:root {
  --bg: #ffffff;
  --text: #1a1a1a;
  --text-muted: #6b6b6b;
  --border: #e6e6e6;
  --accent: #a6321f;
  --accent-hover: #7c2517;
  --pill-bg: #f4f4f2;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #111213;
    --text: #e8e6e3;
    --text-muted: #9a9793;
    --border: #2a2b2c;
    --accent: #e08a6d;
    --accent-hover: #f0a488;
    --pill-bg: #1c1d1e;
  }
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

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

a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
}
a:hover {
  color: var(--accent-hover);
  border-bottom-color: currentColor;
}

.wrap {
  max-width: 700px;
  margin: 0 auto;
  padding: 48px 24px 80px;
}

/* ---------- Language toggle: show/hide by html[data-lang] ---------- */
[data-i18n] { display: none; }
html[data-lang="en"] [data-i18n="en"] { display: inline; }
html[data-lang="zh"] [data-i18n="zh"] { display: inline; }

/* ---------- Header ---------- */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 56px;
  gap: 16px;
  flex-wrap: wrap;
}

.site-nav {
  display: flex;
  gap: 20px;
  font-size: 14px;
}
.site-nav a {
  color: var(--text-muted);
  border-bottom: none;
}
.site-nav a:hover {
  color: var(--text);
}

.lang-toggle {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--pill-bg);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 5px 12px;
  font-size: 13px;
  cursor: pointer;
  color: var(--text-muted);
  font-family: inherit;
}
.lang-toggle .lang-sep { color: var(--border); }
.lang-toggle .lang-opt { padding: 1px 2px; }
html[data-lang="en"] .lang-toggle [data-lang-opt="en"],
html[data-lang="zh"] .lang-toggle [data-lang-opt="zh"] {
  color: var(--text);
  font-weight: 600;
}

/* ---------- Profile ---------- */
.profile {
  display: flex;
  gap: 28px;
  align-items: flex-start;
  margin-bottom: 8px;
}

.avatar {
  width: 128px;
  height: 128px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
}

.profile-text h1 {
  margin: 0 0 6px;
  font-size: 28px;
  letter-spacing: -0.01em;
}

.tagline {
  margin: 0 0 16px;
  color: var(--text-muted);
  font-size: 15px;
}

.profile-text p { margin: 0 0 12px; }

.links {
  display: flex;
  flex-wrap: wrap;
  row-gap: 8px;
  gap: 16px;
  margin-top: 16px;
  font-size: 14px;
}

/* ---------- Sections ---------- */
.block {
  margin-top: 52px;
}

.block h2 {
  font-size: 13px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
  font-weight: 600;
  margin: 0 0 20px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border);
}

/* News */
.news-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.news-list li {
  display: flex;
  gap: 14px;
  margin-bottom: 10px;
  font-size: 15px;
}
.news-date {
  color: var(--text-muted);
  font-variant-numeric: tabular-nums;
  flex-shrink: 0;
}

/* Education */
.edu-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.edu-list li {
  display: flex;
  gap: 14px;
  margin-bottom: 16px;
}
.edu-period {
  flex: 0 0 auto;
  width: 132px;
  color: var(--text-muted);
  font-size: 14px;
  font-variant-numeric: tabular-nums;
}
.edu-degree {
  font-weight: 600;
}
.edu-place {
  color: var(--text-muted);
  font-size: 14px;
  margin-top: 2px;
}

/* Publications / Teaching */
.pub {
  margin-bottom: 28px;
}
.pub-title {
  font-weight: 600;
  font-size: 16px;
  margin-bottom: 4px;
}
.pub-authors {
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 2px;
}
.pub-venue {
  font-size: 13px;
  color: var(--accent);
  margin-bottom: 8px;
}
.pub-summary {
  font-size: 14px;
  color: var(--text-muted);
  margin: 0 0 8px;
}
.pub-links {
  display: flex;
  gap: 14px;
  font-size: 13px;
}
.pub-links a {
  background: var(--pill-bg);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 3px 10px;
}
.pub-links a:hover {
  border-color: var(--accent);
}

/* Contact */
.contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 15px;
}
.contact-list li {
  display: flex;
  gap: 10px;
  margin-bottom: 8px;
}
.contact-label {
  color: var(--text-muted);
  width: 70px;
  flex-shrink: 0;
}

/* ---------- Footer ---------- */
.site-footer {
  margin-top: 64px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-muted);
}

/* ---------- Responsive ---------- */
@media (max-width: 520px) {
  .profile {
    flex-direction: column;
    align-items: flex-start;
  }
  .site-header {
    margin-bottom: 40px;
  }
  .edu-list li {
    flex-direction: column;
    gap: 2px;
  }
  .edu-period {
    width: auto;
  }
}