With custom css style, the current cursor position is offscreen in preview pane

With custom css style (I increased font-size for headings), the current cursor position is offscreen in the preview pane.

I am not sure if this is the same issue as https://github.com/MacDownApp/macdown/issues/983.

Please check my screenshot:


**Edited:** I just found out the cursor is not included in the screenshot. The cursor is at the end of the Editor Pane.

No source files, tests, or entry points are identified. Reproduce the cursor-position problem in the preview pane with custom CSS that increases heading font size, compare it with issue #983, and confirm that the cursor remains visible at the corresponding position.

Written by the indexing model from the issue text.