/* ==========================================================================
   Long Arc Lab - Lab Website Stylesheet
   Clean, modern academic lab aesthetic
   ========================================================================== */

/* ---------- Reset & Base ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --color-primary: #6b2d5b;
  --color-primary-light: #8b3a6e;
  --color-primary-dark: #4a1942;
  --color-accent: #c06c84;
  --color-accent-light: #d4899c;
  --color-text: #2d2233;
  --color-text-light: #5a4a63;
  --color-text-muted: #8a7e91;
  --color-bg: #ffffff;
  --color-bg-warm: #fdf9fb;
  --color-bg-section: #f7f2f5;
  --color-border: #e8dfe5;
  --color-border-light: #f0eaed;
  --color-warm-gold: #d4a857;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-serif: 'Source Serif 4', Georgia, 'Times New Roman', serif;
  --max-width: 1100px;
  --nav-height: 70px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  font-size: 18px;
  line-height: 1.75;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--color-primary-light);
  text-decoration: none;
  transition: color 0.2s;
}
a:hover {
  color: var(--color-primary-dark);
}

img {
  max-width: 100%;
  height: auto;
}

/* ---------- Navigation ---------- */
.site-nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(255, 255, 255, 0.97);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border-light);
  height: var(--nav-height);
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  line-height: 1.2;
}
.nav-logo-mark {
  color: var(--color-primary);
  flex-shrink: 0;
}
.nav-logo-text {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: -0.02em;
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 0.25rem;
}
.nav-links a {
  display: block;
  padding: 0.5rem 1rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-text-light);
  border-radius: 6px;
  transition: all 0.2s;
}
.nav-links a:hover {
  color: var(--color-primary);
  background: var(--color-bg-section);
}
.nav-links a.active {
  color: var(--color-primary);
  background: rgba(107, 45, 91, 0.08);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  flex-direction: column;
  gap: 5px;
}
.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text);
  transition: all 0.3s;
}
.nav-toggle.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ---------- Hero Section ---------- */
.hero {
  background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 40%, #7b4a8e 100%);
  color: #fff;
  padding: 5rem 2rem;
  text-align: center;
}
.hero-container {
  max-width: var(--max-width);
  margin: 0 auto;
}
.hero h1 {
  font-family: var(--font-serif);
  font-size: 3rem;
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: 1.25rem;
  letter-spacing: -0.02em;
}
.hero p {
  font-size: 1.25rem;
  line-height: 1.75;
  max-width: 750px;
  margin: 0 auto;
  opacity: 0.92;
  font-weight: 300;
}

/* ---------- Section Styles ---------- */
.section {
  padding: 4rem 2rem;
}
.section-alt {
  background: var(--color-bg-section);
}
.section-container {
  max-width: var(--max-width);
  margin: 0 auto;
}
.section-header {
  margin-bottom: 2.5rem;
}
.section-header h2 {
  font-family: var(--font-serif);
  font-size: 2rem;
  font-weight: 600;
  color: var(--color-primary);
  margin-bottom: 0.5rem;
  letter-spacing: -0.01em;
}
.section-header p {
  font-size: 1.1rem;
  color: var(--color-text-light);
}

/* ---------- Page Header ---------- */
.page-header {
  background: var(--color-bg-section);
  border-bottom: 1px solid var(--color-border);
  padding: 3rem 2rem;
  text-align: center;
}
.page-header h1 {
  font-family: var(--font-serif);
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: 0.5rem;
}
.page-header p {
  color: var(--color-text-light);
  font-size: 1.05rem;
  max-width: 600px;
  margin: 0 auto;
}

/* ---------- News / Announcements ---------- */
.announcement {
  background: linear-gradient(135deg, #fdf2f6 0%, #f5e6ed 100%);
  border-left: 4px solid var(--color-accent);
  padding: 1.25rem 1.5rem;
  border-radius: 0 8px 8px 0;
  margin-bottom: 1.5rem;
}
.announcement p {
  margin: 0;
  font-size: 1.05rem;
}
.announcement strong {
  color: var(--color-text);
}

.news-list {
  list-style: none;
}
.news-item {
  display: flex;
  gap: 1.25rem;
  padding: 1.25rem 0;
  border-bottom: 1px solid var(--color-border-light);
}
.news-item:last-child {
  border-bottom: none;
}
.news-date {
  flex-shrink: 0;
  width: 90px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-primary-light);
  padding-top: 2px;
}
.news-content {
  font-size: 1.05rem;
}
.news-content a {
  font-weight: 500;
}

