“外轮廓是属于一种动态样式，只有元素获取到焦点或者被激活时呈现”怎么理解？

Answer 1

How do you understand "The outer outline is a dynamic style, which is only displayed when the element gets focus or is activated"? -PHP Chinese website Q&A - "The outer outline is a dynamic style, which is only displayed when the element gets focus or is activated." What do you understand? -PHP Chinese website Q&A

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Answer 2

就好比你定义一个输入框，输入框在鼠标点击获取焦点之后，才会有一个外轮廓， 鼠标点击别处输入框失去焦点，外轮廓就没有了，你可以定义外轮廓的颜色等参数。 外轮廓只有在获取焦点的时候才会出现，所以是动态生成的的咯。