:root {
  --bg: #ffffff;
  --surface: #ffffff;
  --surface-soft: #f9fafb;
  --fg: #111827;
  --muted: #4b5563;
  --accent: #2563eb;
  --accent-soft: #eff6ff;
  --border: #e5e7eb;
  --border-strong: #d1d5db;
  --radius-lg: 18px;
  --radius-md: 12px;
  --shadow-soft: 0 12px 30px rgba(15, 23, 42, 0.06);
}

/* Basic reset-ish */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

/* Links */
a {
  color: var(--accent);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

/* Top bar / navigation */
.topbar {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid rgba(229, 231, 235, 0.9);
}

.topbar-inner {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0.6rem 1.25rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.site-title a {
  font-weight: 700;
  letter-spacing: 0.09em;
  font-size: 0.9rem;
  text-transform: uppercase;
  color: #111827;
}

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

.nav-link {
  font-size: 0.88rem;
  padding: 0.25rem 0.8rem;
  border-radius: 999px;
  color: var(--muted);
  border: 1px solid transparent;
  transition:
    background 0.15s ease,
    color 0.15s ease,
    border-color 0.15s ease;
}

.nav-link:hover {
  background: var(--accent-soft);
  color: var(--accent);
  border-color: #bfdbfe;
}

.nav-link.active {
  background: var(--accent);
  color: #ffffff;
  border-color: var(--accent);
}

/* Page container */
.page {
  max-width: 1040px;
  margin: 0 auto;
  padding: 2.2rem 1.4rem 3.4rem;
}

/* ========== HOME LAYOUT ========== */

.home-grid {
  display: grid;
  grid-template-columns: minmax(0, 260px) minmax(0, 1fr);
  gap: 3rem;
  align-items: flex-start;
}

@media (max-width: 800px) {
  .home-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

/* Left column */
.home-left {
  text-align: center;
}

.home-name {
  font-size: 2.7rem;
  line-height: 1.05;
  font-weight: 600;
  margin: 0 0 1.2rem;
}

.home-photo {
  width: 220px;
  height: 220px;
  border-radius: 50%;
  object-fit: cover;
  background: #e5e7eb;
  display: block;
  margin: 0 auto 1rem;
  box-shadow: 0 14px 34px rgba(148, 163, 184, 0.6);
}

.home-icons {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin-top: 0.4rem;
}

/* circular icon buttons */
.icon-pill {
  width: 32px;
  height: 32px;
  border-radius: 999px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #ffffff;
  border: 1px solid rgba(209, 213, 219, 0.9);
  box-shadow: 0 8px 18px rgba(148, 163, 184, 0.35);
  font-size: 1rem;
  color: #111827;
  text-decoration: none;
  transition:
    transform 0.12s ease,
    box-shadow 0.12s ease,
    border-color 0.12s ease,
    background 0.12s ease,
    color 0.12s ease;
}

.icon-pill i {
  line-height: 1;
}

.icon-pill:hover {
  transform: translateY(-1px);
  box-shadow: 0 12px 26px rgba(129, 140, 248, 0.45);
  border-color: #a5b4fc;
  background: #eef2ff;
  color: #1d4ed8;
}

/* LinkedIn pill uses same class */
.icon-pill-text i {
  font-size: 0.92rem;
}

/* Contact block under icons */
.home-contact {
  margin-top: 1.1rem;
  font-size: 0.9rem;
  color: var(--muted);
}
.home-contact-small {
  font-size: 0.82rem;
}

/* Tag pills */
.tag-row {
  margin-top: 1.1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  justify-content: center;
}

.tag-pill {
  font-size: 0.78rem;
  padding: 0.12rem 0.6rem;
  border-radius: 999px;
  background: var(--surface-soft);
  border: 1px solid var(--border-strong);
  color: var(--muted);
}

/* Right column */
.home-right {
  font-size: 0.98rem;
}

.home-right p {
  margin-top: 0;
  margin-bottom: 1rem;
}

.home-list {
  margin-top: 0.2rem;
  margin-bottom: 1rem;
  padding-left: 1.2rem;
}
.home-list li + li {
  margin-top: 0.35rem;
}

