:root {
	--bg: #f7f2e8;
	--card: #fffdf7;
	--text: #1c2a2f;
	--muted: #58666b;

	--accent: #2b8c7f;
	--accent2: #4f8edb;
	--accent3: #c9883a;
	--link: #2f6fcb;

	--card-border: rgba(28, 42, 47, 0.12);
	--shadow: 0 12px 34px rgba(17, 24, 39, 0.08);

	--code-bg: rgba(79, 142, 219, 0.08);
	--code-border: rgba(28, 42, 47, 0.14);

	--content-width: 1240px;
	--content-pad: 16px;

	--table-head-bg: rgba(79, 142, 219, 0.12);
	--table-row-alt: rgba(28, 42, 47, 0.03);

	--chip-bg: rgba(28, 42, 47, 0.06);
	--chip-border: rgba(28, 42, 47, 0.12);

	--select: rgba(43, 140, 127, 0.22);

	--topbar: linear-gradient(
		90deg,
		var(--accent),
		var(--accent2),
		var(--accent3)
	);

	--glow1: rgba(79, 142, 219, 0.14);
	--glow2: rgba(43, 140, 127, 0.12);
	--glow3: rgba(201, 136, 58, 0.1);
}

:root.dark {
	--bg: #07040a;
	--card: #120716;
	--text: #fff1f6;
	--muted: #d2b8c4;

	--accent: #ff3d3d;
	--accent2: #a855f7;
	--accent3: #22c55e;
	--link: #ff6aa6;

	--card-border: rgba(255, 241, 246, 0.12);
	--shadow: 0 18px 70px rgba(0, 0, 0, 0.66);

	--code-bg: #0c060e;
	--code-border: rgba(255, 241, 246, 0.14);

	--content-width: 1240px;
	--content-pad: 16px;

	--table-head-bg: rgba(255, 61, 61, 0.14);
	--table-row-alt: rgba(255, 241, 246, 0.05);

	--chip-bg: rgba(255, 241, 246, 0.08);
	--chip-border: rgba(255, 241, 246, 0.14);

	--select: rgba(255, 61, 61, 0.18);

	--topbar: linear-gradient(
		90deg,
		rgba(255, 61, 61, 0.9),
		rgba(168, 85, 247, 0.9)
	);

	--glow1: rgba(255, 61, 61, 0.18);
	--glow2: rgba(168, 85, 247, 0.22);
	--glow3: rgba(34, 197, 94, 0.1);
}

* {
	box-sizing: border-box;
}

html,
body {
	height: 100%;
}

html {
	scroll-behavior: smooth;
}

body {
	margin: 0;
	background: var(--bg);
	color: var(--text);
	font: 16.5px/1.7 system-ui, -apple-system, Segoe UI, Roboto, Ubuntu,
		Cantarell, Noto Sans, Arial;
	isolation: isolate;
}

:root:not(.dark) body::before {
	content: "";
	position: fixed;
	inset: 0;
	z-index: -1;
	pointer-events: none;
	background: linear-gradient(
			180deg,
			rgba(120, 190, 255, 0.26),
			transparent 34%
		),
		radial-gradient(
			1200px 520px at 50% 14%,
			rgba(120, 190, 255, 0.24),
			transparent 62%
		),
		radial-gradient(
			1100px 560px at 20% 24%,
			rgba(60, 170, 140, 0.14),
			transparent 60%
		),
		radial-gradient(
			1000px 520px at 85% 28%,
			rgba(201, 136, 58, 0.1),
			transparent 58%
		),
		radial-gradient(
			1400px 520px at 50% 112%,
			rgba(40, 120, 90, 0.18),
			transparent 62%
		),
		radial-gradient(
			1200px 420px at 30% 118%,
			rgba(25, 80, 60, 0.18),
			transparent 62%
		),
		radial-gradient(
			1200px 420px at 75% 120%,
			rgba(30, 95, 70, 0.16),
			transparent 62%
		);
	background-repeat: no-repeat;
	background-size: cover;
}

:root:not(.dark) body::after {
	content: "";
	position: fixed;
	inset: 0;
	z-index: -1;
	pointer-events: none;
	background-image: radial-gradient(
		rgba(0, 0, 0, 0.035) 1px,
		transparent 1px
	);
	background-size: 3px 3px;
	opacity: 0.35;
	mix-blend-mode: multiply;
}

:root.dark body::before {
	content: "";
	position: fixed;
	inset: 0;
	z-index: -1;
	pointer-events: none;
	background: radial-gradient(
			1200px 750px at 16% -10%,
			var(--glow1),
			transparent 62%
		),
		radial-gradient(950px 650px at 92% 12%, var(--glow2), transparent 58%),
		radial-gradient(900px 550px at 60% 112%, var(--glow3), transparent 60%);
	background-repeat: no-repeat;
	background-size: cover;
}

