anchor.diff:    ### 元数据中的样式表URL
     
     We can load styles from external CSS files by adding a `styleUrls` attribute
  -  into a component's `@Component` or `@View` #{_decorator}:
  -  
  -  我们还可以通过给组件的`@Component`或`@View`#{_decoratorCn}中添加一个`styleUrls`属性来从外部CSS文件中加载样式：
  +  into a component's `@Component` #{_decorator}:
  +  
  +  我们还可以通过给组件的`@Component`#{_decoratorCn}中添加一个`styleUrls`属性来从外部CSS文件中加载样式：
     
   +makeExample('component-styles/ts/app/hero-details.component.ts', 'styleurls')
   
  
positive.code:   1. We can co-locate the CSS code of each component with the TypeScript and HTML code of the component,
       which leads to a neat and tidy project structure.
       
    1. 我们可以让每个组件的CSS代码和它的TypeScript代码、HTML代码放在一起，这将产生清爽整洁的项目结构。
       
    1. We can change or remove component CSS code in the future without trawling through the
       whole application to see where else it may have been used. We just look at the component we're in.
  
negative.code:   
    它的实现方式之一，是在组件的元数据中设置`styles`属性。
    `styles`属性可以接受一个包含CSS代码的字符串数组。
    通常我们只给它一个字符串就行了，如同下例：
    
  +makeExample('component-styles/ts/app/hero-app.component.ts')(format='.')
  
  :marked
    Component styles differ from traditional, global styles in a couple of ways.
    
    组件样式在很多方面都不同于传统的全局性样式。
    
    Firstly, the selectors we put into a component's styles *only apply within the template
    of that component*. The `h1` selector in the example above only applies to the `<h1>` tag
  