How to increase the width of the horizontal line using Markdown on GitHub

Instead of using *** or ---, try:

<hr style="border:2px solid gray"> 

From the cheatsheet

Three or more...

Hyphens

---

Asterisks

***

Underscores

___

give you the same thing, which is the standard horizontal line.

You cannot style markdown, you get what you get. Github chooses the style.

You can add a thinner line than the normal one by simply writing an empty heading #

Example:

Use:

<hr style="border:2px solid blue"> 

Here the colour of the line has been changed as well. This method uses standard HTML markup and works much better than just "***".