如何更改这个ui-select元素的样式表?(角)

I wrote a little program in angular using an ui-select element. The problem is that the search bar is really too long and I didn't find how to reduce it. Usually, we have some "width" properties that you can change for that but the css code is too complicated and I didn't find how to manage that. What I want to do is to save three bars at the same line. I wrote a little program in angular using an ui