Java: Non-Static Type Variable T Cannot be Referenced from a Static Context, for Binary Tree

Question

I'm encountering the error message "non-static type variable T cannot be referenced from a static context". It shows Required type: Node <T> Provided: Node<T>

I'm struggling to understand what I am doing wrong, but as I understand, there's an issue with using the generic type T in static context. I would appreciate any help, thanks.

class BinaryTree<T> {
    private static Node<T> rootNode;

    public static class Node<T> {
        private final T value;
        private Node<T> left;
        private Node<T> right;

        public Node(T value) {
            this.value = value;
            this.left = null;
            this.right = null;
            if (rootNode == null){
                rootNode = this;
            }
        }
    }

    public BinaryTree() {
        rootNode = null;
    }
}

I am trying to implement a Binary Tree. I have a static inner class Node inside a BinaryTree class with a generic type. I want to set a static variable (rootNode) within the inner class based on a condition if it is null.