Card with Animated Border built with Jetpack Compose.

AnimatedBorderCard.kt

// replace outer surface with clipToBounds modifier
@Composable
fun AnimatedBorderCard(
    modifier: Modifier = Modifier,
    shape: Shape = RoundedCornerShape(size = 0.dp),
    borderWidth: Dp = 2.dp,
    gradient: Brush = Brush.sweepGradient(listOf(Color.Gray, Color.White)),
    animationDuration: Int = 10000,
    onCardClick: () -> Unit = {},
    content: @Composable () -> Unit
) {
    val infiniteTransition = rememberInfiniteTransition(label = "Infinite Color Animation")
    val degrees by infiniteTransition.animateFloat(
        initialValue = 0f,
        targetValue = 360f,
        animationSpec = infiniteRepeatable(
            animation = tween(durationMillis = animationDuration, easing = LinearEasing),
            repeatMode = RepeatMode.Restart
        ),
        label = "Infinite Colors"
    )

    Surface(
        modifier = modifier
            .clipToBounds()
            .clickable { onCardClick() }
            .padding(borderWidth)
            .drawBehind {
                rotate(degrees = degrees) {
                    drawCircle(
                        brush = gradient,
                        radius = size.width,
                        blendMode = BlendMode.SrcIn,
                    )
                }
            },
        color = MaterialTheme.colorScheme.surface,
        shape = shape
    ) {
        content()
    }
}
// create a modifier for animated border instead of a composable
@Composable
fun Modifier.animatedBorder(
    backgroundColor: Color = MaterialTheme.colorScheme.surface,
    borderWidth: Dp = 2.dp,
    gradient: Brush = Brush.sweepGradient(listOf(Color.Gray, Color.White)),
    animationDuration: Int = 10000,
) = composed {
    val infiniteTransition = rememberInfiniteTransition(label = "Infinite Color Animation")
    val degrees by infiniteTransition.animateFloat(
        initialValue = 0f,
        targetValue = 360f,
        animationSpec = infiniteRepeatable(
            animation = tween(durationMillis = animationDuration, easing = LinearEasing),
            repeatMode = RepeatMode.Restart
        ),
        label = "Infinite Colors"
    )
    clipToBounds()
        .padding(borderWidth)
        .drawBehind {
            rotate(degrees = degrees) {
                drawCircle(
                    brush = gradient,
                    radius = size.width,
                    blendMode = BlendMode.SrcIn,
                )
            }
        }
        .background(backgroundColor)
}