/* yucheng.is: one stylesheet for every page.
   Colours are the blog's (formerly src/styles/global.css); type and layout borrow
   from damianplayer.com: serif display, mono labels, big numbers.
   Nav and footer markup is stamped into every page by scripts/chrome.mjs. */

@font-face { font-family: "Instrument Serif"; font-style: normal; font-weight: 400; font-display: swap; src: url(/fonts/instrument-serif-latin-400-normal.woff2) format("woff2"); }
@font-face { font-family: "Instrument Serif"; font-style: italic; font-weight: 400; font-display: swap; src: url(/fonts/instrument-serif-latin-400-italic.woff2) format("woff2"); }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 300; font-display: swap; src: url(/fonts/ibm-plex-mono-latin-300-normal.woff2) format("woff2"); }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 400; font-display: swap; src: url(/fonts/ibm-plex-mono-latin-400-normal.woff2) format("woff2"); }
@font-face { font-family: "IBM Plex Mono"; font-style: normal; font-weight: 500; font-display: swap; src: url(/fonts/ibm-plex-mono-latin-500-normal.woff2) format("woff2"); }

:root {
	--bg: oklch(98.48% 0 0);
	--fg: oklch(26.99% 0.0096 235.05);
	--muted: oklch(52% 0.01 235);
	--link: oklch(55.44% 0.0431 185.69);
	--accent: oklch(55.27% 0.195 19.06);
	--strong: oklch(18.15% 0 0);
	--quote: oklch(55.27% 0.195 19.06);
	--border: oklch(90% 0 0);
	--card: oklch(96% 0 0);
	--serif: "Instrument Serif", "Songti SC", "Noto Serif SC", "Source Han Serif SC", Georgia, serif;
	--mono: "IBM Plex Mono", ui-monospace, SFMono-Regular, Menlo, "PingFang SC", monospace;
	--sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
	--wide: 1120px;
	--text: 700px;
	color-scheme: light;
	accent-color: var(--accent);
}
html[data-theme="dark"] {
	--bg: oklch(23.64% 0.0045 248);
	--fg: oklch(83.54% 0 264);
	--muted: oklch(66% 0 264);
	--link: oklch(70.44% 0.1133 349);
	--accent: oklch(70.91% 0.1415 163.7);
	--strong: oklch(94.66% 0 0);
	--quote: oklch(94.8% 0.106 136.49);
	--border: oklch(32% 0.005 248);
	--card: oklch(27% 0.005 248);
	color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { scrollbar-gutter: stable; -webkit-text-size-adjust: 100%; }
body {
	margin: 0; background: var(--bg); color: var(--fg);
	font: 16px/1.7 var(--sans);
	min-height: 100vh; display: flex; flex-direction: column;
}
main { flex: 1; width: 100%; }
img { max-width: 100%; height: auto; }
a { color: inherit; }
:target { scroll-margin-top: 90px; }
@view-transition { navigation: auto; }

.skip { position: absolute; left: -9999px; }
.skip:focus { left: 16px; top: 16px; z-index: 200; background: var(--bg); padding: 8px 12px; }

/* labels: the mono small caps used everywhere */
.label, .eyebrow {
	font-family: var(--mono); font-size: 12px; font-weight: 400;
	letter-spacing: 0.12em; text-transform: uppercase; color: var(--muted);
}
.wrap { max-width: var(--wide); margin: 0 auto; padding: 0 32px; }
.narrow { max-width: var(--text); margin: 0 auto; padding: 0 24px; }
.serif { font-family: var(--serif); font-weight: 400; }
.u-accent {
	text-decoration: underline; text-decoration-color: var(--accent);
	text-decoration-thickness: 1px; text-underline-offset: 6px;
}

/* ---------- nav ---------- */
nav.site-nav {
	position: sticky; top: 0; z-index: 100;
	display: flex; justify-content: space-between; align-items: center; gap: 20px;
	padding: 14px 32px;
	background: color-mix(in oklch, var(--bg) 86%, transparent);
	-webkit-backdrop-filter: blur(16px); backdrop-filter: blur(16px);
	border-bottom: 1px solid var(--border);
	font-family: var(--mono);
}
nav.site-nav .sn-name {
	font-family: var(--serif); font-size: 24px; line-height: 1;
	color: var(--strong); text-decoration: none; white-space: nowrap;
}
nav.site-nav .sn-links { display: flex; align-items: center; gap: 26px; margin: 0; padding: 0; list-style: none; }
nav.site-nav .sn-links a, nav.site-nav button {
	display: inline-flex; align-items: center; min-height: 36px;
	font: 12px var(--mono); letter-spacing: 0.12em; text-transform: uppercase;
	color: var(--muted); text-decoration: none; white-space: nowrap;
	background: none; border: 0; padding: 0; cursor: pointer;
}
nav.site-nav .sn-links a:hover, nav.site-nav .sn-links a[aria-current="page"], nav.site-nav button:hover { color: var(--strong); }
nav.site-nav .sn-lang { display: inline-flex; gap: 8px; }
nav.site-nav .sn-lang [aria-current="true"] { color: var(--accent); }
nav.site-nav .sn-theme svg { width: 16px; height: 16px; }
html:not([data-theme="dark"]) .sn-theme .moon, html[data-theme="dark"] .sn-theme .sun { display: none; }

