You might already notice that every time you focus on the input box, there's a incompatible border which wrap the input box. Actually, it's not a border, it's an outline. Its color is chosen by browser by default. You can remove it by modifying the CSS file in this way.
[developer@test css]# vi web.css
In the above code, #name-input-box is an element id and :focus is a selector belonging to said element id, which can let you style the element whenever focused.