How to change the width of a spreadsheet report?

How to change the width of a spreadsheet report?

I have a report with display type as spreadsheet.
As we know, we can change the width column in List-Grid display type. What about spreadsheets? There is no menu 'change column width'.
Maybe with a 'hack' CSS way in a HTML report?

UPDATE from Manual
The options to Add, Modify and Delete records will be displayed only if the Edit permissions are provided for this report, by the application owner. A Spreadsheet report does not support Set Grouping, Custom Action, Record Summary and Set Column Widths.