Dawn Image Banner button

[re-dress]

In my dawn theme when I add one Button to my home page image banner, the button is in the centre. however when I add two buttons to the home page image banner both the buttons go off to the left hand side of the page, please see in image attached. can someone please help me centre these buttons 

website url: https://re-dressmx.com/

[KetanKumar]

@re-dress 

1. Go to Online Store->Theme->Edit code
2. Asset->/section-image-banner.css ->paste below code at the bottom of the file.

.banner__box>*+.banner__buttons--multiple {margin: 2rem auto 0px ;}

After code result