ReactDOM.createPortal modal is mounted on DOM but nothing is displayed on the screen - reactjs

Question

this is a typescript-next.js project. I have this Modal component:
interface ModalProps {
onCancelModal: () => void;
onAcceptModal: () => void;
acceptEnabled: boolean;
isLoading?: boolean;
title: string;
}
const Modal: React.FC<ModalProps> = (props) => {
let containerRef = useRef<HTMLDivElement | null>(null);
console.log("container", containerRef);
useEffect(() => {
const rootContainer = document.createElement("div");
const parentElem = document.querySelector("#__next");
parentElem?.insertAdjacentElement("afterend", rootContainer);
if (!containerRef.current) {
containerRef.current = rootContainer;
}
return () => rootContainer.remove();
}, []);
return containerRef.current
? ReactDOM.createPortal(
<div className="modal">
<header className="modal__header">
<h1>{props.title}</h1>
</header>
<div className="modal__content">{props.children}</div>
<div className="modal__actions">
<Button design="danger" mode="flat" onClick={props.onCancelModal}>
Cancel
</Button>
<Button
mode="raised"
onClick={props.onAcceptModal}
disabled={!props.acceptEnabled}
loading={props.isLoading}
>
Accept
</Button>
</div>
</div>,
containerRef.current
)
: null;
};
export default Modal;
I pass a custom error to ErrorHandler component:
const ErrorHandler: React.FC<ErrorHandlerProps> = (props) => (
<Fragment>
{props.error && <Backdrop onClick={props.onHandle} />}
{props.error && (
<Modal
title="An Error Occurred"
onCancelModal={props.onHandle}
onAcceptModal={props.onHandle}
acceptEnabled
>
<p>{props.error}</p>
</Modal>
)}
</Fragment>
);
However, Modal component is successfully mounted on the DOM but nothing displays on the screen.
EDIT
I have backdrop and modal components.
// css for backdrop
.backdrop {
width: 100%;
height: 100vh;
background: rgba(0, 0, 0, 0.75);
z-index: 100;
position: fixed;
left: 0;
top: 0;
transition: opacity 0.3s ease-out;
opacity: 1;
}
// css for Modal
.modal {
position: fixed;
width: 90%;
left: 5%;
top: 20vh;
background: white;
border-radius: 5px;
z-index: 200;// I changed this to 999999 but didnot solve the issue
box-shadow: 0 2px 8px rgba(0, 0, 0, 0.26);
}
.modal__header {
border-bottom: 2px solid #3b0062;
}
.modal__header h1 {
font-size: 1.5rem;
color: #3b0062;
margin: 1rem;
}
.modal__content {
padding: 1rem;
}
.modal__actions {
padding: 1rem;
text-align: right;
}
.modal__actions button {
margin: 0 0.5rem;
}
#media (min-width: 768px) {
.modal {
width: 40rem;
left: calc((100% - 40rem) / 2);
}
}

Answer 1

I found the answer after i refresh my memory. I realized that there is another .modal className on elements-styles tab. It points me to the /node_modules/bootstrap/scss/_modal.scss file which also has modal className and it was overriding my custom className.
.modal {
position: fixed;
top: 0;
left: 0;
z-index: $zindex-modal;
display: none;
width: 100%;
height: 100%;
overflow: hidden;
// Prevent Chrome on Windows from adding a focus outline. For details, see
// https://github.com/twbs/bootstrap/pull/10951.
outline: 0;
// We deliberately don't use `-webkit-overflow-scrolling: touch;` due to a
// gnarly iOS Safari bug: https://bugs.webkit.org/show_bug.cgi?id=158342
// See also https://github.com/twbs/bootstrap/issues/17695
}