Change bg color to gradient

Hi,
I would like to change the background color to a gradient of two colors.
I was able to do that for the menu and left top of the page by changing the settings in the custom.css.
However below the menu there is still a one colored background I am not able to change.
Could you help to find the correct settings?
Thank you for your help!

Hi there,
please use this container and add this code to your css/custom.css

body, .uk-container, #jp-right {
background: #777777; /* Old browsers */
background: -moz-linear-gradient(left, #777777 0%, #000333 100%); /* FF3.6-15 */
background: -webkit-linear-gradient(left, #777777 0%,#000333 100%); /* Chrome10-25,Safari5.1-6 */
background: linear-gradient(to right, #777777 0%,#000333 100%); /* W3C, IE10+, FF16+, Chrome26+, Opera12+, Safari7+ */

}

Hello,
thank you for the code.
I changed the container to #bg for the left hand side and it works fine