/* ---------- footer ---------- */
footer.site-footer {
	display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center;
	gap: 14px 32px; padding: 28px 32px; margin-top: 96px;
	border-top: 1px solid var(--border);
	font: 11px var(--mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted);
}
footer.site-footer p { margin: 0; }
footer.site-footer a { color: var(--fg); text-decoration: none; }
footer.site-footer a:hover { color: var(--accent); }
footer.site-footer .sf-links { display: flex; flex-wrap: wrap; gap: 20px; }

/* ---------- home ---------- */
.hero { padding-block: 120px 72px; }
.hero h1 {
	font-family: var(--serif); font-weight: 400; color: var(--strong);
	font-size: clamp(52px, 9vw, 116px); line-height: 0.98; letter-spacing: -0.015em;
	margin: 24px 0 28px;
}
.hero h1 em { font-style: italic; color: var(--accent); }
.hero .lede { font-size: clamp(18px, 2vw, 21px); max-width: 640px; margin: 0 0 36px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 14px; }
.btn {
	display: inline-flex; align-items: center; gap: 8px; min-height: 44px; padding: 0 18px;
	font: 13px var(--mono); letter-spacing: 0.06em; text-decoration: none;
	border: 1px solid var(--border); color: var(--strong); border-radius: 2px;
	transition: border-color .2s, color .2s;
}
.btn:hover { border-color: var(--accent); color: var(--accent); }
.btn.primary { background: var(--strong); color: var(--bg); border-color: var(--strong); }
.btn.primary:hover { background: var(--accent); border-color: var(--accent); color: var(--bg); }

.section { padding-block: 72px; border-top: 1px solid var(--border); }
.section-head { display: grid; grid-template-columns: 64px 1fr; gap: 0 16px; margin-bottom: 40px; }
.section-head .num { font: 12px var(--mono); color: var(--accent); padding-top: 10px; }
.section-head h2 {
	font-family: var(--serif); font-weight: 400; color: var(--strong);
	font-size: clamp(32px, 4.4vw, 48px); line-height: 1.08; margin: 0;
}
.section-head p { grid-column: 2; margin: 10px 0 0; color: var(--muted); }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(190px, 1fr)); border-top: 1px solid var(--border); border-left: 1px solid var(--border); }
.stat { padding: 28px 24px 24px; border-right: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.stat .v { font-family: var(--serif); font-size: clamp(48px, 6vw, 72px); line-height: 1; color: var(--strong); white-space: nowrap; }
.stat .v sup { font-size: 0.5em; color: var(--accent); vertical-align: 0.6em; margin-left: 2px; }
.stat .k { margin-top: 12px; }
.stats-note { margin-top: 16px; font: 12px var(--mono); color: var(--muted); }

.logos { display: grid; grid-template-columns: repeat(3, 1fr); border-top: 1px solid var(--border); border-left: 1px solid var(--border); }
.logo-cell {
	display: flex; flex-direction: column; justify-content: space-between; gap: 22px;
	min-height: 150px; padding: 24px; border-right: 1px solid var(--border); border-bottom: 1px solid var(--border);
}
.logo-cell .mark { height: 34px; display: flex; align-items: center; }
.logo-cell .mark { gap: 10px; }
.logo-cell .mark img { max-height: 30px; max-width: 150px; width: auto; filter: brightness(0); opacity: .82; }
html[data-theme="dark"] .logo-cell .mark img { filter: brightness(0) invert(1); opacity: .9; }
.logo-cell .mark img.tile, html[data-theme="dark"] .logo-cell .mark img.tile { filter: grayscale(1); opacity: .9; border-radius: 6px; }
.logo-cell .mark .word.sm { font-size: 22px; }
.logo-cell .mark .word { font-family: var(--serif); font-size: 26px; color: var(--strong); line-height: 1; }
.logo-cell .name { font-size: 15px; color: var(--strong); }
.logo-cell .out { font: 12px var(--mono); color: var(--accent); letter-spacing: .04em; }

