Ahmad Shadeed digs around the new Facebook’s front-end code.

One that stood out to me:

.element {
  inset: 4px 0;
  /* Which is equivalent to: top: 4px, bottom: 4px, left: 0, right: 0 */
}

Whaaat? This is the first I’ve heard of the inset property. Ahmad said he saw it working in Chrome 80, but it definitely isn’t for me (nor Safari). It does in Firefox though.

It’s shorthand for top/right/bottom/left (just like margin, in a sense), which is certainly welcome if you ask me. Bring on the support.

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If you’re into people digging into big sites to learn stuff…

• Elad Shechter recently wrote Reverse Engineering WhatsApp Web’s CSS.
• Tee Diang Reverse Engineered Twitch.tv UI

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