React Application: How To Create A Black Overlay For A Picture? - css

Question

I'm trying to create a black overlay for a picture featured in the header of my application, using ReactJS and CSS3. However, no matter what I do, it's not working. I've tried referencing old projects in the past, where I managed to pull it off, as well as explored StackOverflow for answers. But, nothing's worked.
Could somebody please help me understand what I'm doing wrong and how I can solve this? I'd really appreciate it.
Header.js
import React from 'react';
// import { Link } from 'react-router-dom';
import Button from 'react-bootstrap/Button';
import ButtonToolBar from 'react-bootstrap/ButtonToolbar';
import './header.css';
const Header = () => {
return (
<div className="header">
<h1 className="title">Linguist Otaku</h1>
<ButtonToolBar>
<Button href="/quiz" size="lg" id="quiz-btn">
Quiz Now
</Button>
</ButtonToolBar>
</div>
)
}
export default Header;
Header.css
:root{
--mainOpacity: rgb(0, 0, 0, .55);
}
.header {
background-image: url("../../images/italy.png");
opacity: var(--mainOpacity);
height: 30em !important;
}
h1 {
font-family: "Fjalla One";
text-align: center !important;
padding-top: 2em !important;
color: white !important;
font-size: 4em !important;
}
.btn-toolbar {
display: flex !important;
justify-content: center !important;
}
#quiz-btn {
font-family: "Roboto";
color: white !important;
margin-top: 3em !important;
background-color: transparent !important;
border: solid .05em white !important;
border-radius: 0em !important;
}
#quiz-btn:hover {
transition: all 0.5s ease-in-out;
background-color: var(--mainOpacity) !important;
}

Answer 1

To create an overlay, you should wrap the content in another div. Then with CSS, position it right in-front of the header/background like so: https://codesandbox.io/s/mystifying-ramanujan-sq491
Header.js
const Header = () => {
return (
<div className="header">
<div className="dark-overlay">
<h1 className="title">Linguist Otaku</h1>
<ButtonToolBar>
<Button href="/quiz" size="lg" id="quiz-btn">
Quiz Now
</Button>
</ButtonToolBar>
</div>
</div>
);
};
CSS
.dark-overlay {
background-color: rgba(0, 0, 0, 0.35);
position: absolute;
top: 0;
left: 0;
width: 100%;
height: 100%;
}

Answer 2

You can give a background image and black overlay together in the css to the "header" or your parent like this:
background-image: linear-gradient( rgba(0, 0, 0, 0.7), rgba(0, 0, 0, 0.7) ),url("../../images/italy.png");