Use max-width on modal-dialog for angular 5
.mod-class .modal-dialog {
max-width: 1000px;
}
and use windowClass as others recommended, TS eg:
this.modalService.open(content, { windowClass: 'mod-class' }).result.then(
(result) => {
// this.closeResult = `Closed with: ${result}`;
}, (reason) => {
// this.closeResult = `Dismissed ${this.getDismissReason(reason)}`;
});
Also, I had to put the css code in global styles > styles.css.