> For the complete documentation index, see [llms.txt](https://ayugioh2003.gitbook.io/free-code-camp-practice/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://ayugioh2003.gitbook.io/free-code-camp-practice/front-end-development-certification/html5-and-css/html5-and-css-21-30.md).

# HTML5 and CSS: 21-30

21 Link to External Pages with Anchor Elements

* Anchor Element `<a>` 錨點
* `<a href="http://freecatphotoapp.com">cat photos</a>`

```markup
<link href="https://fonts.googleapis.com/css?family=Lobster" rel="stylesheet" type="text/css">
<style>
  .red-text {
    color: red;
  }

  h2 {
    font-family: Lobster, Monospace;
  }

  p {
    font-size: 16px;
    font-family: Monospace;
  }

  .thick-green-border {
    border-color: green;
    border-width: 10px;
    border-style: solid;
    border-radius: 50%;
  }

  .smaller-image {
    width: 100px;
  }
</style>

<h2 class="red-text">CatPhotoApp</h2>


<img class="smaller-image thick-green-border" src="https://bit.ly/fcc-relaxing-cat" alt="A cute orange cat lying on its back. ">

<a href="http://freecatphotoapp.com">cat photos</a>

<p class="red-text">Kitty ipsum dolor sit amet, shed everywhere shed everywhere stretching attack your ankles chase the red dot, hairball run catnip eat the grass sniff.</p>
<p class="red-text">Purr jump eat the grass rip the couch scratched sunbathe, shed everywhere rip the couch sleep in the sink fluffy fur catnip scratched.</p>
```

22 - Nest an Anchor Element within a Paragraph

* 例子

```markup
<p>View more cat photos
<a href="http://www.freecatphotoapp.com">cat photos</a>
</p>
```

* 作業

```markup
<link href="https://fonts.googleapis.com/css?family=Lobster" rel="stylesheet" type="text/css">
<style>
  .red-text {
    color: red;
  }

  h2 {
    font-family: Lobster, Monospace;
  }

  p {
    font-size: 16px;
    font-family: Monospace;
  }

  .thick-green-border {
    border-color: green;
    border-width: 10px;
    border-style: solid;
    border-radius: 50%;
  }

  .smaller-image {
    width: 100px;
  }
</style>

<h2 class="red-text">CatPhotoApp</h2>

<p>View more cat photos
<a href="http://www.freecatphotoapp.com">cat photos</a>
</p>

<img class="smaller-image thick-green-border" src="https://bit.ly/fcc-relaxing-cat" alt="A cute orange cat lying on its back. ">

<p class="red-text">Kitty ipsum dolor sit amet, shed everywhere shed everywhere stretching attack your ankles chase the red dot, hairball run catnip eat the grass sniff.</p>
<p class="red-text">Purr jump eat the grass rip the couch scratched sunbathe, shed everywhere rip the couch sleep in the sink fluffy fur catnip scratched.</p>
```

23 - Make Dead Links using the Hash Symbol

* 不想那麼早放上連結，就用 `#` 井字號代替

```markup
<p>Click here for <a href="#">cat photos</a>.</p>
```

24 - Turn an Image into a Link

```markup
<a href="#">
<img class="smaller-image thick-green-border" src="https://bit.ly/fcc-relaxing-cat" alt="A cute orange cat lying on its back. ">
</a>
```

25 - Create a Bulleted Unordered List

```markup
<ul>
  <li>魚</li>
  <li>老鼠</li>
  <li>紙箱子</li>
</ul>
```

26 - Create an Ordered List

```markup
<p>Top 3 things cats hate:</p>
<ol>
  <li>水</li>
  <li>蛇</li>
  <li>小黃瓜</li>
</ol>
```

27 - Create a Text Field

* 原來建立輸入方塊這麼簡單 @@
* `<input type="text">`

28 - Add Placeholder Text to a Text Field

* 能預先顯示佔位符，當作預先定義文本
* `<input type="text" placeholder=" cat photo URL">`

29 - Create a Form Element

* 能夠傳送表單，`action` 定義傳送的方式
* 像範例，回車後，會傳送一個網址

```markup
<form action="/submit-cat-photo">
  <input type="text" placeholder="cat photo URL" >
</form>
```

30 - Add a Submit Button to a Form

* 透過 button 的 type="submit"，點擊 button 後，可以將資料透過 form 的 acton="path"，傳送到某個位址上

```markup
<form action="/submit-cat-photo">
  <input type="text" placeholder="cat photo URL">
  <button type="submit">Submit</button>
</form>
```

&#x20; Submit