/* ─── IMPORT SN PRO FROM GOOGLE FONTS ─── */
@import url('https://fonts.googleapis.com/css2?family=SN+Pro:wght@300;400;500;600;700&display=swap');

/* ─── 3-COLOR PALETTE ─── */
:root {
  --bg-main: #ffffff;
  --bg-alt: #f4f4f4;
  --text-primary: #111111;
  --text-secondary: #555555;
  --border-color: #dddddd;
  --accent-color: #a31f34; 
  --nav-bg: rgba(255, 255, 255, 0.98);
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'SN Pro', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }

html { font-size: 18px; scroll-behavior: smooth; }

body {
  background: var(--bg-main);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

a { color: var(--accent-color); text-decoration: none; font-weight: 500; transition: color 0.2s; }
a:hover { color: var(--text-primary); text-decoration: underline; }

/* ─── NAVIGATION ─── */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
  background: var(--nav-bg);
  border-bottom: 1px solid var(--border-color);
  display: flex; align-items: center; justify-content: space-between;
  padding: 0 3rem; height: 70px;
}

.nav-brand { display: flex; align-items: center; gap: 0.75rem; cursor: pointer; z-index: 1001; }
.nav-logo {
  width: 36px; height: 36px;
  background: var(--accent-color);
  display: flex; align-items: center; justify-content: center;
  font-weight: 700; color: #fff; font-size: 1.2rem;
}
.nav-brand-text { font-size: 1.2rem; font-weight: 700; color: var(--text-primary); text-transform: uppercase; letter-spacing: 0.05em; }

.nav-links { display: flex; align-items: center; gap: 1.5rem; list-style: none; transition: transform 0.3s ease, opacity 0.3s ease; }
.nav-links a {
  color: var(--text-secondary);
  font-size: 0.95rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em;
  position: relative; padding-bottom: 0.2rem;
}
.nav-links a::after {
  content: ''; position: absolute; left: 0; bottom: 0; width: 0; height: 2px; background: var(--accent-color); transition: width 0.2s;
}
.nav-links a:hover::after, .nav-links a.active::after { width: 100%; }
.nav-links a:hover, .nav-links a.active { color: var(--text-primary); text-decoration: none; }

/* Hamburger Menu Toggle (Hidden by default) */
.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-between;
  width: 30px;
  height: 21px;
  cursor: pointer;
  z-index: 1001;
  margin-left: 1rem;
}
.menu-toggle .bar {
  height: 3px;
  width: 100%;
  background-color: var(--text-primary);
  border-radius: 3px;
  transition: all 0.3s ease-in-out;
}

/* ─── PAGE LAYOUT ─── */
main { flex: 1; padding-top: 70px; animation: fadeIn 0.4s ease forwards; }
.content-wrap { max-width: 1000px; margin: 0 auto; padding: 4rem 2rem; }

/* ─── HERO VIEW ─── */
.hero-welcome { padding: 8rem 1rem 6rem; text-align: left; border-bottom: 1px solid var(--border-color); }
.hero-title { font-size: clamp(2.5rem, 5vw, 4rem); color: var(--text-primary); margin-bottom: 1.5rem; font-weight: 300; line-height: 1.1; letter-spacing: -0.02em; }
.hero-acronym { font-size: 1rem; color: var(--accent-color); margin-bottom: 1rem; letter-spacing: 0.2em; font-weight: 600; margin-left: 0.50rem;}
.hero-subtitle { font-size: 1.2rem; color: var(--text-secondary); font-weight: 400; max-width: 600px; margin-left: 2px;}

/* ─── INDEX SPECIFIC OVERRIDES ─── */
.page-index { display: flex; flex-direction: column; height: 100vh; min-height: 100vh; overflow: hidden; }
.page-index main { flex: 1; min-height: auto; display: flex; align-items: center; padding-top: 70px; }
.page-index .hero-welcome { padding: 2rem 1rem; border-bottom: none; }
.hero-quote { margin-bottom: 0; font-size: 1.3rem; line-height: 1.5; font-weight: 300; color: var(--text-primary); text-indent: -0.45em; }

/* ─── RESEARCH VIEW ─── */
.vision-block { margin-bottom: 2rem; padding-bottom: 2rem; border-bottom: 1px solid var(--border-color); }
.vision-text { font-size: 1.15rem; line-height: 1.7; font-weight: 400; color: var(--text-primary); }
.vision-text strong { color: var(--accent-color); font-weight: 600; }
.interests-block { margin-bottom: 4rem; padding-bottom: 2rem; border-bottom: 1px solid var(--border-color); }
.interests-block.no-border { border-bottom: none; padding-bottom: 0; margin-bottom: 2rem; }
.interests-title { font-size: 1rem; font-weight: 700; text-transform: uppercase; color: var(--accent-color); margin-bottom: 1rem; letter-spacing: 0.1em; }
.chip-group { display: flex; flex-wrap: wrap; gap: 0.75rem; margin-top: 1rem; }
.chip { padding: 0.5rem 1rem; font-weight: 500; font-size: 0.95rem; background: var(--bg-alt); border-radius: 4px; border: 1px solid var(--border-color); color: var(--text-primary); }
.research-grid-item { display: grid; grid-template-columns: 300px 1fr; gap: 3rem; margin-bottom: 4rem; align-items: start; }
.research-grid-item img { width: 100%; height: 220px; object-fit: cover; border: 1px solid var(--border-color); filter: grayscale(20%); }
.research-item-body h3 { font-size: 1.5rem; margin-bottom: 0.75rem; color: var(--text-primary); font-weight: 600; }
.research-item-body p { font-size: 1rem; color: var(--text-secondary); margin-bottom: 1rem; }

