W3Schools Tryit Editor

<!doctype html>
<html>

<body>
<p>The CSS selector a[target] makes sure that all links with a target attribute gets a yellow background:</p>
<div id="myDIV">
 Three links inside div:
 <a href="https://www.w3schools.com">w3schools.com</a>
 <a href="/index.cgi/contrast/http://www.disney.com">disney.com</a>
 <a href="/index.cgi/contrast/http://www.wikipedia.org">wikipedia.org</a>
</div>
<p>Click the button to add a red border to the first link that has a target attribute inside the div element.</p>
<button>Try it</button>
</div><div class="naked_ctrl">
<form action="/index.cgi/contrast" method="get" name="gate">
<p><a href="http://altstyle.alfasado.net">AltStyle</a> によって変換されたページ <a href="http://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_element_queryselector_attribute">(->オリジナル)</a>
/ <label>アドレス: <input type="text" name="naked_post_url" value="http://www.w3schools.com/jsref/tryit.asp?filename=tryjsref_element_queryselector_attribute" size="22" /></label> <label>モード: <select name="naked_post_mode">
<option value="default">デフォルト</option>
<option value="speech">音声ブラウザ</option>
<option value="ruby">ルビ付き</option>
<option value="contrast" selected="selected">配色反転</option>
<option value="larger-text">文字拡大</option>
<option value="mobile">モバイル</option>
</select>
<input type="submit" value="表示" />
</p>
</form>
</div>		
</body>
</html>