<noscript> tag for content is the lack of control we have over the display, it is entirely controlled by the browser and, according to some reports, may not be reliable in all browsers.
<html> element to provide additional styling.
Cutting The Mustard
<html> element to allow us to style elements.
When adding content in this manner it is important to conciser the SEO implications, you should try and place any content messages towards the bottom of the page if at all possible. If the warning messages are the first thing on the page then they may appear as the snippet in Google search results.
Bringing it all together
Shown below is an outline of an HTML page that includes practical examples of the various techniques discussed above. You can also see the CSS techniques in action in this mini web-thing (source on GitHub).
Sample HTML page
<noscript>for functionality (such as analytics).
- Use CSS hooks to provide alternative content.
- Keep SEO implications in mind.