/* charlesargon.com — minimalist academic site
   Fonts are self-hosted, never loaded from a CDN, so the site is fast and fully
   functional in China. Source Serif 4 (Latin) and Noto Serif SC (Chinese) are a
   designed pair: Noto Serif CJK's Latin glyphs are Source Serif, so a sentence
   mixing 清代 and "Princeton" keeps one consistent design. Rebuild the subsets
   with build-fonts.py after adding new Chinese characters. Both are SIL OFL. */

/* --- Source Serif 4: Latin, Greek, Cyrillic-free subset --- */
@font-face {
  font-family: "Source Serif 4";
  src: url("/fonts/source-serif-400.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA,
                 U+02DC, U+0300-036F, U+2000-206F, U+2074, U+20AC, U+2122,
                 U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: "Source Serif 4";
  src: url("/fonts/source-serif-600.woff2") format("woff2");
  font-weight: 600;
  font-style: normal;
  font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA,
                 U+02DC, U+0300-036F, U+2000-206F, U+2074, U+20AC, U+2122,
                 U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}
@font-face {
  font-family: "Source Serif 4";
  src: url("/fonts/source-serif-italic-400.woff2") format("woff2");
  font-weight: 400;
  font-style: italic;
  font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA,
                 U+02DC, U+0300-036F, U+2000-206F, U+2074, U+20AC, U+2122,
                 U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* --- Fraunces: display only, for the name and section headings --- */
@font-face {
  font-family: "Fraunces Display";
  src: url("/fonts/fraunces-display.woff2") format("woff2");
  font-weight: 400 700;
  font-style: normal;
  font-display: swap;
  unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA,
                 U+02DC, U+0300-036F, U+2000-206F, U+2074, U+20AC, U+2122,
                 U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD;
}

/* --- Noto Serif SC: only the Han characters this site uses --- */
@font-face {
  font-family: "Noto Serif SC Subset";
  src: url("/fonts/noto-serif-sc-400.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
  unicode-range: U+2E80-9FFF, U+3000-303F, U+F900-FAFF, U+FE30-FE4F, U+FF00-FFEF;
}
@font-face {
  font-family: "Noto Serif SC Subset";
  src: url("/fonts/noto-serif-sc-600.woff2") format("woff2");
  font-weight: 600;
  font-style: normal;
  font-display: swap;
  unicode-range: U+2E80-9FFF, U+3000-303F, U+F900-FAFF, U+FE30-FE4F, U+FF00-FFEF;
}

:root {
  /* One family for the whole site. System faces remain as fallbacks so the page
     is fully readable even if a font file fails to load. */
  --serif: "Source Serif 4", "Noto Serif SC Subset",
           "Iowan Old Style", "Palatino Linotype", Palatino, Georgia,
           "Songti SC", "Source Han Serif SC", "Noto Serif CJK SC",
           "Microsoft YaHei", SimSun, serif;
  /* Small UI text (navigation, labels, captions) uses the same family. Kept as
     its own variable so it can be swapped for a sans in one place later. */
  --ui: var(--serif);
  /* Display face for the name and section headings. Latin only — Han falls
     through to Noto Serif SC, which is deliberate. */
  --display: "Fraunces Display", "Noto Serif SC Subset",
             "Iowan Old Style", Georgia, "Songti SC", "Source Han Serif SC",
             SimSun, serif;

  --bg: #fdfcfa;
  --bg-subtle: #f4f2ee;
  --text: #1c1b19;
  --text-muted: #5f5b54;
  --rule: #ddd9d2;
  --accent: #3f5470;
  --accent-hover: #26374d;

  --measure: 40rem;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #16181c;
    --bg-subtle: #1e2126;
    --text: #e7e4de;
    --text-muted: #a09a91;
    --rule: #32363c;
    --accent: #9db6d6;
    --accent-hover: #c2d4ea;
  }
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.62;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

/* Body text stays at 17px on desktop rather than growing to 18px. The size
   difference between body and headings is what carries the hierarchy; bumping
   the body flattens it again. */
@media (min-width: 40em) {
  html[lang="zh-Hans"] body { font-size: 1.125rem; }
}

/* Chinese pages: Han characters need more leading than Latin text, and Chinese
   type has no italic, so italics are disabled on Chinese passages. Latin words
   inside a Chinese sentence are served by Source Serif via unicode-range, which
   is why mixed text stays visually consistent. */
html[lang="zh-Hans"] body { line-height: 1.95; }
html[lang="zh-Hans"] .role { font-size: 0.875rem; line-height: 1.7; }
html[lang="zh-Hans"] .bib > li,
html[lang="zh-Hans"] .talks > li { line-height: 1.8; }
html[lang="zh-Hans"] em:not([lang]) { font-style: normal; }

/* ---------- Layout ---------- */

.wrap {
  max-width: var(--measure);
  margin: 0 auto;
  padding: 2.5rem 1.375rem 4rem;
}

