The “Cascading Style Sheets” (CSS) are a method to implement styling in HTML which is a big step forward from inline "style" declarations, allowing for greater flexibility.

The styles from CSS can be applied to any type of selection (text, image, table). If you want to set or change the CSS style for a text, you can either select the text (or only the part of text for which you want to set a CSS) or place the cursor inside the text and then choose a CSS style from the CSS dropdown menu in the toolbar. The style will be set to the selected part of the text. In case you have just placed the cursor inside a text, if this text does not have a style defined yet (his CSS is set to None), the CSS style will be set to it and also to all the text in the paragraph which has not a style defined. If the text in which the cursor is placed has an already set CSS style, the new style will be set to it and also to all the text in the paragraph which is included in the same CSS style tag (a SPAN tag) with your text. This is a very useful feature because the user doesn't have to spend time making text selections and identifying styles.

Note: In order to obtain good results, user should set the CSS styles to the text in an accurate manner, rather than making repeated selections on the text and changing the style several times. This method is not recommended, especially when using the Mozilla browser, because the HTML code will get too complicated and the visual results will not always be the expected ones. To manage the CSS styles correctly, user can also use the Tag Selector in order to easily select and remove some SPAN tags (corresponding to already set CSS styles) from the code.