diff --git a/frontend/text-editor/src/editor/controllers/SelectionController.js b/frontend/text-editor/src/editor/controllers/SelectionController.js
index d5c5ad7db4..8c98662396 100644
--- a/frontend/text-editor/src/editor/controllers/SelectionController.js
+++ b/frontend/text-editor/src/editor/controllers/SelectionController.js
@@ -278,19 +278,30 @@ export class SelectionController extends EventTarget {
       // FIXME: I don't like this approximation. Having to iterate nodes twice
       // is bad for performance. I think we need another way of "computing"
       // the cascade.
-      for (const textNode of this.#textNodeIterator.iterateFrom(
-        startNode,
-        endNode,
-      )) {
+      const textNodesInRange = [
+        ...this.#textNodeIterator.iterateFrom(startNode, endNode),
+      ];
+      for (const textNode of textNodesInRange) {
         const paragraph = textNode.parentElement.parentElement;
         this.#applyStylesFromElementToCurrentStyle(paragraph);
       }
-      for (const textNode of this.#textNodeIterator.iterateFrom(
-        startNode,
-        endNode,
-      )) {
-        const textSpan = textNode.parentElement;
-        this.#mergeStylesFromElementToCurrentStyle(textSpan);
+      // Empty trailing text runs (length 0) often carry paragraph fallback styles
+      // (e.g. font-size 0) and are not user-visible; merging them with real text
+      // yields false "mixed" in the sidebar. Skip empty nodes when the selection
+      // also includes non-empty text; if everything is empty, keep prior behavior.
+      const nonEmptyTextNodes = textNodesInRange.filter(
+        (textNode) => textNode.length > 0,
+      );
+      const spanMergeNodes =
+        nonEmptyTextNodes.length > 0 ? nonEmptyTextNodes : textNodesInRange;
+
+      if (spanMergeNodes.length > 0) {
+        const firstTextSpan = spanMergeNodes[0].parentElement;
+        this.#applyStylesFromElementToCurrentStyle(firstTextSpan);
+        for (let i = 1; i < spanMergeNodes.length; i++) {
+          const textSpan = spanMergeNodes[i].parentElement;
+          this.#mergeStylesFromElementToCurrentStyle(textSpan);
+        }
       }
     }
     return this;
diff --git a/frontend/text-editor/src/editor/controllers/SelectionController.test.js b/frontend/text-editor/src/editor/controllers/SelectionController.test.js
index 076db92f41..5d5b4a7c8c 100644
--- a/frontend/text-editor/src/editor/controllers/SelectionController.test.js
+++ b/frontend/text-editor/src/editor/controllers/SelectionController.test.js
@@ -4,7 +4,7 @@ import {
   createParagraph,
   createParagraphWith,
 } from "../content/dom/Paragraph.js";
-import { createTextSpan } from "../content/dom/TextSpan.js";
+import { createTextSpan, createVoidTextSpan } from "../content/dom/TextSpan.js";
 import { createLineBreak } from "../content/dom/LineBreak.js";
 import { TextEditorMock } from "../../test/TextEditorMock.js";
 import { SelectionController } from "./SelectionController.js";
@@ -1683,6 +1683,54 @@ describe("SelectionController", () => {
     expect(selectionController.focusAtEnd).toBeTruthy();
   })
 
+  test("`currentStyle` ignores empty text nodes when merging span styles (no false mixed font-size)", () => {
+    const textEditorMock = TextEditorMock.createTextEditorMockWithParagraphs([
+      createParagraph([
+        createTextSpan(new Text("Hello"), { "font-size": "50" }),
+        createVoidTextSpan({ "font-size": "0" }),
+      ]),
+    ]);
+    const root = textEditorMock.root;
+    const paragraph = root.firstChild;
+    const firstTextNode = paragraph.firstChild.firstChild;
+    const lastTextNode = paragraph.firstChild.nextSibling.firstChild;
+    const selection = document.getSelection();
+    const selectionController = new SelectionController(
+      textEditorMock,
+      selection,
+    );
+    textEditorMock.element.focus();
+    selection.setBaseAndExtent(firstTextNode, 0, lastTextNode, 0);
+    document.dispatchEvent(new Event("selectionchange"));
+    expect(selectionController.currentStyle.getPropertyValue("font-size")).toBe(
+      "50px",
+    );
+  });
+
+  test("`currentStyle` stays mixed when two non-empty spans have different font sizes", () => {
+    const textEditorMock = TextEditorMock.createTextEditorMockWithParagraphs([
+      createParagraph([
+        createTextSpan(new Text("Hello"), { "font-size": "50" }),
+        createTextSpan(new Text("World"), { "font-size": "36" }),
+      ]),
+    ]);
+    const root = textEditorMock.root;
+    const paragraph = root.firstChild;
+    const firstTextNode = paragraph.firstChild.firstChild;
+    const lastTextNode = paragraph.firstChild.nextSibling.firstChild;
+    const selection = document.getSelection();
+    const selectionController = new SelectionController(
+      textEditorMock,
+      selection,
+    );
+    textEditorMock.element.focus();
+    selection.setBaseAndExtent(firstTextNode, 0, lastTextNode, 5);
+    document.dispatchEvent(new Event("selectionchange"));
+    expect(selectionController.currentStyle.getPropertyValue("font-size")).toBe(
+      "mixed",
+    );
+  });
+
   test("`currentStyle` uses text span font-size when anchor is paragraph (Firefox-style word selection)", () => {
     const textEditorMock = TextEditorMock.createTextEditorMockWithParagraphs([
       createParagraph([