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

html {
	scroll-behavior: smooth;
}

body {
	font-family:
		-apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue',
		Arial, sans-serif;
	line-height: 1.6;
	color: #1a1a1a;
	background-color: #ffffff;
	font-size-adjust: 0.5;
}

main {
	min-height: calc(100vh - 80px);
}

/* Header Navigation */
header {
	border-bottom: 1px solid #e5e5e5;
	padding: 1rem 0;
	position: sticky;
	top: 0;
	background-color: #ffffff;
	z-index: 100;
}

nav {
	max-width: 1200px;
	margin: 0 auto;
	padding: 0 2rem;
	display: flex;
	justify-content: space-between;
	align-items: center;
}

.logo {
	font-size: 1.5rem;
	font-weight: 600;
	letter-spacing: -0.5px;
	color: #1a1a1a;
	text-decoration: none;
}

/* Footer */
footer {
	background-color: #f9f9f9;
	border-top: 1px solid #e5e5e5;
	padding: 2rem;
	margin-top: 4rem;
	text-align: center;
}

footer p {
	color: #999;
	font-size: 0.9rem;
}

/* Markdown Document Page */
.markdown-page {
	max-width: 1200px;
	margin: 0 auto;
	padding: 4rem 2rem 3rem;
}

.markdown-container {
	max-width: 1000px;
	margin: 0 auto;
	background-color: #ffffff;
	border: 1px solid #e5e5e5;
	border-radius: 8px;
	padding: 3rem 3.5rem 2.5rem;
	box-shadow: 0 8px 24px rgba(0, 0, 0, 0.04);
	width: 100%;
	content-visibility: auto;
}

.markdown-meta {
	margin-bottom: 1.5rem;
	border-bottom: 1px solid #f0f0f0;
	padding-bottom: 1rem;
}

.markdown-meta h1 {
	font-size: 2rem;
	font-weight: 700;
	margin-bottom: 0.25rem;
}

.markdown-filename {
	font-size: 0.9rem;
	color: #999;
}

/* Directory Page */
.directory-page {
	max-width: 1200px;
	margin: 0 auto;
	padding: 4rem 2rem 3rem;
}

.directory-header {
	margin-bottom: 2rem;
	display: flex;
	justify-content: space-between;
	align-items: center;
	flex-wrap: wrap;
	gap: 1rem;
}

.directory-header-content {
	display: flex;
	flex-direction: column;
	gap: 0.25rem;
}

.directory-header h1 {
	font-size: 2rem;
	font-weight: 700;
	line-height: 1.2;
	margin: 0;
}

/* Sort Controls */
.sort-controls {
	display: flex;
	align-items: center;
	gap: 0.5rem;
	padding: 0.5rem 0.85rem;
	background-color: #ffffff;
	border-radius: 6px;
	border: 1px solid #e5e5e5;
	flex-shrink: 0;
	margin-top: 2.5rem;
}

.sort-label {
	font-size: 0.85rem;
	color: #666;
	font-weight: 500;
}

.sort-btn {
	padding: 0.4rem 0.85rem;
	border: 1px solid #e5e5e5;
	background-color: #ffffff;
	color: #666;
	border-radius: 4px;
	font-size: 0.85rem;
	cursor: pointer;
	transition: all 0.2s;
}

.sort-btn:hover {
	background-color: #f5f5f5;
	border-color: #ccc;
}

.sort-btn.active {
	background-color: #1a1a1a;
	color: #ffffff;
	border-color: #1a1a1a;
}

.breadcrumb {
	font-size: 0.9rem;
	color: #666;
	margin-bottom: 0.75rem;
}

.breadcrumb a {
	color: #0066cc;
	text-decoration: none;
	display: inline-block;
}

.breadcrumb a:hover {
	text-decoration: underline;
}

.breadcrumb .current {
	color: #1a1a1a;
	font-weight: 500;
}

.directory-header h1 {
	font-size: 2rem;
	font-weight: 700;
	line-height: 1.2;
}

.directory-section {
	background-color: #f9f9f9;
	border-radius: 8px;
	padding: 2rem;
	min-height: 300px;
}

