Increasing font size on Windows help file (CHM)

I just found that increasing the text size in IE, and then reopening the CHM document increases the font size within the CHM document.

"Actually just like in IE, Ctrl++, Ctrl+-, and Ctrl+0 still work as ""zoom"" hot keys, even though this is not apparent in the UI.

(I've tried to update the popular answer to clarify this.)"

"I think it's an option the creator of the CHM specifies. In an old job we used to supply our help files as CHM (among other formats) and I'm sure that there was an option we had to set to get the ""change font size"" on the toolbar.

I've just opened one of the files and the option's still there and it works. Unfortunately I don't have access to the tool we used at the moment so I can't check."

"You may create a CSS file defining desired font size and specify it in Internet Explorer properties: Styling -> Use user-defined style-sheets.

*
{
font-size: 30px;
}"