How do I set multiple font sizes within a single announcement message?

You can change the font-size of parts of your message in the Quick Announcement Bar by adding style tags (HTML code) in the message. Simply place any text you want resized inside <span> tags with styling code.

For example, this resizes part of the message to a font-size of 24px: 

In the Message field:

“First part of message <span style="font-size: 24px;">Large Text!!</span> and back to small text“

The result:​​

The font size in the first and last parts of the message, as well as the button, is set in the Style Configuration → Font Size