/* ---------- Publication List ---------- */
.pub-list {
  list-style: none;
}
.pub-item {
  padding: 1.5rem 0;
  border-bottom: 1px solid var(--color-border-light);
}
.pub-item:last-child {
  border-bottom: none;
}
.pub-year {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--color-primary-light);
  background: rgba(107, 45, 91, 0.1);
  padding: 0.15rem 0.5rem;
  border-radius: 4px;
  margin-bottom: 0.5rem;
}
.pub-title {
  font-family: var(--font-serif);
  font-size: 1.2rem;
  font-weight: 600;
  color: var(--color-text);
  line-height: 1.4;
  margin-bottom: 0.35rem;
}
.pub-title a {
  color: var(--color-text);
}
.pub-title a:hover {
  color: var(--color-primary-light);
}
.pub-authors {
  font-size: 0.9rem;
  color: var(--color-text-light);
  margin-bottom: 0.25rem;
}
.pub-venue {
  font-size: 0.9rem;
  font-style: italic;
  color: var(--color-text-muted);
  margin-bottom: 0.5rem;
}
.pub-links {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.pub-links a {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-primary-light);
  padding: 0.2rem 0.6rem;
  border: 1px solid var(--color-primary-light);
  border-radius: 4px;
  transition: all 0.2s;
}
.pub-links a:hover {
  background: var(--color-primary-light);
  color: #fff;
}

.pub-abstract {
  margin-top: 0.75rem;
}
.pub-abstract summary {
  cursor: pointer;
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-primary-light);
  padding: 0.25rem 0;
}
.pub-abstract summary:hover {
  color: var(--color-primary-dark);
}
.pub-abstract p {
  margin-top: 0.75rem;
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.7;
  padding: 1rem;
  background: var(--color-bg-section);
  border-radius: 6px;
}

.pub-category {
  margin-top: 3rem;
}
.pub-category h3 {
  font-family: var(--font-serif);
  font-size: 1.3rem;
  font-weight: 600;
  color: var(--color-text);
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--color-primary);
  margin-bottom: 1rem;
  display: inline-block;
}

/* ---------- Tool / Dataset Cards ---------- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 1.5rem;
}
.card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 1.75rem;
  transition: box-shadow 0.2s, transform 0.2s;
}
.card:hover {
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
  transform: translateY(-2px);
}
.card-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 0.2rem 0.6rem;
  border-radius: 4px;
  margin-bottom: 0.75rem;
}
.card-tag.tool {
  background: rgba(39, 174, 96, 0.12);
  color: var(--color-accent);
}
.card-tag.dataset {
  background: rgba(41, 128, 185, 0.12);
  color: var(--color-primary-light);
}
.card-tag.visualization {
  background: rgba(142, 68, 173, 0.12);
  color: #8e44ad;
}
.card h3 {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.5rem;
  line-height: 1.3;
}
.card p {
  font-size: 0.9rem;
  color: var(--color-text-light);
  line-height: 1.6;
  margin-bottom: 1rem;
}
.card-link {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-primary-light);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}
.card-link:hover {
  color: var(--color-primary-dark);
}
.card-link::after {
  content: "\2192";
}

/* ---------- Team ---------- */
.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 2rem;
}
.team-card {
  text-align: center;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 2rem 1.5rem;
  transition: box-shadow 0.2s;
}
.team-card:hover {
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}
.team-photo {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  object-fit: cover;
  margin-bottom: 1rem;
  border: 3px solid var(--color-bg-section);
}
.team-photo-placeholder {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--color-bg-section) 0%, var(--color-border) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1rem;
  font-size: 2.5rem;
  color: var(--color-text-muted);
}
.team-card h3 {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.25rem;
}
.team-role {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--color-primary-light);
  margin-bottom: 0.75rem;
}
.team-bio {
  font-size: 0.88rem;
  color: var(--color-text-light);
  line-height: 1.6;
}
.team-links {
  margin-top: 1rem;
  display: flex;
  justify-content: center;
  gap: 0.75rem;
}
.team-links a {
  color: var(--color-text-muted);
  transition: color 0.2s;
}
.team-links a:hover {
  color: var(--color-primary-light);
}

/* PI card - wider, featured layout */
.team-pi {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  gap: 2.5rem;
  text-align: left;
  padding: 2.5rem;
}
.team-pi .team-photo,
.team-pi .team-photo-placeholder {
  flex-shrink: 0;
  width: 180px;
  height: 180px;
  margin: 0;
}
.team-pi .team-links {
  justify-content: flex-start;
}

