flex;
       align-items: center;
       justify-content: center;
diff --git a/docs/TESTING.md b/docs/TESTING.md
index 74e75a7..aefd6e5 100644
--- a/docs/TESTING.md
+++ b/docs/TESTING.md
@@ -244,6 +244,9 @@ Run the *core flows* (marked ★ below) in each environment at least once per mi
       at 70% of a device icon and zooming WITH the plan; the small metric rows
       under the room name now show in the plan editor too
       [auto: smoke_room_cards gearDetached/plainInPlan]
+- [ ] Icon size multiplier scales the glyph (dev): set a marker's size to 3 —
+      the icon inside grows with the badge instead of staying default
+      [auto: smoke_icon_scale]
 - [ ] Auto-grid parity (v1.51.2, HP-1511-01): with an empty layout, a visible
       device among hidden ones sits at the same spot on both cards
       [auto: smoke_hidden_flag autoGridParity]
diff --git a/src/styles.ts b/src/styles.ts
index 0e1747e..b2e8ff0 100644
--- a/src/styles.ts
+++ b/src/styles.ts
@@ -939,7 +939,11 @@ export const cardStyles = css`
       z-index: 2;
     }
     .dev ha-icon {
-      --mdc-icon-size: calc(var(--icon-size, 2.5cqw) * 0.62);
+      /* from --dev-size, NOT --icon-size: the per-device size multiplier must
+         scale the GLYPH with its badge. Pinned to the base size, "make this
+         icon bigger" grew an empty box around a default-size glyph (user
+         report via the owner, 2026-07-29). */
+      --mdc-icon-size: calc(var(--dev-size, var(--icon-size, 2.5cqw)) * 0.62);
       display: flex;
       align-items: center;
       justify-content: center;