app-theme.kt

// Theme.kt

@Composable
fun AppTheme(
    useDarkTheme: Boolean = isSystemInDarkTheme(),
    theme: Theme? = null,
    content: @Composable () -> Unit,
) {
    val colors = when (theme) {
        Theme.Dark -> DarkColors
        Theme.Light -> LightColors
        Theme.HighContrast -> HighContrast
        null -> if (!useDarkTheme) {
            LightColors
        } else {
            DarkColors
        }
    }
    MaterialTheme(
        colorScheme = colors,
        content = content,
    )
}