/* ===== Huang Lab @ Virginia Tech ===== */

:root {
  --vt-maroon: #861F41;
  --vt-maroon-dark: #641327;
  --vt-orange: #E5751F;
  --ink: #232323;
  --muted: #5b5b5b;
  --line: #e3ddd8;
  --bg: #ffffff;
  --bg-soft: #faf7f5;
  --card: #ffffff;
  --shadow: 0 2px 10px rgba(0,0,0,0.07);
  --radius: 10px;
  --max: 1100px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Segoe UI", -apple-system, BlinkMacSystemFont, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
}

a { color: var(--vt-maroon); text-decoration: none; }
a:hover { text-decoration: underline; }

img { max-width: 100%; display: block; }

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

/* ---------- Header ---------- */

header.site-header {
  background: var(--vt-maroon);
  color: #fff;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0,0,0,0.15);
}

.header-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.brand {
  color: #fff;
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: 0.03em;
  text-decoration: none;
  line-height: 1.2;
}
.brand:hover { text-decoration: none; opacity: 0.92; }
.brand .sub {
  display: block;
  font-weight: 400;
  font-size: 0.72rem;
  letter-spacing: 0.08em;
  opacity: 0.85;
  text-transform: uppercase;
}

nav.main-nav {
  display: flex;
  gap: 4px;
  flex-wrap: wrap;
}

nav.main-nav a {
  color: #f2e3e9;
  text-decoration: none;
  font-size: 0.88rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  padding: 8px 12px;
  border-radius: 6px;
  transition: background 0.15s ease, color 0.15s ease;
}

nav.main-nav a:hover,
nav.main-nav a.active {
  background: rgba(255,255,255,0.14);
  color: #fff;
}

.nav-toggle {
  display: none;
  background: transparent;
  border: none;
  color: #fff;
  font-size: 1.5rem;
  cursor: pointer;
}

@media (max-width: 760px) {
  .nav-toggle { display: block; }
  nav.main-nav {
    display: none;
    flex-direction: column;
    width: 100%;
    background: var(--vt-maroon-dark);
    padding: 8px 0;
  }
  nav.main-nav.open { display: flex; }
  .header-inner { flex-wrap: wrap; }
}

/* ---------- Hero ---------- */

.hero {
  background: linear-gradient(135deg, var(--vt-maroon) 0%, var(--vt-maroon-dark) 100%);
  color: #fff;
  padding: 64px 24px 56px;
  text-align: center;
}

.hero h1 {
  margin: 0 0 14px;
  font-size: clamp(1.6rem, 3.2vw, 2.4rem);
  font-weight: 800;
  letter-spacing: 0.02em;
}

.hero p {
  max-width: 720px;
  margin: 0 auto;
  font-size: 1.05rem;
  color: #f4e6ec;
}

.page-hero {
  background: linear-gradient(135deg, var(--vt-maroon) 0%, var(--vt-maroon-dark) 100%);
  color: #fff;
  padding: 42px 24px;
  text-align: center;
}
.page-hero h1 {
  margin: 0;
  font-size: clamp(1.4rem, 2.6vw, 2rem);
  font-weight: 800;
  letter-spacing: 0.02em;
}
.page-hero p {
  margin: 10px 0 0;
  font-size: 1.05rem;
  color: #f4e6ec;
}

/* ---------- Sections ---------- */

main { display: block; }

section { padding: 48px 0; }
section.soft { background: var(--bg-soft); }

h2.section-title {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--vt-maroon);
  margin: 0 0 8px;
  border-left: 5px solid var(--vt-orange);
  padding-left: 12px;
}

h3.section-sub {
  font-size: 1.15rem;
  font-weight: 700;
  color: var(--vt-maroon-dark);
  margin: 28px 0 6px;
}

.section-intro {
  color: var(--muted);
  margin-bottom: 28px;
  max-width: 780px;
}

/* ---------- Research areas ---------- */

.research-intro {
  max-width: 780px;
  margin: 0 auto 12px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--line);
  text-align: center;
}
.research-intro p {
  color: var(--muted);
  font-size: 1.05rem;
}
.research-intro p:last-child {
  color: var(--vt-maroon-dark);
  font-weight: 700;
  font-size: 0.95rem;
}

.overview-block {
  display: flex;
  align-items: center;
  gap: 40px;
  padding-bottom: 32px;
  margin-bottom: 12px;
  border-bottom: 1px solid var(--line);
}
.overview-text { flex: 1; min-width: 0; }
.overview-diagram {
  flex: 1.1;
  max-width: 444px;
  width: 100%;
  height: auto;
  border-radius: 50%;
  box-shadow: var(--shadow);
}
@media (max-width: 820px) {
  .overview-block { flex-direction: column; }
  .overview-diagram { max-width: 360px; }
}

.research-area {
  display: flex;
  flex-direction: column;
  padding: 40px 0;
  border-bottom: 1px solid var(--line);
}
.research-area:last-child { border-bottom: none; }

.research-area figure {
  margin: 20px auto;
  max-width: 900px;
  width: 100%;
  background: var(--bg-soft);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
}
.research-area figure img { width: 100%; height: auto; display: block; }
.research-area figcaption {
  font-size: 0.78rem;
  color: var(--muted);
  padding: 6px 10px;
}

.research-area h3 {
  color: var(--vt-maroon);
  font-size: 1.25rem;
  margin: 0 0 10px;
}

