Opera Anomalies
Every web developer knows that the sky is not always that blue under the W3C standards. As a proof of concept, this page shows you in what respects the Opera browser may show strange behaviour when compared to other ones.
Edit Fields
We don't know why Opera changes border colors of some edit fields.
Buttons
Mouse cursor over button is rendered as arrow despite the CSS 'pointer' attribute, which should look as a hand.
Images
Sometimes, Opera doesn't display images. If you face this problem, try selecting 'Load all images' from Navigation menu. You may have to repeat a few times...
Furthermore, Opera stacks images if the screen resolution is less than 800 x 640 pixels.
Collection of Cascading Style Sheets
Opera doesn't recognize collections of cascading style sheets (document.styleSheets), which could be annoying since other browsers do support them.
Z-index over iframes
Opera doesn't render properly objects over iframes even if their z-indexes are higher.
Tool Tips overdone
Opera forces tool tips over all links. This can be annoying when a tool tip hides useful information on the page. This enforced mechanism does scrap the look & feel of precisely designed web pages despite the intended behaviour of being user-friendly.
Pixels Size on the Macintosh
According to "Tools of the Trade - Cascading Style Sheets: Separating Content from Presentation", by Briggs, Champeon, Costello and Patterson, the Opera browser for the Macintosh assumes that there are about 90 pixels per inch. On a 72dpi screen, characters will then be displayed at 80% of their actual size.
Thanks for communicating any error or omission found in this page.