Css validation makes sure all your style sheets conform to the standards, making sure your site works well with all browsers now & in the future.
The same reasons to validate html also apply to css:
DeepTrawl uses the css validator developed by the w3c, so you know it's the best available. The difference between DeepTrawl and other validators is that it checks more than the css in one file. DeepTrawl checks all the inline css in your html pages plus internal and external style sheets with just one click. Like every other check our css validator trawls your whole site, validating all the css it finds.
The results are shown file by file so you always know exactly where the errors are. You can also use the integrated editor to highlight the exact cause of errors.
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