If you want a real focus state to a div element, you can add a tabindex attribute to it. .row { display:inline-block; border:1px solid grey; ... ... <看更多>

To me at least dropdown selects are more similar to <button> than to other <input> elements. Also, I don't think I'm concerned about not showing ... ... <看更多>

So, if you use chrome inspect, and force state of focus on the div, it will change color. enter image description here. ... <看更多>

The :focus pseudo-class applies while an element has the focus, ... that do not typically accept input, such as div and body elements, receive focus when ... ... <看更多>

Learn about the CSS Focus Within property to create styles on a parent element from a child elements focused ... ... <看更多>