*the code seems to be working fine, or at least the window is showing the gradient, but I keep getting informed that I should “add a background property”
Please provide the link of the lesson you are working on so we can see the issue better.
I’ve edited your post for readability. When you enter a code block into a forum post, please precede it with a separate line of three backticks and follow it with a separate line of three backticks to make it easier to read.
You can also use the “preformatted text” tool in the editor (</>) to add backticks around text.
I don’t know what is the task but for now there is already something that should attract your attention into your CSS definition. You use the super propriety background which include then background color. You must know it as you used the linear-gradient() function. Now, look the last property you use in your bb1a class.