/* ========== HOME SECTIONS ========== */

.home-section {
  margin-top: 2.4rem;
}

/* section title with accent bar */
.section-title {
  font-size: 1.15rem;
  font-weight: 600;
  margin: 0 0 0.8rem;
  color: #111827;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}

.section-title::before {
  content: "";
  width: 3px;
  height: 20px;
  border-radius: 999px;
  background: linear-gradient(180deg, #2563eb, #60a5fa);
}

/* two-column block */
.home-two-col {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.4rem;
}

@media (max-width: 800px) {
  .home-two-col {
    grid-template-columns: 1fr;
  }
}

.home-interests {
  margin: 0.3rem 0 0;
  padding-left: 1.1rem;
  font-size: 0.95rem;
}
.home-interests li + li {
  margin-top: 0.4rem;
}

/* Recent news */

.news-card {
  background: var(--surface-soft);
  border-radius: 16px;
  border: 1px solid var(--border);
  padding: 0.9rem 1.1rem;
}

.news-list {
  list-style: none;
  margin: 0;
  padding-left: 0;
  font-size: 0.95rem;
}

.news-list li {
  padding: 0.35rem 0;
  border-bottom: 1px solid rgba(229, 231, 235, 0.9);
}
.news-list li:last-child {
  border-bottom: none;
}

.news-year {
  font-weight: 600;
  color: #4f46e5;
  margin-right: 0.4rem;
}

/* Highlights & honors */

.home-highlights,
.home-pubs {
  list-style: none;
  padding-left: 0;
  margin: 0.4rem 0 0;
}

.home-highlights li {
  display: flex;
  gap: 0.75rem;
  padding: 0.55rem 0;
  border-bottom: 1px solid var(--border);
}
.home-highlights li:last-child {
  border-bottom: none;
}

.home-bullet {
  margin-top: 0.35rem;
  width: 8px;
  height: 8px;
  border-radius: 999px;
  background: #2563eb;
  box-shadow: 0 0 0 3px #dbeafe;
  flex-shrink: 0;
}

/* Selected publications on home */

.home-pubs li {
  padding: 0.55rem 0;
  border-bottom: 1px solid var(--border);
}
.home-pubs li:last-child {
  border-bottom: none;
}

.home-pub-title {
  font-weight: 600;
}

.home-pub-meta {
  font-size: 0.9rem;
  color: var(--muted);
}

.home-pub-links a + a::before {
  content: "·";
  color: var(--muted);
  margin: 0 0.3rem;
}

.home-more {
  margin-top: 0.6rem;
  font-size: 0.9rem;
}

/* Stats strip */

.stats-section {
  margin-top: 2.4rem;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1.1rem;
}

@media (max-width: 900px) {
  .stats-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (max-width: 540px) {
  .stats-grid {
    grid-template-columns: 1fr 1fr;
    gap: 0.9rem;
  }
}

.stat-card {
  background: #ffffff;
  border-radius: 22px;
  padding: 1.2rem 0.6rem;
  box-shadow: 0 16px 40px rgba(129, 140, 248, 0.18);
  text-align: center;
}

.stat-number {
  font-size: 2.1rem;
  font-weight: 700;
  color: #7c3aed;
  margin-bottom: 0.35rem;
}

.stat-label {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  color: #0f766e;
  text-transform: uppercase;
  line-height: 1.35;
}

.stats-note {
  margin-top: 0.7rem;
  font-size: 0.82rem;
}

/* ========== SHARED STYLES ========== */

.section {
  margin-top: 2rem;
}

.section-card {
  background: var(--surface);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  padding: 1.05rem 1.25rem;
  box-shadow: var(--shadow-soft);
  margin-top: 0.6rem;
}

.section-card + .section-card {
  margin-top: 0.8rem;
}

.lead {
  font-size: 0.97rem;
  color: var(--muted);
  max-width: 54rem;
}

.badge {
  display: inline-block;
  padding: 0.08rem 0.6rem;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  font-size: 0.78rem;
  color: var(--muted);
  margin-right: 0.35rem;
  margin-top: 0.2rem;
  background: var(--surface-soft);
}