.directory-grid {
	display: grid;
	grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
	gap: 1.5rem;
}

/* Markdown container inside directory grid (index.html) */
#directory-grid .markdown-container {
	grid-column: 1 / -1;
	max-width: 100%;
	margin: 0;
}

.directory-item {
	background-color: #ffffff;
	padding: 1.5rem;
	border-radius: 8px;
	border: 1px solid #e5e5e5;
	transition: all 0.3s;
	text-decoration: none;
	color: inherit;
	display: flex;
	flex-direction: column;
	align-items: center;
	text-align: center;
}

.directory-item:hover {
	border-color: #1a1a1a;
	box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
	transform: translateY(-2px);
}

.folder-icon,
.file-icon {
	font-size: 2.5rem;
	margin-bottom: 0.75rem;
	line-height: 1;
	width: 2.5rem;
	height: 2.5rem;
	display: flex;
	align-items: center;
	justify-content: center;
}

.directory-item h3 {
	font-size: 1rem;
	font-weight: 600;
	margin-bottom: 0.5rem;
	color: #1a1a1a;
	line-height: 1.3;
	overflow: hidden;
	text-overflow: ellipsis;
	white-space: nowrap;
	width: 100%;
}

.directory-item .item-desc {
	font-size: 0.85rem;
	color: #666;
	margin-bottom: 0.5rem;
	line-height: 1.4;
	display: -webkit-box;
	-webkit-line-clamp: 2;
	-webkit-box-orient: vertical;
	overflow: hidden;
}

.directory-item .item-date {
	font-size: 0.8rem;
	color: #999;
	margin-bottom: 0.25rem;
}

.directory-item .item-type {
	font-size: 0.75rem;
	color: #666;
	text-transform: uppercase;
	letter-spacing: 0.5px;
}

.directory-item.folder-card h3 {
	color: #0066cc;
	min-height: 1.2em;
}

.directory-empty {
	text-align: center;
	color: #999;
	padding: 3rem;
	grid-column: 1 / -1;
}

/* Skeleton loading state */
.skeleton {
	background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
	background-size: 200% 100%;
	animation: skeleton-loading 1.5s infinite;
	border-radius: 4px;
}

@keyframes skeleton-loading {
	0% {
		background-position: 200% 0;
	}
	100% {
		background-position: -200% 0;
	}
}

.skeleton-card {
	background-color: #ffffff;
	padding: 1.5rem;
	border-radius: 8px;
	border: 1px solid #e5e5e5;
	display: flex;
	flex-direction: column;
	align-items: center;
	text-align: center;
}

.skeleton-icon {
	width: 40px;
	height: 40px;
	margin-bottom: 0.75rem;
}

.skeleton-title {
	width: 80%;
	height: 16px;
	margin-bottom: 0.5rem;
}

.skeleton-desc {
	width: 100%;
	height: 12px;
	margin-bottom: 0.35rem;
}

.skeleton-desc:last-child {
	width: 60%;
}

.markdown-body {
	font-size: 1rem;
	line-height: 1.8;
	color: #1a1a1a;
}

.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6 {
	margin-top: 1.75rem;
	margin-bottom: 0.75rem;
	font-weight: 600;
	line-height: 1.3;
}

.markdown-body h1 {
	font-size: 1.9rem;
}
.markdown-body h2 {
	font-size: 1.6rem;
}
.markdown-body h3 {
	font-size: 1.3rem;
}
.markdown-body h4 {
	font-size: 1.1rem;
}
.markdown-body h5 {
	font-size: 1rem;
}
.markdown-body h6 {
	font-size: 0.9rem;
}

.markdown-body p {
	margin-bottom: 1rem;
	color: #333;
}

.markdown-body a {
	color: #0066cc;
	text-decoration: none;
}

.markdown-body a:hover {
	text-decoration: underline;
}

.markdown-body ul,
.markdown-body ol {
	margin: 0 0 1.25rem 1.5rem;
}

.markdown-body li + li {
	margin-top: 0.35rem;
}

.markdown-body code {
	background-color: #f5f5f5;
	padding: 0.2rem 0.4rem;
	border-radius: 4px;
	font-family:
		SFMono-Regular, Menlo, Monaco, Consolas, 'Liberation Mono', 'Courier New',
		monospace;
	font-size: 0.9em;
}

