语法高亮，滚动条美化，设置页面调整

docs/javascript/Reference/Global_Objects/Array/pop.html

@@ -4,7 +4,7 @@
 <div><iframe class="interactive interactive-js" frameborder="0" height="250" src="https://interactive-examples.mdn.mozilla.net/pages/js/array-pop.html" width="100%"></iframe></div>
 <p class="hidden">The source for this interactive example is stored in a GitHub repository. If you'd like to contribute to the interactive examples project, please clone <a class="external" href="https://github.com/mdn/interactive-examples" rel="noopener">https://github.com/mdn/interactive-examples</a> and send us a pull request.</p>
 <h2 id="Syntax" name="Syntax">语法</h2>
-<pre class="syntaxbox"><code><em>arr</em>.pop()</code></pre>
+<pre><code class="language-javascript"><code><em>arr</em>.pop()</code></code></pre>
 <h3 id="返回值">返回值</h3>
 <p>从数组中删除的元素(当数组为空时返回<a href="Reference/Global_Objects/undefined" title="undefined是全局对象的一个属性。也就是说，它是全局作用域的一个变量。undefined的最初值就是原始数据类型undefined。"><code>undefined</code></a>)。</p>
 <h2 id="Description" name="Description">描述</h2>
@@ -14,7 +14,7 @@
 <h2 id="Example" name="Example">示例</h2>
 <h3 id="Example:_Removing_the_last_element_of_an_array" name="Example:_Removing_the_last_element_of_an_array">例子: 删除掉数组的最后一个元素</h3>
 <p>下面的代码首先创建了一个拥有四个元素的数组 myFish，然后删除掉它的最后一个元素。</p>
-<pre class="brush:js">let myFish = ["angel", "clown", "mandarin", "surgeon"];
+<pre><code class="language-js">let myFish = ["angel", "clown", "mandarin", "surgeon"];
 
 let popped = myFish.pop();
 
@@ -23,7 +23,7 @@ console.log(myFish);
 
 console.log(popped); 
 // surgeon
-</pre>
+</code></pre>
 <h2 id="规范" style="margin-bottom: 20px; line-height: 30px;">规范</h2>
 <table>
 <tbody>