/* ============================================================
   yokoxue.github.io — light modern academic style
   Single stylesheet for the whole site. No external fonts, no JS.
   Accent: SYSU green (#00695C / #0a8f7a)
   ============================================================ */

:root {
  --bg:        #ffffff;
  --bg-soft:   #f7f9f9;
  --ink:       #1f2933;
  --ink-soft:  #52616b;
  --ink-mute:  #7b8794;
  --rule:      #e4e9ec;
  --accent:    #00695c;
  --accent-lt: #0a8f7a;
  --tag-bg:    #eef6f4;
  --wrap:      1080px;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter,
               "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- header / nav ---------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--rule);
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 62px;
  flex-wrap: wrap;
}

.brand {
  font-size: 1.06rem;
  font-weight: 650;
  letter-spacing: 0.01em;
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
}
.brand span { color: var(--ink-mute); font-weight: 500; margin-left: 2px; }
.brand:hover { color: var(--accent); }

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  align-items: center;
}

.site-nav a {
  position: relative;
  padding: 6px 0;
  font-size: 0.94rem;
  color: var(--ink-soft);
  text-decoration: none;
  white-space: nowrap;
}
.site-nav a:hover { color: var(--accent); }

.site-nav a.current {
  color: var(--accent);
  font-weight: 600;
}
.site-nav a.current::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -1px;
  height: 2px;
  background: var(--accent);
  border-radius: 2px;
}

/* ---------- page title + sections ---------- */

main { padding: 34px 0 56px; }

h1.page-title {
  margin: 0 0 6px;
  font-size: 2.0rem;
  font-weight: 680;
  letter-spacing: -0.01em;
  line-height: 1.2;
}
h1.page-title .zh { color: var(--ink-mute); font-weight: 500; }

.page-lede {
  margin: 0 0 28px;
  color: var(--ink-soft);
  font-size: 1.03rem;
  max-width: 82ch;
}

h2 {
  margin: 38px 0 14px;
  padding-bottom: 8px;
  font-size: 1.22rem;
  font-weight: 650;
  letter-spacing: -0.005em;
  border-bottom: 1px solid var(--rule);
}
h2:first-of-type { margin-top: 6px; }

h3 {
  margin: 24px 0 8px;
  font-size: 1.03rem;
  font-weight: 650;
  color: var(--accent);
}

p { margin: 0 0 0.9em; }
p:last-child { margin-bottom: 0; }

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 2px; }

hr.sep { border: 0; border-top: 1px solid var(--rule); margin: 34px 0; }

/* ---------- hero (home page) ---------- */

.hero {
  display: grid;
  grid-template-columns: 176px 1fr;
  gap: 30px;
  align-items: start;
  padding-bottom: 26px;
  margin-bottom: 8px;
  border-bottom: 1px solid var(--rule);
}

.hero img {
  width: 100%;
  border-radius: 12px;
  border: 1px solid var(--rule);
  display: block;
}

.hero .role {
  font-weight: 650;
  font-size: 1.06rem;
  margin-bottom: 4px;
}
.hero .affil { color: var(--ink-soft); margin: 0 0 10px; }
.hero .affil a { color: var(--ink-soft); }
.hero .affil a:hover { color: var(--accent); }

.links { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }

.btn {
  display: inline-block;
  padding: 5px 13px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  font-size: 0.9rem;
  color: var(--ink-soft);
  text-decoration: none;
  transition: background .15s, border-color .15s, color .15s;
}
.btn:hover {
  background: var(--tag-bg);
  border-color: var(--accent-lt);
  color: var(--accent);
  text-decoration: none;
}

/* ---------- tags ---------- */

.tag {
  display: inline-block;
  padding: 1px 9px;
  margin-right: 5px;
  background: var(--tag-bg);
  color: var(--accent);
  border-radius: 999px;
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  white-space: nowrap;
  vertical-align: 1px;
}

.badge {
  display: inline-block;
  padding: 2px 8px;
  background: var(--accent);
  color: #fff;
  border-radius: 5px;
  font-size: 0.8rem;
  font-weight: 600;
}

/* ---------- research area cards ---------- */

.areas { display: grid; gap: 14px; margin: 4px 0 0; }

.area {
  padding: 16px 18px;
  background: var(--bg-soft);
  border: 1px solid var(--rule);
  border-radius: 10px;
}
.area h3 { margin: 0 0 6px; color: var(--ink); }
.area p  { margin: 0; color: var(--ink-soft); font-size: 0.97rem; }

