roly | A comparison of various moving window median algorithms | Learning library

I am trying to mimic the CSS animations from a website here: https://stanographer.com/

I want to copy the way the site:

• starts by showing a full screen black div sliding away to the right

• "loads" the black background (div tags) behind text (as in "Hi, I'm Stanley Sakai"), expanding left to right and

  • "loads" the text over the black background div, expanding left to right.

Now you might ask, "Why not just inspect the page, look at the classes on the divs and text, then inspect the CSS sheet in the network tab?" And I've tried that. The CSS looks weird. My friend said it is pre-processed by SASS, whatever that means. Anyway, I cannot decipher the code.

I've been to a few different StackOverflow pages (here's one) & over a dozen different pages on Google. I learned about using keyframes but I haven't figured out how to recreate the effect on Stanographer.com. My friend, who owns the website, also provided this example, but I don't get how to apply it to individual divs. He said something about using the z-index but I just don't see it.

I know that to make the page start with a full black screen & then slide out, I have to trigger a class change using JavaScript. I have:

I am in the process of creating a sh code for masking the sensitive data using AWK function in AIX server.