style.css

/* Import the fonts link from fontawesome  */
@import url('https://fonts.googleapis.com/css2?family=Muli:ital,wght@0,400;1,700&display=swap');

* {
	box-sizing: border-box; /*border-box: If we add any padding or any border onto any element it doesn't actually affect the width of it */
}

body {
	font-family: 'Muli', sans-serif;
	display: flex; /*The element behaves like a block element(generating line breaks both before and after the element when in the normal flow) and lays out its content according to the flexbox model. To center everything */
	align-items: center;
	justify-content: center;
	height: 100vh; /* set w.r.t. viewport */
	overflow: hidden; /* To prevent scrollbars to be shown by default */
	margin: 0;
}

.container {
	display: flex;
	width: 90vw;
}

.panel {
	background-size: cover;
	background-position: center;
	background-repeat: no-repeat;
	height: 80vh;
	border-radius: 50px;

	color: rgb(0, 0, 0);
	background-color: #232323;
	text-shadow: 1px 2px 2px #e5e8eb;
	cursor: pointer; /* On hovering a cursor will appear */
	flex: 0.5;
	margin: 10px;
	position: relative; /* position property used to manipulate the location of an element. relative: the top/bottom/left/right/z-index will work. */
	transition: flex 0.7s ease-in;
}

.panel h3 {
	font-size: 24px;
	position: absolute;
	bottom: 20px;
	left: 20px;
	margin: 0;
	opacity: 0;
}

.panel.active {
	flex: 5;
}

.panel.active h3 {
	opacity: 1;
	transition: opacity 0.3s ease-in 0.6s;
}

@media (max-width: 480px) {
	.container {
		width: 100vw;
	}

	.panel:nth-of-type(4),
	.panel:nth-of-type(5) {
		display: none;
	}
}