.markdown-body pre {
	background-color: #0f172a;
	color: #e5e7eb;
	padding: 1rem 1.25rem;
	border-radius: 6px;
	overflow-x: auto;
	margin-bottom: 1.5rem;
	font-family:
		SFMono-Regular, Menlo, Monaco, Consolas, 'Liberation Mono', 'Courier New',
		monospace;
	font-size: 0.9em;
}

.markdown-body pre code {
	background-color: transparent;
	padding: 0;
	color: inherit;
}

.markdown-body blockquote {
	border-left: 3px solid #e5e5e5;
	padding-left: 1rem;
	color: #666;
	margin: 1.25rem 0;
}

.markdown-body table {
	width: 100%;
	border-collapse: collapse;
	margin: 1.5rem 0;
	font-size: 0.95rem;
	display: block;
	overflow-x: auto;
}

.markdown-body th,
.markdown-body td {
	border: 1px solid #e5e5e5;
	padding: 0.5rem 0.75rem;
	text-align: left;
}

.markdown-body th {
	background-color: #f9f9f9;
	font-weight: 600;
}

.markdown-body hr {
	border: 0;
	border-top: 1px solid #e5e5e5;
	margin: 2rem 0;
}

.markdown-body img {
	max-width: 100%;
	height: auto;
	display: block;
	margin: 1.5rem auto;
	border-radius: 6px;
}

/* MathJax Math Styling */
.math-block,
mjx-container[display='true'] {
	display: block;
	margin: 1.5rem 0;
	text-align: center;
	overflow-x: auto;
}

.math-inline,
mjx-container:not([display='true']) {
	display: inline;
	white-space: nowrap;
	margin: 0 0.1em !important;
}

/* Responsive */
@media (max-width: 768px) {
	nav {
		padding: 0 1rem;
	}

	.markdown-page {
		padding: 2rem 1rem;
	}

	.markdown-container {
		padding: 1.5rem;
	}

	.directory-page {
		padding: 2rem 1rem;
	}

	.directory-header {
		flex-direction: column;
		align-items: flex-start;
		gap: 0.5rem;
	}

	.directory-header h1 {
		font-size: 1.5rem;
	}

	.sort-controls {
		width: 100%;
		justify-content: center;
	}

	.directory-grid {
		grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
		gap: 1rem;
	}

	.directory-item {
		padding: 1rem;
	}

	.folder-icon,
	.file-icon {
		font-size: 2rem;
	}

	.directory-item h3 {
		font-size: 0.9rem;
	}

	.directory-item .item-desc {
		display: none;
	}

	.directory-item .item-type,
	.directory-item .item-date {
		font-size: 0.7rem;
	}
}

@media (max-width: 480px) {
	nav {
		flex-direction: column;
		gap: 0.5rem;
		padding: 0.75rem 1rem;
	}

	.logo {
		font-size: 1.25rem;
	}

	.directory-grid {
		grid-template-columns: repeat(auto-fill, minmax(110px, 1fr));
		gap: 0.75rem;
	}

	.directory-item {
		padding: 0.75rem;
	}

	.folder-icon,
	.file-icon {
		font-size: 1.5rem;
	}

	.directory-item h3 {
		font-size: 0.8rem;
	}

	.sort-controls {
		flex-wrap: wrap;
		padding: 0.4rem 0.6rem;
	}

	.sort-label {
		font-size: 0.75rem;
	}

	.sort-btn {
		padding: 0.3rem 0.6rem;
		font-size: 0.75rem;
	}

	.markdown-page {
		padding: 1.5rem 1rem;
	}

	.markdown-container {
		padding: 1rem;
	}

	.markdown-body h1 {
		font-size: 1.5rem;
	}

	.markdown-body h2 {
		font-size: 1.3rem;
	}

	footer {
		padding: 1.5rem 1rem;
		margin-top: 2rem;
	}

	footer p {
		font-size: 0.8rem;
	}
}

@media (min-width: 1200px) {
	.directory-grid {
		grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
	}
}