.pub {
  margin-bottom: 0.95rem;
  font-size: 0.95rem;
}

.pub-title {
  font-weight: 600;
}

.pub-meta {
  font-size: 0.88rem;
  color: var(--muted);
}

.pub-links {
  font-size: 0.88rem;
  margin-left: 0.25rem;
}

.pub-links a + a::before {
  content: "·";
  color: var(--muted);
  margin: 0 0.3rem;
}

ul {
  margin: 0.4rem 0 0.3rem;
  padding-left: 1.15rem;
}
li + li {
  margin-top: 0.25rem;
}

.muted {
  color: var(--muted);
  font-size: 0.9rem;
}

/* Footer */

.footer {
  border-top: 1px solid rgba(229, 231, 235, 0.9);
  margin-top: 2.4rem;
  padding-top: 0.9rem;
  font-size: 0.83rem;
  color: var(--muted);
  text-align: center;
}

.footer-sep {
  margin: 0 0.3rem;
}

/* hero heading on inner pages */
main .hero-heading:not(.home-hero) {
  font-size: 1.8rem;
}

/* ========== RESEARCH PAGE SPECIFIC ========== */

.research-grid {
  display: flex;
  flex-direction: column;
  gap: 1.6rem;
  margin-top: 0.6rem;
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.research-card {
  height: 100%;
}

/* row: image left, text right */
.research-theme {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

@media (max-width: 750px) {
  .research-theme {
    flex-direction: column;
  }
}

.research-figure {
  flex-shrink: 0;
}

.research-figure img {
  width: 210px;
  max-width: 40vw;
  height: 180px;
  object-fit: cover;
  border-radius: 12px;
  display: block;
}

/* body on the right */
.research-body {
  flex: 1;
}

/* text styles */
.research-title {
  margin-top: 0;
  margin-bottom: 0.25rem;
  font-size: 1.02rem;
}

.research-tagline {
  margin-top: 0;
  margin-bottom: 0.6rem;
  font-size: 0.88rem;
}

.research-list {
  margin: 0.3rem 0 0.5rem;
  padding-left: 1rem;
  font-size: 0.93rem;
}
.research-list li + li {
  margin-top: 0.3rem;
}

.research-mini-pubs {
  margin-top: 0.4rem;
  font-size: 0.87rem;
}

.mini-pub {
  margin-top: 0.15rem;
}

/* pills row for core areas */
.pill-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 0.4rem;
}

.pill {
  font-size: 0.8rem;
  padding: 0.14rem 0.6rem;
  border-radius: 999px;
  background: var(--surface-soft);
  border: 1px solid var(--border-strong);
  color: var(--muted);
}

/* subtitles in research sections */
.research-subtitle {
  margin-top: 0;
  margin-bottom: 0.3rem;
  font-size: 1rem;
}

/* ===== Methods & tools visual cards ===== */

.methods-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.4rem;
  margin-top: 0.5rem;
}

@media (max-width: 800px) {
  .methods-grid {
    grid-template-columns: 1fr;
  }
}

.methods-card {
  position: relative;
}

.methods-header {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  margin-bottom: 0.4rem;
}

.methods-icon {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: #eef2ff;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #4f46e5;
  flex-shrink: 0;
  box-shadow: 0 6px 18px rgba(129, 140, 248, 0.35);
  font-size: 1rem;
}

.methods-icon-ml {
  background: #ecfeff;
  color: #0f766e;
  box-shadow: 0 6px 18px rgba(45, 212, 191, 0.35);
}

.methods-sub {
  font-size: 0.85rem;
  color: var(--muted);
}

/* tool badges with icons */
.tool-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.6rem;
}

.tool-badge {
  font-size: 0.78rem;
  padding: 0.16rem 0.55rem;
  border-radius: 999px;
  border: 1px solid var(--border-strong);
  background: var(--surface-soft);
  color: var(--muted);
  display: inline-flex;
  align-items: center;
  gap: 0.28rem;
}

.tool-badge i {
  font-size: 0.8rem;
  line-height: 1;
}