Editor and page don't match

Hello,

My question is very simple. ??

This is the code: https://oi60.tinypic.com/5cd9o4.jpg
This is how it looks in the visual editor: https://oi58.tinypic.com/afamig.jpg
This is how it looks when I load the page in Firefox: https://oi62.tinypic.com/9tldgn.jpg

They don’t match, so I’m doing something wrong. Could someone help me on this?

Thanks in advance! ??