The default htmlArea RTE in TYPO3’s backend renders the textarea content in a pretty ugly fashion. It looks like in the HTML 1.0 ages. But you can change that using just a few lines of code and a css file. How to accomplish this you might wonder. Its easy.
Go edit your root page (or some other page if you want to do this only on a page) and in the Options tab there is a TSconfig field, now just paste the following code there:
RTE.default {
contentCSS = fileadmin/templates/styles/rte.css
}
Now you just be sure to have a rte.css file in the specified location (fileadmin/templates/styles) and you can put there your css definitions for the RTE text. This way you can match the RTE’s look and feel with your site’s design.
Example:
Before using CSS for RTE
After using CSS for RTE