* {
	margin: 0;
	padding: 0;
	box-sizing: border-box;
}

body {
	font-family: "PT Sans", sans-serif;
	font-weight: 400;
	font-style: normal;
	line-height: 48px;
}

.container {
	max-width: 1200px;
	margin: 0 auto;
}

.header {
	position: fixed;
	top: 0;
	left: 0;
	width: 100vw;
	z-index: 2;
	padding: 13px 0px;
	background: #fff;
}

.header .container {
	display: flex;
	justify-content: space-between;
}

.main-layout {
	display: flex;
	flex-direction: row;
}

.nav-lang {
	font-family: "Tourney", sans-serif;
	font-weight: 600;
	font-size: 22px;
	margin-right: 50px;
}

.nav-item {
	font-family: "Staatliches", sans-serif;
	font-weight: 400;
	font-size: 22px;
	text-transform: uppercase;
	text-decoration: none;
	color: #000;
}

.bg-image {
	position: fixed;
	top: 150px;
	right: 0;
	z-index: -1;
}

.side {
	position: sticky;
	top: 66px;
	align-self: flex-start;
	width: 320px;
	padding: 0;
	background: transparent;
}

.side-nav {
	display: flex;
	flex-direction: column;
}

.side-link {
	position: relative;
	margin: 70px 0 40px 20px;
	font-family: "Francois One", sans-serif;
	font-size: 26px;
	text-transform: uppercase;
	color: #000;
	text-decoration: none;
}

.side-link::after {
	content: '';
	position: absolute;
	left: 0;
	bottom: 0;
	width: 80%;
	height: 2px;
	background: #e0e0e0;
}

.main-content {
	flex: 1 1 0;
	max-width: calc(100% - 320px - 30px);
	margin-left: 30px;
	padding-top: 170px;
}

.section {
	margin-bottom: 70px;
	scroll-margin-top: 140px;
}

.section-header {
	padding-bottom: 40px;
}

.section-title {
	display: inline-block;
	position: relative;
	font-family: "Francois One", sans-serif;
	font-weight: 400;
	font-size: 36px;
	text-transform: uppercase;
}

.chapter-number {
	position: absolute;
	top: -8px;
	right: -120px;
	font-family: "Farro", sans-serif;
	font-weight: 300;
	font-size: 18px;
	font-style: normal;
}

.section-title::before {
	content: '';
	position: absolute;
	top: -20px;
	left: 0;
	background: #000;
	width: 100%;
	height: 8px;
}

.section-content {
	font-size: 28px;
	line-height: 1.7;
}

.text-concept,
.concept-item p {
	margin: 40px 0px;
}

.concept-item {
	margin: 16px 0;
}

.bold {
	font-family: "PT Sans", sans-serif;
	font-weight: 700;
}

.italic {
	font-style: italic;
}

.link {
	color: #000;
	text-decoration: underline;
	transition: opacity 0.2s ease;
}

.inline-code {
	background: rgb(198, 198, 198);
}

.title__1 {
	position: relative;
	font-weight: 700;
	font-size: 36px;
	letter-spacing: 1.5px;
	padding-left: 120px;
	margin: 70px 0 40px 0;

}

.title__1::before {
	content: '';
	position: absolute;
	top: 50%;
	left: 0;
	width: 100px;
	height: 8px;
	background-color: #000;
	transform: translateY(-50%);
}

.cards {
	display: flex;
	flex-wrap: wrap;
	gap: 30px;
	border-top: 1px solid #bfbfbf;
	border-bottom: 1px solid #bfbfbf;
	padding: 20px 15px;
}

.card {
	width: 270px;
	height: 180px;
	border-radius: 8px;
	overflow: hidden;
	position: relative;
	transform-style: preserve-3d;
	transition: transform 0.65s linear;
}

.card:hover .card-inner {
	transform: rotateY(180deg);
}

.card-inner {
	position: relative;
	width: 100%;
	height: 100%;
	transform-style: preserve-3d;
	transition: transform 0.65s linear;
}

.card-descr {
	display: flex;
	justify-content: center;
	align-items: center;
	position: absolute;
	width: 100%;
	height: 100%;
}

.card-front {
	background: #e6e6e6;
}

.card-back {
	transform: rotateY(180deg);
	background: #000;
	backface-visibility: hidden;
}