conic-gradient and linear-gradient

of what this code does.

import { useRef, useState, useEffect } from "react";

export const InputSpotlightBorder = () => {
  const boxRef = useRef(null);

  useEffect(() => {
    const boxElement = boxRef.current;

    if (!boxElement) {
      return;
    }

    const updateAnimation = () => {
      const angle =
        (parseFloat(boxElement.style.getPropertyValue("--angle")) + 3) % 360;
      boxElement.style.setProperty("--angle", `${angle}deg`);
      requestAnimationFrame(updateAnimation);
    };

    requestAnimationFrame(updateAnimation);
  }, []);

  return (
    <input
      ref={boxRef}
      style={{
        "--angle": "0deg",
        "--border-color": "conic-gradient(from var(--angle), #111, #eee)",
        "--bg-color": "linear-gradient(#111, #111)",
      }}
      placeholder="What do you want to do?"
      className="my-8 flex w-60 items-center justify-center rounded-full border-2 border-slate-700/40 p-3 [background:padding-box_var(--bg-color),border-box_var(--border-color)] focus:outline-none text-slate-500"
    ></input>
  );
};

Explanation:
This code defines a custom input component called InputSpotlightBorder, which creates an animated border effect using CSS gradients. The useRef hook is used to reference the input element, and the useEffect hook is used to start the animation when the component is mounted.

The animation is created by updating the --angle CSS variable in the boxElement style. The updateAnimation function is called repeatedly using requestAnimationFrame to increment the angle by 3 degrees each time, creating a rotating effect.

The border-color is set to a conic-gradient instead of linear-gradient to create a more circular border effect. The --angle variable is used to animate the gradient, so that it rotates along with the border.

The --bg-color is set to a linear-gradient to create a solid background color for the input. The className combines the background and border gradients using the background property, and also sets some additional styles for the input element.