/* ---------- Highlight / Featured Cards on Home ---------- */
.featured-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
}
.featured-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  padding: 1.5rem;
  transition: box-shadow 0.2s;
}
.featured-card:hover {
  box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}
.featured-card h4 {
  font-family: var(--font-serif);
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: 0.5rem;
  line-height: 1.35;
}
.featured-card p {
  font-size: 0.95rem;
  color: var(--color-text-light);
  line-height: 1.6;
}
.featured-card .pub-venue {
  margin-top: 0.5rem;
}

/* ---------- Research Areas ---------- */
.research-areas {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}
.research-area {
  padding: 1.5rem;
  border-radius: 10px;
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.15);
}
.research-area h3 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}
.research-area p {
  font-size: 1rem;
  opacity: 0.85;
  line-height: 1.65;
}

/* Hero variant for research areas */
.hero .research-areas {
  margin-top: 2.5rem;
  text-align: left;
}

/* ---------- View All Link ---------- */
.view-all {
  margin-top: 2rem;
  text-align: center;
}
.view-all a {
  display: inline-block;
  padding: 0.65rem 2rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
  border-radius: 6px;
  transition: all 0.2s;
}
.view-all a:hover {
  background: var(--color-primary);
  color: #fff;
}

/* ---------- Join Banner ---------- */
.join-banner {
  background: linear-gradient(135deg, var(--color-primary) 0%, #7b4a8e 100%);
  color: #fff;
  padding: 3.5rem 2rem;
  text-align: center;
}
.join-banner h2 {
  font-family: var(--font-serif);
  font-size: 1.85rem;
  font-weight: 600;
  margin-bottom: 1rem;
}
.join-banner p {
  font-size: 1.1rem;
  max-width: 700px;
  margin: 0 auto 1.5rem;
  opacity: 0.9;
  line-height: 1.75;
}
.join-banner a.btn {
  display: inline-block;
  padding: 0.7rem 2rem;
  font-weight: 600;
  font-size: 0.9rem;
  background: #fff;
  color: var(--color-primary);
  border-radius: 6px;
  transition: all 0.2s;
}
.join-banner a.btn:hover {
  background: rgba(255,255,255,0.9);
  transform: translateY(-1px);
}

/* ---------- Footer ---------- */
.site-footer {
  background: var(--color-text);
  color: rgba(255,255,255,0.7);
  padding: 3rem 2rem 1.5rem;
}
.footer-container {
  max-width: var(--max-width);
  margin: 0 auto;
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
  margin-bottom: 2rem;
}
.footer-col h4 {
  color: #fff;
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}
.footer-col p,
.footer-col a {
  font-size: 0.88rem;
  line-height: 1.6;
  color: rgba(255,255,255,0.6);
}
.footer-col a:hover {
  color: #fff;
}
.footer-social {
  display: flex;
  gap: 1rem;
}
.footer-social a {
  color: rgba(255,255,255,0.5);
  transition: color 0.2s;
}
.footer-social a:hover {
  color: #fff;
}
.footer-bottom {
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 1.5rem;
  text-align: center;
}
.footer-bottom p {
  font-size: 0.8rem;
  color: rgba(255,255,255,0.4);
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }
  .nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: #fff;
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: 1rem;
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  }
  .nav-links.open {
    display: flex;
  }

  .hero {
    padding: 3rem 1.5rem;
  }
  .hero h1 {
    font-size: 1.85rem;
  }
  .hero p {
    font-size: 1rem;
  }

  .section {
    padding: 2.5rem 1.25rem;
  }

  .page-header {
    padding: 2rem 1.25rem;
  }
  .page-header h1 {
    font-size: 1.75rem;
  }

  .card-grid,
  .featured-grid {
    grid-template-columns: 1fr;
  }

  .team-grid {
    grid-template-columns: 1fr;
  }
  .team-pi {
    flex-direction: column;
    text-align: center;
  }
  .team-pi .team-links {
    justify-content: center;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .news-item {
    flex-direction: column;
    gap: 0.25rem;
  }
  .news-date {
    width: auto;
  }
}

@media (max-width: 480px) {
  .hero h1 {
    font-size: 1.5rem;
  }
  .research-areas {
    grid-template-columns: 1fr;
  }
}

/* ---------- Utilities ---------- */
.text-center { text-align: center; }
.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }