How to create a moving border effect with Tailwind CSS

Recently, I came across a cool effect which appears to be a border that rotates and moves around the card. I thought it would be a great effect to add to my projects, helping buttons and cards to stand out. So, I decided to create a tutorial on how to create this effect with Tailwind CSS only. Here's a preview of what we are going to create with just Tailwind CSS.

Code explanation

Basically we have 3 moving parts here:

1. The outer container which contains the input and the button elements.
2. An absolutely positioned div that acts as the background moving border.
3. The inside elements which are input and buttons. The meaty part is the absolutely positioned div. Let's take a look at the code snippet

<div class="mx-auto flex w-full max-w-lg items-center justify-center">
  <div
    class="relative z-10 flex w-full cursor-pointer items-center overflow-hidden rounded-xl border border-slate-800 p-[1.5px]"
  >
    <div
      class="animate-rotate absolute inset-0 h-full w-full rounded-full bg-[conic-gradient(#0ea5e9_20deg,transparent_120deg)]"
    ></div>
    <div class="relative z-20 flex w-full rounded-[0.60rem] bg-slate-900 p-2">
      <input
        type="text"
        class="mr-2 inline-block h-full flex-1 rounded-lg bg-transparent px-2 py-3 text-gray-500 placeholder:text-slate-700 focus:outline-none focus:ring-1 focus:ring-cyan-500"
        placeholder="subscribe to our newsletter"
      />
      <span
        class="relative z-50 block rounded-lg border border-slate-800 bg-slate-900 px-8 py-3 text-center text-sm text-white shadow-2xl transition duration-200 hover:bg-slate-800"
      >
        Subscribe
      </span>
    </div>
  </div>
</div>

/** @type {import('tailwindcss').Config} */
module.exports = {
  theme: {
    extend: {
      animation: {
        rotate: "rotate 10s linear infinite",
      },
      keyframes: {
        rotate: {
          "0%": { transform: "rotate(0deg) scale(10)" },
          "100%": { transform: "rotate(-360deg) scale(10)" },
        },
      },
    },
  },
  plugins: [],
};

Here, the meaty snippet is

<div
  class="animate-rotate absolute inset-0 h-full w-full rounded-full bg-[conic-gradient(#0ea5e9_20deg,transparent_120deg)]"
></div>

The outer container is positioned relative so that the inner absolutely positioned div can be positioned absolute relative to the outer container. We apply a conic-gradient to the div, which goes from blue to transparent. This is the moving border effect that we animate with keyframes

keyframes: {
  rotate: {
    "0%": { transform: "rotate(0deg) scale(10)" },
    "100%": { transform: "rotate(-360deg) scale(10)" },
  },
},

The rotate property makes it go from 0 to 360 degrees in 10 seconds. The scale property makes it go from 10 to 10. This is what makes the border move around the card.

Conclusion

I hope you enjoyed this tutorial. If you have any questions, feel free to ask them on twitter. I'm @mannupaaji on twitter.