ct-ckeditor/plugins/dialog/styles/dialog.css

ct-ckeditor

.cke_dialog_open {
	overflow: hidden;
}

.cke_dialog_container {
	position: fixed;
	overflow-y: auto;
	overflow-x: auto;
	width: 100%;
	height: 100%;
	top: 0;
	left: 0;
	z-index: 10010;
}

.cke_dialog_body {
	position: relative;
}