@media (min-width: 40em) {
  .wrap { padding: 4.5rem 2rem 6rem; }
}

.skip { position: absolute; left: -9999px; }
.skip:focus {
  left: 1rem;
  top: 1rem;
  z-index: 10;
  padding: 0.5rem 0.75rem;
  background: var(--bg);
  border: 1px solid var(--accent);
  border-radius: 3px;
}

/* ---------- Masthead ---------- */

.masthead { margin-bottom: 2.75rem; }

.masthead h1,
.masthead .sitename {
  font-family: var(--display);
  font-size: 2.125rem;
  font-weight: 500;
  letter-spacing: -0.015em;
  line-height: 1.1;
  margin: 0 0 0.5rem;
}

@media (min-width: 40em) {
  .masthead h1,
  .masthead .sitename { font-size: 3rem; letter-spacing: -0.02em; }
}

/* Han has no wonky cut to borrow, so the Chinese name wants a touch less size
   and no negative tracking. */
html[lang="zh-Hans"] .masthead h1,
html[lang="zh-Hans"] .masthead .sitename { letter-spacing: 0; }

@media (min-width: 40em) {
  html[lang="zh-Hans"] .masthead h1,
  html[lang="zh-Hans"] .masthead .sitename { font-size: 2.625rem; }
}

.masthead .sitename a {
  color: var(--text);
  text-decoration: none;
  border: 0;
}
.masthead .sitename a:hover { color: var(--accent); }

.cjk-name {
  font-size: 0.62em;
  font-weight: 400;
  color: var(--text-muted);
  margin-left: 0.45rem;
  white-space: nowrap;
}
/* On the Chinese pages the Latin name is the secondary one. */
html[lang="zh-Hans"] .cjk-name { font-size: 0.72em; }

.role {
  font-family: var(--ui);
  font-size: 0.8125rem;
  line-height: 1.55;
  color: var(--text-muted);
  margin: 0 0 1.6rem;
}

/* ---------- Navigation ---------- */

/* Deliberately not letterspaced small caps. That treatment is the single most
   template-looking thing a minimal site can do; plain sentence case at a
   readable size sits better under a display masthead. */
nav {
  font-family: var(--ui);
  font-size: 0.9375rem;
  padding-top: 0.95rem;
  border-top: 1px solid var(--rule);
}

nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
}

nav a {
  color: var(--text-muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
}
nav a:hover { color: var(--accent); border-bottom-color: var(--accent); }
nav a[aria-current="page"] { color: var(--text); border-bottom-color: var(--rule); }

/* ---------- Side bands ----------
   Left: a detail from a bamboo hanging scroll. Right: a leaf from a Qing
   baojia household register. Both are decorative, so they are aria-hidden in
   the markup and never sit under the text column: they appear only where the
   centred column leaves margin beside it. */

.sideband,
.sideband-right {
  position: fixed;
  top: 0;
  bottom: 0;
  /* Never wider than the empty margin beside the centred text column, so the
     bands shrink with the window instead of vanishing at a fixed breakpoint. */
  width: min(210px, calc((100vw - var(--measure)) / 2 - 1.25rem));
  background-size: cover;
  opacity: 0.95;
  pointer-events: none;
  z-index: 0;
}

.sideband {
  left: 0;
  background-image: url("/bamboo.jpg");
  background-position: center top;
}

.sideband-right {
  right: 0;
  background-image: url("/register.jpg");
  /* The leaf is much wider than the band, so anchor its right-hand edge: that
     keeps the opening columns and the red seal inside the frame. */
  background-position: right top;
}

.wrap { position: relative; z-index: 1; }

/* Below this the margin is too thin for a band to read as anything. */
@media (max-width: 57.99em) {
  .sideband,
  .sideband-right { display: none; }
}

@media (prefers-color-scheme: dark) {
  .sideband,
  .sideband-right { filter: brightness(0.42) contrast(1.05); }
}

/* ---------- Portrait ---------- */

.portrait {
  display: block;
  width: 11.5rem;
  height: auto;
  max-width: 60%;
  border-radius: 2px;
  margin: 0 0 1.5rem;
}

/* On anything wider than a phone the portrait floats and the text wraps around
   it, its top flush with the first line of the opening paragraph. */
@media (min-width: 34em) {
  .portrait {
    float: left;
    width: 10.5rem;
    margin: 0.35rem 1.5rem 0.9rem 0;
  }
  /* Headings after the bio start a clean line rather than wrapping beside it. */
  main h2 { clear: left; }
}

/* ---------- Full-column photograph ---------- */

.wide {
  display: block;
  width: 100%;
  height: auto;
  border-radius: 2px;
  margin: 2rem 0 2.25rem;
}