.work-list { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--border); }
.work-list li { border-bottom: 1px solid var(--border); }
.work-list a { display: grid; grid-template-columns: 64px 1fr auto; gap: 16px; padding: 28px 0; text-decoration: none; }
.work-list .idx { font: 12px var(--mono); color: var(--muted); padding-top: 8px; }
.work-list h3 { font-family: var(--serif); font-weight: 400; font-size: 32px; line-height: 1.1; margin: 0 0 8px; color: var(--strong); }
.work-list p { margin: 0; max-width: 640px; }
.work-list .arrow { font-family: var(--mono); color: var(--muted); padding-top: 8px; transition: color .2s, transform .2s; }
.work-list a:hover h3 { color: var(--accent); }
.work-list a:hover .arrow { color: var(--accent); transform: translate(2px, -2px); }

.post-list { list-style: none; margin: 0; padding: 0; border-top: 1px solid var(--border); }
.post-list li { border-bottom: 1px solid var(--border); }
.post-list a { display: grid; grid-template-columns: 130px 1fr; gap: 16px; padding: 16px 0; text-decoration: none; align-items: baseline; }
.post-list time { font: 12px var(--mono); color: var(--muted); letter-spacing: .04em; }
.post-list .t { font-size: 17px; color: var(--strong); }
.post-list a:hover .t { color: var(--accent); }
.more { display: inline-block; margin-top: 20px; font: 12px var(--mono); letter-spacing: .1em; text-transform: uppercase; color: var(--strong); }

.contact h2 { font-family: var(--serif); font-weight: 400; font-size: clamp(44px, 7vw, 84px); line-height: 1; margin: 0 0 32px; color: var(--strong); }
.contact-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 0; border-top: 1px solid var(--border); border-left: 1px solid var(--border); }
.contact-grid a { display: block; padding: 24px; border-right: 1px solid var(--border); border-bottom: 1px solid var(--border); text-decoration: none; }
.contact-grid .t { font-family: var(--serif); font-size: 26px; color: var(--strong); margin-top: 6px; }
.contact-grid a:hover .t { color: var(--accent); }

/* ---------- page heads (writing, about, thesis) ---------- */
.page-head { padding-block: 96px 40px; }
.page-head h1 { font-family: var(--serif); font-weight: 400; color: var(--strong); font-size: clamp(44px, 7vw, 80px); line-height: 1.02; margin: 16px 0 16px; }
.page-head p { font-size: 19px; max-width: 640px; margin: 0; }
.year { margin-top: 48px; }
.year h2 { font: 12px var(--mono); letter-spacing: .12em; color: var(--accent); margin: 0 0 8px; }

/* ---------- prose (posts, about, thesis) ---------- */
.post-head { padding-block: 88px 32px; }
.post-head h1 { font-family: var(--serif); font-weight: 400; color: var(--strong); font-size: clamp(38px, 5.6vw, 60px); line-height: 1.08; margin: 16px 0 18px; }
.post-head .meta { display: flex; flex-wrap: wrap; gap: 6px 18px; }
.post-head .desc { font-size: 19px; color: var(--muted); margin: 0 0 20px; }
.prose { font-size: 17px; line-height: 1.8; overflow-wrap: break-word; }
.prose > * + * { margin-top: 1.1em; }
.prose p, .prose ul, .prose ol, .prose blockquote, .prose pre, .prose table, .prose figure { margin: 1.1em 0 0; }
.prose h2, .prose h3, .prose h4 { color: var(--strong); line-height: 1.25; scroll-margin-top: 90px; }
.prose h2 { font-family: var(--serif); font-weight: 400; font-size: 34px; margin: 2em 0 0; }
.prose h3 { font-size: 21px; margin: 1.8em 0 0; }
.prose h4 { font-size: 17px; margin: 1.6em 0 0; }
.prose h2 a.anchor, .prose h3 a.anchor, .prose h4 a.anchor { text-decoration: none; color: var(--muted); margin-left: 8px; opacity: 0; font-family: var(--mono); font-size: .6em; }
.prose h2:hover a.anchor, .prose h3:hover a.anchor, .prose h4:hover a.anchor { opacity: 1; }
.prose a { text-decoration: underline; text-decoration-color: color-mix(in oklch, var(--link) 70%, transparent); text-underline-offset: 3px; }
.prose a:hover { text-decoration-color: var(--link); text-decoration-thickness: 2px; }
.prose strong { color: var(--strong); }
.prose ul, .prose ol { padding-left: 1.4em; }
.prose li + li { margin-top: .35em; }
.prose li > ul, .prose li > ol { margin-top: .35em; }
.prose blockquote { border-left: 2px solid var(--quote); padding: 2px 0 2px 18px; color: var(--fg); font-style: normal; margin-left: 0; }
.prose blockquote p:first-child { margin-top: 0; }
.prose hr { border: 0; border-top: 1px dashed var(--border); margin: 2.4em 0; }
.prose img { display: block; margin: 1.4em auto 0; border-radius: 2px; }
.prose table { width: 100%; border-collapse: collapse; font-size: 15px; display: block; overflow-x: auto; }
.prose th, .prose td { border-bottom: 1px solid var(--border); padding: 8px 10px; text-align: left; vertical-align: top; }
.prose th { color: var(--strong); font-weight: 600; }
.prose code { font-family: var(--mono); font-size: .88em; }
.prose :not(pre) > code { background: var(--card); padding: .1em .35em; border-radius: 3px; }
.prose pre { padding: 16px 18px; border-radius: 4px; overflow-x: auto; font-size: 14px; line-height: 1.65; border: 1px solid var(--border); }
.prose pre code { background: none; padding: 0; }
.shiki, .shiki span { color: var(--shiki-light); background-color: var(--shiki-light-bg); }
html[data-theme="dark"] .shiki, html[data-theme="dark"] .shiki span { color: var(--shiki-dark); background-color: var(--shiki-dark-bg); }
.prose .footnotes { font-size: 15px; margin-top: 3em; border-top: 1px solid var(--border); padding-top: 1em; }

