80: Animating to and from top-layer

In this episode Una and Adam continue talking about dialogs and popovers, but this time it's all about animating them into and out of the top layer.. We'll be introducing starting-style, a new mode for transitioning discrete properties, and the overlay property for smooth entry and exit animations.  Links: top-layer CSS spec → https://goo.gle/4c2elUW Four new CSS features for smooth entry and exit animations by Una → https://goo.gle/3KpyB7e Using @starting-style and transition-behavior for enter and exit stage effects → https://goo.gle/452FG7p Popover on MDN → https://goo.gle/453xfss :popover-open on MDN → https://goo.gle/3x5XLVl Dialog and popover animated → https://goo.gle/3Kn1Ck7 Popover animated with nesting → https://goo.gle/3wW3Qns What is the top layer? → https://goo.gle/457rUjQ overlay property on MDN → https://goo.gle/3yKNRsT MDN demos → https://goo.gle/4c2eIyO Una Kravets (co-host) Twitter | Instagram | YouTube Making the web more colorful ✨🎨  Web DevRel @googlechrome Unicorn face host of @toolsday & Designing in the Browser 🎬  Adam Argyle (co-host) Twitter | Instagram | YouTube @GoogleChrome CSS DevRel; @CSSWG; VisBug maker; punk; CSS/JS/UX addict; 💀🤘