:root.dark body::after {
	content: none;
}

a {
	color: var(--link);
	text-decoration: none;
	border-bottom: 1px solid transparent;
	transition: border-color 0.15s ease, opacity 0.15s ease;
}

a:hover {
	border-bottom-color: currentColor;
	opacity: 0.95;
}

::selection {
	background: var(--select);
}

.site-header,
.site-footer {
	max-width: var(--content-width);
	margin: 0 auto;
	padding: 20px var(--content-pad);
	display: flex;
	align-items: center;
	justify-content: space-between;
	gap: 12px;
}

.site-header h1 {
	font-size: 22px;
	margin: 0;
	letter-spacing: -0.02em;
}

.site-header nav {
	display: flex;
	align-items: center;
	gap: 12px;
}

.site-header nav a {
	opacity: 0.92;
}

main {
	max-width: var(--content-width);
	margin: 0 auto;
	padding: 24px var(--content-pad);
}

.post-list {
	list-style: none;
	padding-left: 0;
	margin: 0;
}

.post-list li {
	padding: 12px 0;
	border-bottom: 1px solid var(--card-border);
}

.post-link {
	font-weight: 650;
	letter-spacing: -0.01em;
}

.post-date {
	float: right;
	color: var(--muted);
	font-size: 14px;
}

.page {
	display: grid;
	grid-template-columns: 240px 1fr;
	gap: 18px;
	align-items: start;
}

.toc {
	position: sticky;
	top: 18px;
	height: calc(100vh - 36px);
}

.toc-card {
	background: var(--card);
	border: 1px solid var(--card-border);
	border-radius: 14px;
	box-shadow: var(--shadow);
	padding: 12px 12px;
}

.toc-title {
	font-weight: 650;
	letter-spacing: -0.01em;
	margin-bottom: 8px;
}

.toc-links {
	display: flex;
	flex-direction: column;
	gap: 6px;
	max-height: calc(100vh - 120px);
	overflow: auto;
	padding-right: 4px;
}

.toc-links a {
	color: var(--muted);
	border-bottom: none;
	padding: 6px 8px;
	border-radius: 10px;
	transition: background 0.15s ease, color 0.15s ease, opacity 0.15s ease;
}

.toc-links a:hover {
	background: color-mix(in srgb, var(--card) 82%, var(--accent2) 18%);
	color: var(--text);
	opacity: 1;
}

.article {
	position: relative;
	background: var(--card);
	border-radius: 16px;
	padding: 18px;
	border: 1px solid var(--card-border);
	box-shadow: var(--shadow);
	overflow: hidden;
}

.article::before {
	content: "";
	position: absolute;
	left: 0;
	top: 0;
	width: 100%;
	height: 4px;
	background: var(--topbar);
}

.article h1 {
	margin-top: 0;
	letter-spacing: -0.03em;
}

.article h2,
.article h3 {
	letter-spacing: -0.02em;
	scroll-margin-top: 90px;
}

.article h2 {
	margin-top: 26px;
	padding-bottom: 8px;
	border-bottom: 1px solid var(--card-border);
}

.article .meta {
	color: var(--muted);
	font-size: 14px;
	margin-top: -6px;
	margin-bottom: 16px;
}

.page {
	display: grid;
	grid-template-columns: 240px 1fr;
	gap: 20px;
	align-items: start;
}

.toc {
	position: sticky;
	top: 90px;
	align-self: start;
}

.toc-card {
	background: var(--card);
	border: 1px solid var(--card-border);
	border-radius: 14px;
	box-shadow: var(--shadow);
	padding: 12px;
}

.toc-title {
	font-weight: 650;
	margin-bottom: 8px;
}

.toc-links {
	display: flex;
	flex-direction: column;
	gap: 8px;
}

@media (max-width: 860px) {
	.page {
		grid-template-columns: 1fr;
	}
	.toc {
		position: relative;
		top: auto;
	}
}

.back {
	display: inline-block;
	margin-bottom: 16px;
}

hr {
	border: none;
	border-top: 1px solid var(--card-border);
	margin: 18px 0;
}

#theme-toggle {
	background: color-mix(in srgb, var(--card) 88%, var(--accent) 12%);
	color: var(--text);
	border: 1px solid var(--card-border);
	border-radius: 50%;
	width: 32px;
	height: 32px;
	display: inline-flex;
	align-items: center;
	justify-content: center;
	cursor: pointer;
	font-size: 18px;
	transition: transform 0.15s ease, background 0.15s ease, opacity 0.15s ease;
}

#theme-toggle:hover {
	transform: scale(1.05);
	opacity: 0.95;
}

#theme-toggle:active {
	transform: scale(0.95);
}

#theme-toggle .icon {
	display: inline-flex;
	align-items: center;
	justify-content: center;
	width: 18px;
	height: 18px;
}

#theme-toggle svg {
	width: 18px;
	height: 18px;
	fill: none;
	stroke: currentColor;
	stroke-width: 1.75;
	stroke-linecap: round;
	stroke-linejoin: round;
	display: block;
}

