Removing white space between sidebar and main container

Hello, I managed to change the sidebar color to green by this code :
@media only screen and (min-width: 768px) {
.container_wrap.sidebar_right{
background:-webkit-gradient(linear,right top,left top,color-stop(#8dbf42,0.295),color-stop(white,0));
background:-webkit-linear-gradient(right, #8dbf42 29.5%, white 0%);
background: -moz-linear-gradient(right, #8dbf42 29.5%, white 0%);
background: -o-linear-gradient(right, #8dbf42 29.5%, white 0%);
background: linear-gradient(right, #8dbf42 29.5%, white 0%);
}
}
Altough i dont want all the way down green, just the widgets area to be green would be better for me.
My main problem is space between the sidebar and main content is white and I cant make this area’s background to grey.

Hello,
Thank you for your response.
All the posts have sidebar like this page: https://www.sagliklivefit.com/limonlu-su-icmenin-sagliga-yararlari/

Best Regards
Cihan