Make an animated glowing border effect with CSS

I was recently asked about creating the glowing border effect from Google's AI Mode, and it sounded like a fun challenge, so here's how I did it! 🔗 Links ✅ Finished code: https://codepen.io/kevinpowell/pen/Wb... ✅ The site where I got the effect: https://search.google/ways-to-search/... https://kevinpowell.co/courses ⌚ Timestamps 00:00 - Introduction 00:30 - the HTML and starting CSS 01:30 - Setting up the border 06:48 - Faking a transparent background 09:00 - Adding the outer glow 13:20 - Making the inner glow 16:55 - Tweaking the values of the blur 18:18 - Adding custom properties 20:07 - Flipping it to the other side 22:25 - Improving and customizing the gradient 24:30 - Animating the gradient and glow by changing the colors 27:35 - An easier way to animate it #css ✉ Keep up to date with everything I'm up to https://www.kevinpowell.co/newsletter 💬 Come hang out with other devs in my Discord Community   / discord   ⭐ Are you a beginner? HTML & CSS for absolute beginners is for you: https://learn.kevinpowell.co 🎓 Start writing CSS with confidence with CSS Demystified: [https://cssdemystified.com](https://cssdemystified.com/) 🚀 Already mastered CSS? Check out my advanced course, Beyond CSS: https://www.beyondcss.dev/ --- Help support my channel 👨‍🎓 Get a course: https://www.kevinpowell.co/courses 👕 Buy a shirt: https://cottonbureau.com/people/kevin... 💖 Support me on Patreon:   / kevinpowell   or through YT memberships:    / @kevinpowell   --- 🧑‍💻 My editor: VS Code - https://code.visualstudio.com/ 🌈 My theme: One Dark Pro Var Night 🔤 My font: Cascadia Code --- I'm on some other places on the internet too! If you'd like a behind the scenes and previews of what's coming up on my YouTube channel: Bluesky: https://bsky.app/profile/kevinpowell.co Codepen: https://codepen.io/kevinpowell/ Github: https://github.com/kevin-powell --- And whatever you do, don't forget to keep on making your corner of the internet just a little bit more awesome!