JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
<head>
	<title>Project</title>
<meta http-equiv="Content-type" content="text/html;charset=UTF-8"/>
<link rel="stylesheet" href="css/styles.css" />
<meta name="viewport" content="width=device-width, initial-scale=1">
</head>
<body>
	<div class="wrapper">
		<header>
			<div class="upper-line-row">
				<div class="logo">
					<div class="logo-wrapper"><a href="#"><span>dart</span><br>service manager</a></div>
					</div>
					<div class="menu-list">
						<a href="">Home</a>
						<a href="">Service</a>
						<a href="">Extension</a>
						<a href="">Pricing</a>
						<a href="">Help</a>
					</div>
				<div class="header__ulr__register">
					<a href="">sign up</a>
				</div>
			</div>
			<div class="header__main-line">
				<div class="header__ml__intro-row">
					<h1>lorem Ipsum
					Dolor sit amet</h1>
					<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamc</p>
					<div class="hml__intro-buttons" class="text">
						<a href="" class="hmli-b__btn-purchase button">buy now</a>
						<a href="" class="hmli__btn-demo button">try for free</a>
					</div>
				</div>
				<div class="hml__video-container" class="video-container"><div class="video-button"></div>
					<video class="hml__video" src=""></video></div>
			</div>
		</header>
		<section class="easyNuseful">
			<div class="easyNuseful__title-row">
				<h1 class="title">Easy & Useful</h1>
				<h2>Project Management Tool</h2>
				<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud</p></div>
			</p>
			<div class="easyNuseful__icons-row">
				<div class="icon_calendar icon">
					<div class="icon_calendar__image"></div>
					<h3>Title Goes Here</h3>
					<p>Lorem ipsum dolor sit amet, consectetur<br>adipisicing elit, sed do eiusmod tempor...

CSS

// проблема со строки 545

@import "nullstyle.scss";
@import url('https://fonts.googleapis.com/css2?family=Raleway:ital,wght@0,100;0,200;0,300;0,400;0,500;0,600;0,700;0,800;0,900;1,100;1,200;1,300;1,400;1,500;1,600;1,700;1,800;1,900&display=swap');

body {
	font-family: 'Raleway', sans-serif;
	& a {
		color: #fff;
	}
}
p {
	font-size: 15px;
}
.wrapper {
	max-width: 1600px;
	margin: 0px auto;
	cursor: default;
}
.title {
	font-size: 45px;
	font-weight: 600;
	text-align: center;
	color: #061e37;
}
.video-container {
	position: relative;
}
.button {
	display: flex;
	align-items: center;
	justify-content: center;
	user-select: none;
}
.button_getStarted {
	margin: 78px 0 0 15px;
	border-radius: 5px;
	box-shadow: 0px 5px 5px 0 rgba(0, 0, 0, 0.15);
	width: 150px;
	height: 55px;
	font-size: 15px;
	text-align: center;
	padding: 2px 0 0 2px;
	font-weight: bold;
	text-transform: uppercase;
	transition: color 300ms ease 0s;
	&:hover {
		color: #061e37;
	}
}

header {
	color: #fff;
	text-decoration-color: #fff;
	min-width: 100%;
	height: 750px;
	background: url(../img/BG.png) no-repeat center;
	padding: 50px 80px 0 80px;
}
.upper-line-row {
	width: 100%;
	height: 30px;
	display: flex;
	flex-direction: row;
	justify-content: space-between;
	user-select: none;
}
.logo {
	flex: 1 1 33.333%;
	font-size: 15px;
	font-weight: 800;
	line-height: 1;
	text-transform: uppercase;
	& .logo-wrapper span {
		opacity: 0.8;
		font-weight: 600;
	}
	&::before {
		content: url(../img/dartLogo.png);
		position: absolute;
		margin-top: -2px;
	}
}
.logo-wrapper {
	padding-left: 42px;
}
.menu-list {
	flex: 0 1 441px;
	display: flex;
	flex-direction: row;
	align-items: center;
	justify-content: space-between;
	padding-top: 0px;
	font-size: 15px;
	font-weight: 600;
	line-height: 1.67;
	color: #ffffff;
	& a {
		transition: color 400ms ease;
		&:hover {
			color: #061e37;
		}
	}
}
.menu-list_footer {
	flex: 0 1 441px;
	display: flex;
	flex-direction: row;
	align-items: center;
	justify-content:...

JavaScript

$(document).ready(function() {
	$('.testimonals__comments').slick()
});