#theme-toggle .icon-moon svg {
	fill: currentColor;
	stroke: none;
}

#theme-toggle .icon-moon {
	display: none;
}

:root.dark #theme-toggle .icon-sun {
	display: none;
}

:root.dark #theme-toggle .icon-moon {
	display: inline-flex;
}

#theme-toggle .icon-sun {
	color: #f59e0b;
}

#theme-toggle .icon-moon {
	color: #7c96b8;
}

:root.dark #theme-toggle .icon-sun {
	color: #facc15;
}

:root.dark #theme-toggle .icon-moon {
	color: #a7b8de;
}

pre {
	background: color-mix(in srgb, var(--card) 88%, var(--accent2) 12%);
	border: 1px solid var(--code-border);
	border-radius: 12px;
	padding: 12px 14px;
	overflow-x: auto;
	margin: 18px 0;
}

:root.dark pre {
	background: var(--code-bg);
	border-color: var(--code-border);
}

pre code {
	background: transparent;
	color: var(--text);
	font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas,
		"Liberation Mono", "Courier New", monospace;
	font-size: 0.85rem;
	line-height: 1.55;
}

:root.dark pre code {
	color: #f2ecff;
}

table {
	width: 100%;
	margin: 16px 0;
	border-collapse: collapse;
	background: var(--card);
	border-radius: 12px;
	overflow: hidden;
	border: 1px solid var(--card-border);
	box-shadow: 0 4px 16px rgba(0, 0, 0, 0.25);
}

thead th {
	background: color-mix(in oklab, var(--card) 85%, black 10%);
	color: var(--text);
	text-align: center;
	padding: 10px 12px;
	font-weight: 650;
}

tbody td,
tbody th {
	padding: 10px 12px;
	border-top: 1px solid color-mix(in oklab, var(--card) 65%, black 25%);
	text-align: center;
	vertical-align: top;
}

tbody tr:nth-child(odd) {
	background: color-mix(in oklab, var(--card) 92%, black 4%);
}

:root.dark thead th {
	background: color-mix(in oklab, var(--card) 75%, white 6%);
}

:root.dark tbody td,
:root.dark tbody th {
	border-top-color: color-mix(in oklab, var(--card) 50%, white 14%);
}

td code,
td .katex,
td .math {
	white-space: nowrap;
}

ul,
ol {
	padding-left: 22px;
}

li + li {
	margin-top: 6px;
}

.callout {
	border: 1px solid var(--card-border);
	border-left: 4px solid var(--accent);
	background: color-mix(in srgb, var(--card) 92%, var(--accent) 8%);
	border-radius: 12px;
	padding: 12px 14px;
	margin: 16px 0;
}

.callout strong {
	display: inline-block;
	margin-right: 6px;
}

.callout.note {
	border-left-color: var(--accent2);
	background: color-mix(in srgb, var(--card) 92%, var(--accent2) 8%);
}

.callout.warn {
	border-left-color: var(--accent3);
	background: color-mix(in srgb, var(--card) 92%, var(--accent3) 8%);
}

.callout.danger {
	border-left-color: #ef4444;
	background: color-mix(in srgb, var(--card) 92%, #ef4444 8%);
}

.tag {
	display: inline-flex;
	align-items: center;
	gap: 8px;
	padding: 6px 10px;
	border-radius: 999px;
	border: 1px solid var(--chip-border);
	background: var(--chip-bg);
	color: var(--muted);
	font-size: 0.85rem;
	line-height: 1;
}

.tag::before {
	content: "";
	width: 8px;
	height: 8px;
	border-radius: 999px;
	background: var(--topbar);
}

blockquote {
	margin: 16px 0;
	padding: 10px 14px;
	border-left: 4px solid var(--accent2);
	background: color-mix(in srgb, var(--card) 92%, var(--accent2) 8%);
	border-radius: 12px;
	color: var(--text);
}

@media (max-width: 980px) {
	.page {
		grid-template-columns: 1fr;
	}
	.toc {
		position: relative;
		top: 0;
		height: auto;
	}
}

@media (max-width: 560px) {
	.post-date {
		float: none;
		display: block;
		margin-top: 6px;
	}
	.site-header,
	.site-footer {
		flex-direction: column;
		align-items: flex-start;
	}
}

.chip {
	display: inline-flex;
	align-items: center;
	gap: 8px;
	padding: 6px 10px;
	border-radius: 999px;
	border: 1px solid var(--chip-border);
	background: var(--chip-bg);
	font-size: 0.85rem;
	line-height: 1;
}

.chip.topic {
	color: var(--muted);
	background: var(--chip-bg);
	border-color: var(--chip-border);
}

.chip.tag {
	--tag-color: var(--accent2);
	color: var(--text);
	background: color-mix(in srgb, var(--tag-color) 18%, var(--card));
	border-color: color-mix(in srgb, var(--tag-color) 35%, var(--chip-border));
}

:root.dark .chip.tag {
	background: color-mix(in srgb, var(--tag-color) 24%, var(--card));
	border-color: color-mix(in srgb, var(--tag-color) 40%, var(--chip-border));
	color: var(--text);
}

.chip.topic::before {
	content: "";
	width: 8px;
	height: 8px;
	border-radius: 999px;
	background: var(--topbar);
	opacity: 0.9;
}