why are all the strings of Netflix's css not valid?

Question

While looking at the code of some sites including Netflix and W3Schools, I noticed something odd: when looking at some elements (by clicking Inspect Element in Firefox Developer Edition), almost all of the CSS rules/strings were crossed out. Why would that be? I attached two screenshots, 1 shows many crossed lines and 2 shows what element I was expecting.1 2

They use `Vendor Prefix` for browsers compatibility (Chrome, firefox, mozila etc). In case one fails the other will take place. https://developer.mozilla.org/en-US/docs/Glossary/Vendor_Prefix — Mike Trinh, Jan 22 '18 at 16:44

score 2 · Accepted Answer · answered Jan 22 '18 at 16:44

2

The majority of those rules crossed out are fallbacks for specific browsers.

-webkit is Chrome and Safari, -moz is Firefox, -o is Opera and -ms for Internet Explorer.

answered Jan 22 '18 at 16:44

Sam Johnson

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Interesting! How can I see which of those it is? And where are the rules that **are** written with -moz? – dekzok Jan 22 '18 at 19:18

score 0 · Answer 2 · answered Jan 22 '18 at 16:51

Crossed out does not mean invalid, but not applied. That a value is not applied could be because it is not valid, or because it is overwritten by an other rule.

The values for left and right are valid, but they are not applied, because they are overwritten by another rule.

why are all the strings of Netflix's css not valid?

2 Answers2