.toc { margin: 8px 0 40px; padding: 16px 18px; border: 1px solid var(--border); }
.toc summary { cursor: pointer; }
.toc ol { list-style: none; margin: 10px 0 0; padding: 0; font-size: 15px; }
.toc ol ol { padding-left: 16px; }
.toc li { margin: 4px 0; }
.toc a { text-decoration: none; color: var(--fg); }
.toc a:hover { color: var(--accent); }

.post-foot { margin-top: 56px; padding-top: 24px; border-top: 1px solid var(--border); display: flex; flex-wrap: wrap; justify-content: space-between; gap: 12px; }
.post-foot a { font: 12px var(--mono); letter-spacing: .08em; text-transform: uppercase; text-decoration: none; }
.post-foot a:hover { color: var(--accent); }
.tags { display: flex; flex-wrap: wrap; gap: 8px; }
.tags span { font: 11px var(--mono); color: var(--muted); }

/* admonitions (markup from the old remark-admonitions plugin) */
.admonition { --c: var(--quote); border-left: 2px solid var(--c); padding: 14px 18px; background: color-mix(in oklch, var(--c) 6%, transparent); }
.admonition-title { margin: 0 !important; font: 12px var(--mono); letter-spacing: .12em; text-transform: uppercase; color: var(--c); font-weight: 500; }
.admonition-content > :first-child { margin-top: 8px; }
.admonition[data-admonition-type="note"] { --c: oklch(70.7% 0.165 254.62); }
.admonition[data-admonition-type="tip"] { --c: oklch(76.8% 0.233 130.85); }
.admonition[data-admonition-type="important"] { --c: oklch(71.4% 0.203 305.5); }
.admonition[data-admonition-type="caution"] { --c: oklch(75% 0.183 55.93); }
.admonition[data-admonition-type="warning"] { --c: oklch(63.7% 0.237 25.33); }

/* github card (static: no client-side fetch) */
.github-card { border: 1px solid var(--border); padding: 14px 18px; }
.github-card a { font-family: var(--mono); }

/* ---------- small screens ---------- */
@media (max-width: 720px) {
	.wrap { padding: 0 20px; }
	nav.site-nav { padding: 10px 20px; gap: 12px; }
	nav.site-nav .sn-name { font-size: 20px; }
	nav.site-nav .sn-links { gap: 14px; }
	nav.site-nav .sn-links a, nav.site-nav button { font-size: 11px; letter-spacing: .08em; }
	nav.site-nav .sn-hide-sm { display: none; }
	.hero { padding-block: 72px 48px; }
	.section { padding-block: 56px; }
	.stats { grid-template-columns: repeat(2, 1fr); }
	.stat { padding: 20px 16px; }
	.stat .v { font-size: 40px; white-space: nowrap; }
	.section-head { grid-template-columns: 1fr; }
	.section-head .num { padding: 0 0 6px; }
	.section-head p { grid-column: 1; }
	.work-list a { grid-template-columns: 1fr auto; }
	.work-list .idx { display: none; }
	.post-list a { grid-template-columns: 1fr; gap: 2px; }
	.logos { grid-template-columns: repeat(2, 1fr); }
	.logo-cell { min-height: 130px; padding: 18px; }
	footer.site-footer { padding: 24px 20px; }
	.prose { font-size: 16.5px; }
}
.cover { display: block; width: 100%; margin: 0 0 32px; border-radius: 2px; }
.indent { max-width: var(--text); margin-left: 80px; }
@media (max-width: 720px) { .indent { margin-left: 0; } }
.logo-cell, .stat { min-width: 0; }
.logo-cell .mark img { max-width: min(150px, 100%); }
@media (max-width: 720px) { .stat .v { font-size: 36px; } }