How to use HTML or CSS in Android Studio?

I would like to know how I can structure my app with HTML, and style it with CSS too. I want to put a fieldset to form a table. I looked for tutorials on the internet but I did not quite understand how to use it.

I want the lvDolar, from the XML below, to be bypassed by a fieldset:

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    tools:context="com.example.teste.application.VerDolar"
    android:background="@color/white">

    <ListView
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        **android:id="@+id/lvDolar"**
        android:layout_alignParentBottom="true"
        android:layout_alignParentStart="true"
        android:layout_marginBottom="0dp" />
</RelativeLayout>

This is my java class:

package teste;

import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.ArrayAdapter;
import android.widget.ListView;

import com.example.rainah.application.R;

import java.util.List;


public class VerDolar extends ActionBarActivity {

    private ListView lvDolar;
    private List<Dolar> dolar;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_ver_dolar);
        setTitle("Dolar");

        lvDolar = (ListView) findViewById(R.id.lvDolar);
    }

    @Override
    protected void onResume() {
        super.onResume();

        DbHelper db = new DbHelper(this);
        List<Dolar> listDolar = db.selectDolar();

        ArrayAdapter<Dolar> list = new ArrayAdapter<Dolar>(this, android.R.layout.simple_list_item_1, listDolar);

        lvDolar.setAdapter(list);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.menu_ver_dolar, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        //int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        switch(item.getItemId()) {
            case R.id.action_search:
                break;
            case R.id.action_new:
                Intent intent = new Intent(this, AddDolar.class);
                startActivity(intent);
                break;
            default:
                return true;
        }
        return super.onOptionsItemSelected(item);
    }
}

Thanks, if anyone can help me, because I think it's a relatively simple question, but I'm breaking my heart to understand how this works in android studio. Thanks in advance.