Cause: Because you are not satisfied with the default style, there are two default effects: dark and light. When I need to customize it, I want to set the color of the border of the background color. The two can be set with popper-class, but you will find that the pointed part of the arrow is not affected.
Screenshot of the problem:
As you can see, what I set for the border is the light gray in the picture, but it will not affect the color of the arrow.
Solution:
The modified effect:
Just set it as shown in the picture. Note that the red boxes must be consistent.
⚠️Note:
1. I am right here. The specific direction depends on the direction your el-tooltip is facing. You can refer to the element-ui document for this.
2. The styles involved in this article needto be modified in APP.vue to take effect, and will not take effect inside the component