function addInertStyle(node) {
    if (node.querySelector('style#inert-style')) {
      return;
    }
    var style = document.createElement('style');
    style.setAttribute('id', 'inert-style');
    style.textContent = '\n' + '[inert] {\n' + '  pointer-events: none;\n' + '  cursor: default;\n' + '}\n' + '\n' + '[inert], [inert] * {\n' + '  user-select: none;\n' + '  -webkit-user-select: none;\n' + '  -moz-user-select: none;\n' + '  -ms-user-select: none;\n' + '}\n';
    node.appendChild(style);
  }
Adds a style element to the node containing the inert specific styles
@param {!Node} node