设置外轮廓outline: none;

    1. <!DOCTYPE html>
    2. <html lang="en">
    3. <head>
    4.   <meta charset="UTF-8">
    5.   <title>Document</title>
    6. </head>
    7. <body>
    8.   <a href="#">百度一下</a>
    9.   <input type="text" value="">
    10. </body>
    11. </html>

    07.消除a、input元素的focus轮廓效果 - 图1

        a,input{
      outline: none;
    }

    07.消除a、input元素的focus轮廓效果 - 图2