:root {
  --ut-blue: #003f88;
  --ut-teal: #00a6d6;
  --text: #1a1a2e;
  --muted: #5a6a7a;
  --border: #dde3ea;
  --bg: #ffffff;
  --bg-alt: #f5f7fa;
  --tag-bg: #e8f4fb;
  --tag-color: #006699;
  --link: #005aaa;
  --link-hover: #003f88;
  --max-width: 860px;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; scroll-behavior: smooth; }

body {
  font-family: 'Georgia', 'Times New Roman', serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
}

/* ── Layout ─────────────────────────────────── */
.site-header {
  background: var(--ut-blue);
  color: #fff;
  padding: 3rem 2rem 2.5rem;
}

.header-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  align-items: flex-start;
  gap: 2.5rem;
}

.avatar {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  border: 3px solid rgba(255,255,255,0.35);
  background: rgba(255,255,255,0.12);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2.8rem;
  color: rgba(255,255,255,0.8);
  font-family: Georgia, serif;
  letter-spacing: -1px;
}

.header-text h1 {
  font-size: 2.2rem;
  font-weight: normal;
  letter-spacing: -0.5px;
  margin-bottom: 0.2rem;
}

.header-text .role {
  font-size: 1rem;
  opacity: 0.85;
  font-family: 'Arial', sans-serif;
  margin-bottom: 0.5rem;
}

.header-text .affiliation {
  font-size: 0.9rem;
  opacity: 0.7;
  font-family: 'Arial', sans-serif;
}

.header-text .affiliation a {
  color: var(--ut-teal);
  text-decoration: none;
}
.header-text .affiliation a:hover { text-decoration: underline; }

.header-links {
  margin-top: 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
}

.header-links a {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: rgba(255,255,255,0.9);
  text-decoration: none;
  font-family: 'Arial', sans-serif;
  font-size: 0.82rem;
  border: 1px solid rgba(255,255,255,0.3);
  border-radius: 4px;
  padding: 0.25rem 0.7rem;
  transition: background 0.15s, border-color 0.15s;
}
.header-links a:hover {
  background: rgba(255,255,255,0.15);
  border-color: rgba(255,255,255,0.6);
}

/* ── Nav ─────────────────────────────────────── */
nav {
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
}

nav ul {
  max-width: var(--max-width);
  margin: 0 auto;
  list-style: none;
  display: flex;
  gap: 0;
}

nav a {
  display: block;
  padding: 0.85rem 1.2rem;
  color: var(--muted);
  text-decoration: none;
  font-family: 'Arial', sans-serif;
  font-size: 0.88rem;
  border-bottom: 2px solid transparent;
  transition: color 0.15s, border-color 0.15s;
}
nav a:hover { color: var(--ut-blue); border-bottom-color: var(--ut-teal); }

/* ── Main content ────────────────────────────── */
main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem 4rem;
}

section {
  padding-top: 3.5rem;
}

section + section {
  border-top: 1px solid var(--border);
}

h2 {
  font-size: 1.45rem;
  font-weight: normal;
  color: var(--ut-blue);
  margin-bottom: 1.4rem;
  padding-bottom: 0.4rem;
  border-bottom: 2px solid var(--ut-teal);
  display: inline-block;
}

p { margin-bottom: 0.9rem; }

a { color: var(--link); }
a:hover { color: var(--link-hover); }

/* ── Research interests ─────────────────────── */
.interests {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.5rem;
}

.interest-tag {
  background: var(--tag-bg);
  color: var(--tag-color);
  font-family: 'Arial', sans-serif;
  font-size: 0.82rem;
  padding: 0.3rem 0.8rem;
  border-radius: 20px;
  border: 1px solid #b8ddf0;
}

/* ── Publications ────────────────────────────── */
.pub-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1.6rem;
}

.pub-list.compact {
  gap: 0.5rem;
}

.pub-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.pub-year {
  font-family: 'Arial', sans-serif;
  font-size: 0.82rem;
  color: var(--muted);
  min-width: 38px;
  padding-top: 0.15rem;
  text-align: right;
  flex-shrink: 0;
}

.pub-body {}

.pub-title {
  font-size: 0.97rem;
  font-weight: bold;
  font-style: normal;
  color: var(--text);
  margin-bottom: 0.2rem;
  line-height: 1.5;
}

.pub-title a {
  color: inherit;
  text-decoration: none;
}
.pub-title a:hover { text-decoration: underline; color: var(--link); }

.pub-authors {
  font-family: 'Arial', sans-serif;
  font-size: 0.84rem;
  color: var(--muted);
  margin-bottom: 0.2rem;
}

.pub-authors .self { color: var(--text); font-weight: bold; }

.pub-venue {
  font-family: 'Arial', sans-serif;
  font-size: 0.84rem;
  color: var(--muted);
  font-style: italic;
  margin-bottom: 0.4rem;
}

.pub-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.pub-link {
  font-family: 'Arial', sans-serif;
  font-size: 0.76rem;
  padding: 0.15rem 0.55rem;
  border-radius: 3px;
  text-decoration: none;
  border: 1px solid;
  transition: background 0.12s;
}

.pub-link.arxiv  { color: #b31b1b; border-color: #e8b4b4; background: #fdf5f5; }
.pub-link.arxiv:hover  { background: #fce8e8; }
.pub-link.conf   { color: #1a5c1a; border-color: #a8d4a8; background: #f2faf2; }
.pub-link.conf:hover   { background: #e2f4e2; }
.pub-link.thesis { color: #5a3e00; border-color: #d4b87a; background: #fdf8ee; }
.pub-link.thesis:hover { background: #f8edcc; }

.pub-badge {
  display: inline-block;
  font-family: 'Arial', sans-serif;
  font-size: 0.7rem;
  padding: 0.1rem 0.45rem;
  border-radius: 3px;
  margin-left: 0.5rem;
  background: var(--ut-teal);
  color: #fff;
  vertical-align: middle;
  font-style: normal;
}

/* ── News ────────────────────────────────────── */
.news-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}

.news-item {
  display: flex;
  gap: 1rem;
  align-items: baseline;
  font-size: 0.92rem;
}

.news-date {
  font-family: 'Arial', sans-serif;
  font-size: 0.78rem;
  color: var(--muted);
  min-width: 90px;
  flex-shrink: 0;
}

/* ── Contact ─────────────────────────────────── */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  font-family: 'Arial', sans-serif;
  font-size: 0.92rem;
}

.contact-item strong {
  display: block;
  color: var(--ut-blue);
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.25rem;
}

/* ── Footer ──────────────────────────────────── */
footer {
  background: var(--bg-alt);
  border-top: 1px solid var(--border);
  text-align: center;
  padding: 1.5rem 2rem;
  font-family: 'Arial', sans-serif;
  font-size: 0.8rem;
  color: var(--muted);
}

/* ── Responsive ──────────────────────────────── */
@media (max-width: 620px) {
  .header-inner { flex-direction: column; align-items: center; text-align: center; gap: 1.2rem; }
  .header-links { justify-content: center; }
  .contact-grid { grid-template-columns: 1fr; }
  main { padding: 0 1.2rem 3rem; }
  nav a { padding: 0.75rem 0.9rem; font-size: 0.82rem; }
}