.projects-box {
  background: var(--bg-soft);
  border-left: 3px solid var(--vt-orange);
  border-radius: 6px;
  padding: 14px 16px;
  margin-top: 20px;
}
.projects-box strong { color: var(--vt-maroon-dark); }
.projects-box ul { margin: 8px 0 0; padding-left: 20px; }
.projects-box li { margin-bottom: 4px; }

/* ---------- Members ---------- */

.member-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(210px, 1fr));
  gap: 22px;
  margin-top: 20px;
}

.member-card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.member-photo {
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  background: var(--bg-soft);
}

.member-info { padding: 14px 16px 18px; flex: 1; }
.member-info h4 { margin: 0 0 2px; font-size: 1rem; color: var(--vt-maroon-dark); }
.member-info .role { font-size: 0.82rem; color: var(--vt-orange); font-weight: 700; margin-bottom: 8px; }
.member-info .edu { font-size: 0.8rem; color: var(--muted); }
.member-info .edu div { margin-bottom: 1px; }
.member-info .next { font-size: 0.8rem; color: var(--muted); margin-top: 6px; font-style: italic; }

.pi-card {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 28px;
  align-items: start;
  background: var(--bg-soft);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
  margin-bottom: 40px;
}
.pi-card img { border-radius: var(--radius); width: 100%; }
.pi-card h3 { margin: 0 0 2px; color: var(--vt-maroon); font-size: 1.4rem; }
.pi-card .role { color: var(--vt-orange); font-weight: 700; margin-bottom: 10px; }
.icon-link { display: inline-flex; align-items: center; gap: 5px; }
.icon-link-svg { flex-shrink: 0; }
@media (max-width: 600px) {
  .pi-card { grid-template-columns: 1fr; }
  .pi-card img { max-width: 220px; margin: 0 auto; }
}

.group-photos {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  margin: 24px 0 8px;
}
.group-photos img {
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  width: 100%;
  height: 220px;
  object-fit: cover;
}

.awards-list {
  columns: 2;
  column-gap: 40px;
  margin-top: 16px;
  padding-left: 20px;
}
.awards-list li { break-inside: avoid; margin-bottom: 10px; font-size: 0.92rem; }
.awards-list strong { color: var(--vt-maroon-dark); }
@media (max-width: 700px) { .awards-list { columns: 1; } }

/* ---------- News ---------- */

.year-block { margin-bottom: 44px; }
.year-heading {
  font-size: 1.6rem;
  font-weight: 800;
  color: #fff;
  background: var(--vt-maroon);
  display: inline-block;
  padding: 6px 18px;
  border-radius: 6px;
  margin-bottom: 20px;
}

.news-item {
  display: grid;
  grid-template-columns: 120px 1fr;
  gap: 18px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}
.news-item:last-child { border-bottom: none; }
.news-date {
  font-weight: 700;
  color: var(--vt-orange);
  font-size: 0.9rem;
  white-space: nowrap;
}
.news-text p { margin: 0 0 8px; }
.news-text a { word-break: break-word; }
.news-photos {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
  gap: 10px;
  margin-top: 10px;
}
.news-photos img {
  border-radius: 8px;
  box-shadow: var(--shadow);
  width: 100%;
  height: 130px;
  object-fit: cover;
}
@media (max-width: 600px) {
  .news-item { grid-template-columns: 1fr; }
}

/* ---------- Publications ---------- */

.pub-year-wrap { counter-reset: pub; }
.pub-list { list-style: none; padding: 0; margin: 16px 0 0; }
.pub-list li {
  counter-increment: pub;
  padding: 12px 0 12px 44px;
  border-bottom: 1px solid var(--line);
  position: relative;
  font-size: 0.94rem;
}
.pub-list li::before {
  content: counter(pub) ".";
  position: absolute;
  left: 0;
  top: 12px;
  color: var(--vt-orange);
  font-weight: 700;
}
.pub-year-note { color: var(--muted); font-size: 0.85rem; }

/* ---------- Join Us ---------- */

.join-card {
  background: var(--bg-soft);
  border-left: 4px solid var(--vt-orange);
  border-radius: var(--radius);
  padding: 28px;
  box-shadow: var(--shadow);
  margin-bottom: 24px;
}
.join-card h3 { margin-top: 0; color: var(--vt-maroon); }

.contact-box {
  background: var(--vt-maroon);
  color: #fff;
  border-radius: var(--radius);
  padding: 28px;
  text-align: left;
}
.contact-box a { color: #fff; text-decoration: underline; }

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

footer.site-footer {
  background: #201014;
  color: #cbb9c0;
  padding: 32px 24px;
  text-align: center;
  font-size: 0.85rem;
  margin-top: 40px;
}
footer.site-footer a { color: #f2c9d6; }

/* ---------- Home page extras ---------- */

.news-teaser {
  background: var(--bg-soft);
  border-radius: var(--radius);
  padding: 24px;
  box-shadow: var(--shadow);
}
.news-teaser ul { margin: 0; padding-left: 20px; }
.news-teaser li { margin-bottom: 10px; }
.more { margin-top: 16px; display: inline-block; font-weight: 700; }
.home-news-date { color: var(--vt-orange); }

.home-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 20px;
}
.home-card {
  background: var(--card);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 22px;
  border-top: 4px solid var(--vt-orange);
}
.home-card h3 { color: var(--vt-maroon); margin-top: 0; }
@media (max-width: 800px) { .home-grid { grid-template-columns: 1fr; } }

.banner-img {
  width: 100%;
  max-height: 360px;
  object-fit: contain;
  background: #fff;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}