Challenge 1: A Composable with Parameters — Solution

@Composable
fun ProductCard(name: String, price: Double) {
    Column(modifier = Modifier.padding(16.dp)) {
        Text(text = name, fontSize = 18.sp)
        Text(text = "$$price", color = Color.Gray)
    }
}

@Preview(showBackground = true)
@Composable
fun ProductCardPreview() {
    ProductCard(name = "Keyboard", price = 49.99)
}

// MainActivity.kt
class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            ProductCard(name = "Keyboard", price = 49.99)
        }
    }
}

Notes:
- ProductCard takes two plain parameters (name, price) exactly like any
  regular Kotlin function — @Composable doesn't change how parameters
  work, only that the function can call other composables (Column, Text)
  inside it.
- ProductCardPreview takes no parameters and simply calls ProductCard
  with sample data — this is the standard shape for a @Preview function,
  letting Android Studio render it in the editor without running the app
  at all.
- setContent { } in MainActivity replaces Course 1's
  setContentView(R.layout.activity_main) entirely — there's no XML
  layout file involved for this screen.