button remove black frame

If you want to remove the black frame of the button, you can use the following two properties:

border: none;outline: none;

But when I click the button, I will find that the black box appears again. At this time, we can use the developer tools to debug, as shown in the figure:

You can see that since the project introduces bootstrap, when the buttonWhen the focus is obtained, a black frame will appear again:

So the solution is to override this property, the following code:

.button:focus {outline: none;}