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

body {
	font-family: 'Segoe UI', 'Microsoft YaHei', Arial, sans-serif;
	background: linear-gradient(135deg, #232946 0%, #1a1a2e 100%);
	color: #eaf0fa;
	margin: 0;
	padding: 48px 20px 48px 20px;
	box-sizing: border-box;
	min-height: 100vh;
	transition: background 0.4s;
	::selection {
		background: #7a7e92;
	}
	b,
	strong {
		color: #ffffff;
	}
}

.main-card {
	max-width: 860px;
	margin: 0 auto 48px auto;
	background: rgba(34, 39, 70, 0.98);
	border-radius: 26px;
	box-shadow: 0 8px 36px 0 rgba(40, 60, 120, 0.22), 0 2px 8px 0 rgba(40, 60, 120, 0.13), 0 0 0 1.5px #2d325a;
	padding: 0 0 36px 0;
	backdrop-filter: blur(2px);
}

.main-header {
	background: linear-gradient(90deg, #4e54c8 0%, #8f94fb 100%);
	color: #fff;
	font-size: 1.22em;
	font-weight: 700;
	letter-spacing: 1.2px;
	text-align: center;
	padding: 32px 36px 22px 36px;
	border-radius: 26px 26px 0 0;
	box-shadow: 0 2px 12px 0 rgba(60, 90, 130, 0.13);
	margin-bottom: 0;
	position: relative;
}

.lang-toggle {
	position: absolute;
	top: 32px;
	right: 36px;
	width: 40px;
	height: 40px;
	background: rgba(255, 255, 255, 0.15);
	border-radius: 50%;
	display: flex;
	align-items: center;
	justify-content: center;
	cursor: pointer;
	transition: all 0.3s ease;
	border: 1.5px solid rgba(255, 255, 255, 0.25);
	backdrop-filter: blur(4px);
}

.lang-toggle:hover {
	background: rgba(255, 255, 255, 0.25);
	transform: scale(1.1);
	box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.lang-toggle svg {
	width: 22px;
	height: 22px;
	fill: #fff;
}
.main-title {
	font-size: 2.1em;
	font-weight: 900;
	letter-spacing: 2px;
	margin-bottom: 0.18em;
	text-shadow: 0 4px 24px #23294655;
}
.main-subtitle {
	font-size: 1.05em;
	font-weight: 400;
	letter-spacing: 0.5px;
	opacity: 0.92;
	margin-top: 0.2em;
}

.fold {
	background: linear-gradient(120deg, rgba(34, 39, 70, 0.98) 70%, rgba(78, 84, 200, 0.13) 100%);
	border-radius: 16px;
	box-shadow: 0 2px 16px 0 rgba(60, 90, 130, 0.13);
	margin: 32px 36px 0 36px;
	overflow: hidden;
	transition: box-shadow 0.25s, background 0.25s;
	border: 1.2px solid #2d325a;
}
.fold:last-child {
	margin-bottom: 0;
}
.fold:hover {
	box-shadow: 0 8px 32px 0 rgba(78, 84, 200, 0.22), 0 2px 8px 0 rgba(60, 90, 130, 0.13);
	background: linear-gradient(120deg, #232946 60%, #4e54c8 100%);
}

.fold-title {
	cursor: pointer;
	background: linear-gradient(90deg, #4e54c8 0%, #8f94fb 100%);
	color: #fff;
	padding: 20px 32px;
	font-size: 1.18em;
	font-weight: 700;
	letter-spacing: 1.1px;
	border: none;
	transition: background 0.22s, color 0.22s;
	user-select: none;
	position: relative;
	border-bottom: 1px solid #2d325a;
}
.fold-title::after {
	content: '▼';
	position: absolute;
	right: 36px;
	top: 50%;
	transform: translateY(-50%) rotate(-90deg);
	transition: transform 0.35s cubic-bezier(0.4, 2, 0.6, 1), color 0.2s;
	font-size: 1.1em;
	opacity: 0.7;
	color: #b3baff;
}
.fold-title.open::after {
	transform: translateY(-50%) rotate(0deg);
	color: #fff;
}

.fold-content {
	padding: 26px 38px 22px 38px;
	background: linear-gradient(90deg, #232946 80%, #2d325a 100%);
	border-left: 5px solid #4e54c8;
	margin: 0;
	font-size: 1.07em;
	line-height: 1.85;
	animation: fadeIn 0.45s;
	color: #eaf0fa;
}

ul {
	margin: 0 0 0 1.7em;
	padding: 0;
}
li {
	margin: 8px 0;
	position: relative;
	padding-left: 1.2em;
	list-style: none;
}
li::before {
	content: '';
	position: absolute;
	left: 0;
	top: 1em;
	transform: translateY(-50%);
	width: 0.65em;
	height: 0.65em;
	border-radius: 50%;
	background: radial-gradient(circle at 60% 40%, #b3baff 60%, #4e54c8 100%);
	box-shadow: 0 0 4px #8f94fb99;
}

ul ul {
	margin-left: 1.5em;
}
ul ul li::before {
	background: radial-gradient(circle at 60% 40%, #8f94fb 60%, #4e54c8 100%);
	width: 0.55em;
	height: 0.55em;
	box-shadow: 0 0 2px #6c70d899;
}
ul ul ul li::before {
	background: radial-gradient(circle at 60% 40%, #4e54c8 60%, #232946 100%);
	width: 0.45em;
	height: 0.45em;
	box-shadow: 0 0 1px #23294699;
}

h3,
h4,
h5 {
	margin-top: 1.3em;
	margin-bottom: 0.6em;
	font-weight: 700;
}
h3 {
	color: #b3baff;
	font-size: 1.28em;
	border-left: 4px solid #4e54c8;
	padding-left: 12px;
	background: none;
	text-shadow: 0 2px 8px #23294655;
}
h4 {
	color: #8f94fb;
	font-size: 1.13em;
	border-left: 3px solid #6c70d8;
	padding-left: 10px;
	background: none;
}
h5 {
	color: #4e54c8;
	font-size: 1.05em;
	border-left: 3px solid #8f94fb;
	padding-left: 9px;
	background: none;
}

blockquote {
	color: #b3baff;
	border-left: 5px solid #4e54c8;
	background: linear-gradient(90deg, #232946 80%, #2d325a 100%);
	margin: 18px 0;
	padding: 12px 22px;
	border-radius: 8px;
	font-style: italic;
	box-shadow: 0 2px 8px 0 rgba(78, 84, 200, 0.08);
}

code {
	background: #181b2a;
	padding: 3px 8px;
	border-radius: 5px;
	font-family: 'JetBrains Mono', 'Consolas', monospace;
	color: #8f94fb;
	font-size: 1em;
	border: 1px solid #2d325a;
}

@keyframes fadeIn {
	from {
		opacity: 0;
		transform: translateY(18px);
	}
	to {
		opacity: 1;
		transform: none;
	}
}

::-webkit-scrollbar {
	width: 8px;
	background: #232946;
}
::-webkit-scrollbar-thumb {
	background: #4e54c8;
	border-radius: 4px;
}