Exclude sidebar widgets from h2 styling

Hi all,

I put a style to all my h2 elements but want to exclude my right sidebar widgets from having the same style.
I tried using :not() but I’m not sure I am using it correctly.
Below is the css I used to style h2.

h2 {
margin-top: 10px;
background-color: rgb(0, 169, 224);
padding-top: 10px;
padding-bottom: 10px;
margin-left: 0px;
padding-left: 10px;
line-height: 35px;
}