Image border right of sidebar

Hi, Great theme! thank you
i have one issue, in the sidebar i have an image but between Sidebar and content i try to become a gold border (with an image)

My css code i try is:
.sidebar {
background-image: url(‘https://xxxxx.xx/wp-content/uploads/2017/10/goldborder.png’);
background-position: right ;
background-repeat: repeat-y;
display: block;
}
but this does not work, however this code works well
.sidebar {
border-style: solid;
border-right: thick double #ff0000;
}
have you any idea to fix this, at this moment i make the border in the sidebar image but it disapear in a 1280 x 1024 screen

Thanks