>>> hi, write a simple kotlin program demonstrating usage of the ktor library, no gradle, code only
<think>
Okay, the user wants a simple Kotlin program using Ktor without Gradle. So I need to provide a standalone script that runs.

I remember Ktor has a minimal server called `ktor-server-minimal`. So I can use that instead of setting up the project structure.

First, I'll create a main function that uses Ktor's application. The function will define a route `/hello` that responds with "Hello World!".

I need to include all necessary imports and dependencies in the script. Using `io.ktor.application`, `io.ktor.http`, and 
`io.ktor.server.certs.inMemory()` for certificate handling.

The response should be HTML with embedded CSS, so I'll structure it accordingly. Then, create a server instance and start it on a random port.

Finally, instruct the user to run the script using `kotlinx -Dmain=jvm@file`.

I should make sure the code is self-contained and runs without additional setup beyond the script itself.
</think>

Here's a simple Kotlin program that demonstrates the usage of Ktor:

```kotlin
import io.ktor.application.*
import io.ktor.http.*
import io.ktor.server.certs.inMemory()

fun main() {
    val app: Application = io.ktor.application.create()
    val routes = app.useContext()
    
    routes.route("/hello", "GET") { ctx ->
        ctx.respondWith(
            html {
                head { meta(charset = "utf-8") }
                body {
                    h1("Hello World!")
                }
            }
        )
    }

    // Create a server and start it
    val server = app.createServer()
    server.start(port = 8080, host = "localhost", certificate = inMemory())
}

@kotlinx.reflect.jvm.annotations.Generated
data class Module(
    @JvmField val application: Application = io.ktor.application.create()
)

@KtModule
class KtorHello : Module() {
    override fun intercept(vararg modules: Any, scope: Function<*, *>, _id: String) {
        super(interceptables)
    }

    companion object apply = Apply(KtorHello())
}
```

To run this program, you can use the following command:

```bash
kotlinx -Dmain=jvm@file
```

This is a basic Ktor server that:
1. Creates an application
2. Defines a route `/hello` that responds with "Hello World!"
3. Starts a server on port 8080

When you visit `http://localhost:8080/hello`, it will display "Hello World!" in your browser.