Praxe pro zarovnání textu v CSS

Zkopírujte si následující HTML kód a vyřešte pro něj uvedené úkoly:

html<h1>Main page title</h1>
<table border="1">
  <tr>
    <th>Product</th>
    <th>Price</th>
    <th>Quantity</th>
  </tr>
  <tr>
    <td>Apples</td>
    <td>100</td>
    <td>5kg</td>
  </tr>
  <tr>
    <td>Oranges</td>
    <td>200</td>
    <td>6kg</td>
  </tr>
  <tr>
    <td>Bananas</td>
    <td>300</td>
    <td>7kg</td>
  </tr>
</table>

<h2>Secondary heading 1</h2>
<p>
  Lorem ipsum dolor sit amet, consectetur adipiscing elitorire
  aenean a dapibus magna, ac interdum nisl. Suspendisse egetil
  fringilla nibh, eu commodo arcu. Donec lacinia tempor velite
  sed tincidunt. Aliquam porttitor nulla purus, vel vulputater
  ipsum faucibus sed. Phasellus sodales, lorem vel cursus vehi
  ante purus lacini dui, interdum fringilla massa eros ut duir.
</p>
<p>
  Lorem ipsum dolor sit amet, consectetur adipiscing elitorire
  aenean a dapibus magna, ac interdum nisl. Suspendisse egetil
  fringilla nibh, eu commodo arcu. Donec lacinia tempor velite
  sed tincidunt. Aliquam porttitor nulla purus, vel vulputater
  ipsum faucibus sed. Phasellus sodales, lorem vel cursus vehi
  ante purus lacini dui, interdum fringilla massa eros ut duir.
</p>

<h2>Secondary heading 2</h2>
<p>
  Lorem ipsum dolor sit amet, consectetur adipiscing elitorire
  aenean a dapibus magna, ac interdum nisl. Suspendisse egetil
  fringilla nibh, eu commodo arcu. Donec lacinia tempor velite
  sed tincidunt. Aliquam porttitor nulla purus, vel vulputater
  ipsum faucibus sed. Phasellus sodales, lorem vel cursus vehi
  ante purus lacini dui, interdum fringilla massa eros ut duir.
</p>
<p>
  Lorem ipsum dolor sit amet, consectetur adipiscing elitorire
  aenean a dapibus magna, ac interdum nisl. Suspendisse egetil
  fringilla nibh, eu commodo arcu. Donec lacinia tempor velite
  sed tincidunt. Aliquam porttitor nulla purus, vel vulputater
  ipsum faucibus sed. Phasellus sodales, lorem vel cursus vehi
  ante purus lacini dui, interdum fringilla massa eros ut duir.
</p>

<h2>Secondary heading 3</h2>
<table border="1">
  <tr>
    <td>cell 1</td>
    <td>cell 2</td>
    <td>cell 3</td>
  </tr>
  <tr>
    <td>cell 4</td>
    <td>cell 5</td>
    <td>cell 6</td>
  </tr>
  <tr>
    <td>cell 7</td>
    <td>cell 8</td>
    <td>cell 9</td>
  </tr>
</table>