@media (prefers-color-scheme: dark) {
  .wide { filter: brightness(0.88); }
}

/* ---------- Typography ---------- */

/* The page title is a locator, not a headline — the masthead and the lead do
   the announcing. Setting it small and quiet leaves the section headings free
   to be the largest thing in the text column. */
h1.pagetitle {
  font-family: var(--ui);
  font-size: 0.75rem;
  font-weight: 400;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-muted);
  line-height: 1.3;
  margin: 0 0 1.3rem;
}

html[lang="zh-Hans"] h1.pagetitle { font-size: 0.875rem; letter-spacing: 0.22em; }

h2 {
  font-family: var(--display);
  font-size: 1.5rem;
  font-weight: 400;
  line-height: 1.25;
  margin: 2.4rem 0 0.7rem;
}

html[lang="zh-Hans"] h2 { font-size: 1.375rem; line-height: 1.5; }

/* Small-caps section label, used for bibliography and course groupings. */
.label {
  font-family: var(--ui);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin: 2rem 0 0.875rem;
}

h2 + .label { margin-top: 1.5rem; }
.pagetitle + .label { margin-top: 1.75rem; }

p { margin: 0 0 1.15rem; }

/* A real drop-in, not body text plus 6%. */
.lead { font-size: 1.3125rem; line-height: 1.5; }
html[lang="zh-Hans"] .lead { font-size: 1.1875rem; line-height: 1.8; }

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid color-mix(in srgb, var(--accent) 35%, transparent);
  transition: color 0.12s ease, border-color 0.12s ease;
}
a:hover { color: var(--accent-hover); border-bottom-color: var(--accent-hover); }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

em, i { font-style: italic; }
strong { font-weight: 600; }

.zh { font-size: 0.95em; }
.nowrap { white-space: nowrap; }

/* ---------- Lists ---------- */

ul.plain {
  list-style: none;
  margin: 0 0 1.15rem;
  padding: 0;
}

ul.plain > li { margin-bottom: 0.35rem; }

/* Bibliography entries, with a hanging indent. */
.bib {
  list-style: none;
  margin: 0 0 1.75rem;
  padding: 0;
}

.bib > li {
  margin: 0 0 1.25rem;
  padding-left: 1.5rem;
  text-indent: -1.5rem;
}

.bib .meta {
  display: block;
  text-indent: 0;
  padding-left: 0;
  font-family: var(--ui);
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 0.2rem;
}

.bib .meta a { border-bottom-color: transparent; }
.bib .meta a:hover { border-bottom-color: var(--accent-hover); }

.talks {
  list-style: none;
  margin: 0 0 1.5rem;
  padding: 0;
  font-size: 0.9375em;
}
.talks > li {
  margin: 0 0 0.7rem;
  padding-left: 1.5rem;
  text-indent: -1.5rem;
}
.talks .where { color: var(--text-muted); }

/* Course list */
.courses {
  list-style: none;
  margin: 0 0 1.75rem;
  padding: 0;
}
.courses > li {
  margin: 0 0 1rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--rule);
}
.courses > li:last-child { border-bottom: 0; }
.courses .ctitle { display: block; }
.courses .cmeta {
  display: block;
  font-family: var(--ui);
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-top: 0.15rem;
}

/* ---------- Contact / details block ---------- */

.details {
  margin: 0 0 1.15rem;
  font-family: var(--ui);
  font-size: 0.9375rem;
}

.details div {
  display: flex;
  flex-wrap: wrap;
  gap: 0 0.6rem;
  padding: 0.4rem 0;
  border-bottom: 1px solid var(--rule);
}
.details div:first-child { border-top: 1px solid var(--rule); }

.details dt {
  flex: 0 0 5.5rem;
  color: var(--text-muted);
  font-size: 0.8125rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  padding-top: 0.15rem;
}

.details dd {
  flex: 1 1 12rem;
  margin: 0;
}

/* ---------- CV button ---------- */

.cv-link {
  display: inline-block;
  font-family: var(--ui);
  font-size: 0.875rem;
  padding: 0.55rem 1rem;
  margin: 0.25rem 0 1.5rem;
  background: var(--bg-subtle);
  border: 1px solid var(--rule);
  border-radius: 4px;
  color: var(--text);
}
.cv-link:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--bg-subtle);
}

/* ---------- Footer ---------- */

footer {
  margin-top: 4rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
  font-family: var(--ui);
  font-size: 0.8125rem;
  color: var(--text-muted);
}

footer p { margin: 0 0 0.4rem; }
footer a { color: var(--text-muted); border-bottom-color: var(--rule); }
footer a:hover { color: var(--accent); }

/* ---------- Print ---------- */

@media print {
  :root { --bg: #fff; --text: #000; --text-muted: #444; --accent: #000; }
  nav, .cv-link, .skip, .portrait, .sideband, .sideband-right { display: none; }
  .wrap { max-width: none; padding: 0; }
  a { border: 0; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}