CSS背景技术遇到问题

Question

I was working on a blur effect That is used in icloud.com website. i have found the blur effect but there was something that i didn't see before. those were some background properties: This Background Property Was Used For Blurring:

background-image: -webkit-canvas(blurredDerivativeForButtonsc2094_at_28px);

What Is This "-webkit-canvas" ? how it Works?

And This is For making A gradient Background:

background: url("data:image/png;base64,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");

And What is This Loooooooong Code For Background?

Answer 1

That looooooooong code for the background is a base64 encoded image, it's a way of embedding image data directly in the webpage.

The webkit-canvas is a webkit only tag, so it only supports chrome and safari. There isn't that much point in learning browser specific CSS as a beginner.