Demonstration of background image problems 5. Parsing Opera's CSS parser has a major fault in the error recovery code. This causes documents designed for levels of the CSS specification not yet supported by the browser to render incorrectly. Demonstration of problems with error handling 6. Vertical Formatting Bugs Opera has problems with vertical formatting that cause web pages to display incorrectly.
Opera also handles line height incorrectly because it misinterprets the definition of font size.
The font size is the height from the bottom of the lowest letter to the top of the highest letter, and therefore characters should never overlap if they are in a paragraph with the line height set to one. This does not happen in Opera. There is slight overlap between descenders and accent marks. There are a few different problems with the interpretation of the selector syntax, the assignment of specificity and the sorting of the cascade. This set of problems is less visible than the others, but that does not imply that they are any less important.