/* ---------- publication list ---------- */

ol.pubs, ul.pubs { list-style: none; margin: 0; padding: 0; counter-reset: pub; }

ol.pubs > li, ul.pubs > li {
  position: relative;
  padding: 12px 16px 12px 18px;
  margin-bottom: 10px;
  border-left: 3px solid var(--rule);
  border-radius: 0 8px 8px 0;
  transition: background .15s, border-color .15s;
}
ol.pubs > li:hover, ul.pubs > li:hover {
  background: var(--bg-soft);
  border-left-color: var(--accent-lt);
}
ol.pubs > li p, ul.pubs > li p { margin: 0; }

.pubs .venue { color: var(--ink-soft); font-style: italic; }
.pubs .meta  { color: var(--ink-mute); font-size: 0.88rem; }
.pubs b      { font-weight: 680; }

.smallnote { color: var(--ink-mute); font-size: 0.9rem; }

/* ---------- generic lists ---------- */

ul.tight, ol.tight { margin: 0 0 0.6em; padding-left: 1.25em; }
ul.tight > li, ol.tight > li { margin: 0.3em 0; }
ul.tight ul, ol.tight ol, ul.tight ol, ol.tight ul {
  margin: 0.25em 0 0.4em;
  padding-left: 1.15em;
}
ul.tight ul > li { color: var(--ink-soft); font-size: 0.96rem; }

ul { list-style-type: square; }
ul ul { list-style-type: circle; }

/* ---------- callout ---------- */

.note {
  margin: 16px 0;
  padding: 14px 18px;
  background: var(--tag-bg);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
}
.note p { margin: 0; }
.note em { color: var(--ink); }

/* ---------- funding / two-column definition rows ---------- */

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

.rows > li {
  padding: 11px 0;
  border-bottom: 1px solid var(--rule);
}
.rows > li:last-child { border-bottom: none; }

.rows .row-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 16px;
  flex-wrap: wrap;
}
.rows .row-title { font-weight: 620; }
.rows .row-when  { color: var(--ink-mute); font-size: 0.9rem; white-space: nowrap; }
.rows .row-sub   { color: var(--ink-soft); font-size: 0.96rem; margin-top: 2px; }
.rows .role      { color: var(--accent); font-weight: 600; font-size: 0.88rem; }

/* ---------- figures ---------- */

figure { margin: 18px 0; }
figure img {
  max-width: 100%;
  height: auto;
  display: block;
  border-radius: 10px;
  border: 1px solid var(--rule);
}
figcaption {
  margin-top: 8px;
  color: var(--ink-mute);
  font-size: 0.9rem;
}

/* ---------- photo grid ---------- */

.gallery {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
  margin: 6px 0 0;
}

.gallery figure { margin: 0; }

/* aspect-ratio + object-fit: 无论新照片是横是竖、多大尺寸，
   都裁成一致的 4:3 卡片，网格不会被撑歪 */
.gallery figure img {
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
}

/* ---------- footer ---------- */

.site-footer {
  border-top: 1px solid var(--rule);
  padding: 22px 0 34px;
  color: var(--ink-mute);
  font-size: 0.9rem;
}
.site-footer .wrap {
  display: flex;
  justify-content: space-between;
  gap: 14px;
  flex-wrap: wrap;
}

/* ---------- responsive ---------- */

@media (max-width: 760px) {
  body { font-size: 15.5px; }
  .wrap { padding: 0 18px; }
  .site-header .wrap { min-height: 0; padding-top: 10px; padding-bottom: 10px; }
  .site-nav { gap: 2px 14px; }
  .site-nav a { font-size: 0.9rem; }
  h1.page-title { font-size: 1.6rem; }
  h2 { font-size: 1.12rem; margin-top: 30px; }
  .hero { grid-template-columns: 1fr; gap: 18px; }
  .hero img { max-width: 168px; }
  .gallery { grid-template-columns: 1fr; gap: 16px; }
  ol.pubs > li, ul.pubs > li { padding: 10px 12px 10px 14px; }
  .rows .row-head { gap: 4px; }
}

@media print {
  .site-header, .site-footer { display: none; }
  body { font-size: 11pt; }
  a { color: var(--ink); }
}