/* ─── GROUP VIEW ─── */
.group-container { display: flex; flex-direction: column; gap: 4rem; }
.group-card { display: grid; grid-template-columns: 180px 1fr; gap: 3rem; align-items: center; padding-bottom: 3rem; border-bottom: 1px solid var(--border-color); }
.member-avatar { width: 180px; height: 180px; object-fit: cover; border-radius: 4px; border: 1px solid var(--border-color); transition: filter 0.3s; }
.group-card-content h3 { font-size: 1.6rem; color: var(--text-primary); margin-bottom: 0.25rem; font-weight: 600; }
.role-sub { font-size: 1rem; color: var(--accent-color); font-weight: 700; text-transform: uppercase; letter-spacing: 0.05em; margin-bottom: 0.5rem; }
.role-desc { font-size: 1.1rem; color: var(--text-secondary); margin-bottom: 1rem; }
.social-links { display: flex; gap: 0.75rem; }
.symbol-link { display: inline-flex; align-items: center; justify-content: center; width: 36px; height: 36px; border: 1px solid var(--border-color); background: var(--bg-alt); border-radius: 4px; color: var(--text-secondary); transition: all 0.2s ease; }
.symbol-link:hover { background: var(--accent-color); border-color: var(--accent-color); color: #ffffff; }
.symbol-link svg { width: 18px; height: 18px; fill: currentColor; }
.group-section-title { font-size: 1.5rem; margin-bottom: 1rem; color: var(--text-primary); font-weight: 600; }
.group-section-desc { color: var(--text-secondary); }

/* ─── PUBLICATIONS VIEW ─── */
.tab-container { display: flex; flex-wrap: wrap; gap: 1rem; margin-bottom: 2rem; border-bottom: 1px solid var(--border-color); }
.tab-btn { background: none; border: none; padding: 0.5rem 1rem; font-size: 1rem; font-weight: 600; color: var(--text-secondary); cursor: pointer; border-bottom: 2px solid transparent; transition: all 0.2s; }
.tab-btn.active { color: var(--accent-color); border-bottom: 2px solid var(--accent-color); }
.tab-btn:hover { color: var(--text-primary); }
.tab-content { display: none; }
.tab-content.active { display: block; animation: fadeIn 0.3s ease; }
.pub-row { padding: 1.5rem 0; border-bottom: 1px solid var(--border-color); }
.pub-row:last-child { border-bottom: none; }
.pub-title { font-size: 1.1rem; font-weight: 600; color: var(--text-primary); margin-bottom: 0.5rem; line-height: 1.4; }
.pub-authors { font-size: 1rem; color: var(--text-secondary); margin-bottom: 0.25rem; }
.pub-journal { font-style: italic; font-size: 0.95rem; color: var(--text-primary); font-weight: 400; }
.pub-doi { margin-top: 0.25rem; }
.pub-doi span, .pub-doi a { font-size: 0.85rem; word-break: break-all; }
.pub-doi a { text-decoration: underline; }

/* ─── CONTACT / OPPORTUNITIES VIEW ─── */
.contact-clean { padding: 2rem 0; text-align: left; }
.contact-clean h2 { font-size: 2rem; margin-bottom: 1rem; color: var(--text-primary); font-weight: 600; }
.contact-clean p { font-size: 1.1rem; color: var(--text-secondary); margin-bottom: 0.5rem; }
.email-highlight { font-size: clamp(1rem, 4vw, 1.2rem); /*color: var(--text-primary);*/ font-weight: 600; margin-top: 1.5rem; display: inline-block;  word-break: break-all; }
.opportunities-heading { color: var(--accent-color); margin-bottom: 1rem; }
.opportunities-text { font-size: 1.15rem; line-height: 1.7; color: var(--text-primary); }
.opportunities-text a { color: var(--accent-color); font-weight: 600; text-decoration: underline; }

/* ─── TEACHING ─── */
.unified-bullet-list { list-style-type: disc; padding-left: 1.5rem; margin-top: 1rem; }
.unified-bullet-list li { font-size: 1rem; color: var(--text-secondary); margin-bottom: 0.5rem; }

/* ─── FOOTER ─── */
footer { padding: 3rem 2rem; text-align: left; max-width: 1000px; margin: 0 auto; font-size: 0.9rem; color: var(--text-secondary); display: flex; justify-content: space-between; align-items: center; width: 100%; }

@keyframes fadeIn { from { opacity: 0; transform: translateY(5px); } to { opacity: 1; transform: translateY(0); } }

/* ─── RESPONSIVE MEDIA QUERIES ─── */
@media (max-width: 900px) {
  nav { padding: 0 1.5rem; }
  
  /* Mobile Navigation Styles */
  .menu-toggle { display: flex; }
  
  .nav-links {
    position: absolute;
    top: 70px; /* Height of the nav bar */
    left: 0;
    right: 0;
    background-color: var(--nav-bg);
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.05);
    
    /* Animation hidden state */
    transform: translateY(-150%);
    opacity: 0;
    pointer-events: none;
  }

  .nav-links.active-menu {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  /* Hamburger Menu Animation to 'X' */
  .menu-toggle.is-active .bar:nth-child(1) { transform: translateY(9px) rotate(45deg); }
  .menu-toggle.is-active .bar:nth-child(2) { opacity: 0; }
  .menu-toggle.is-active .bar:nth-child(3) { transform: translateY(-9px) rotate(-45deg); }

  /* Page Content Adjustments */
  .research-grid-item, .group-card { grid-template-columns: 1fr; gap: 1.5rem; }
  .research-grid-item img { height: auto; aspect-ratio: 16/9; }
  .member-avatar { height: auto; aspect-ratio: 1/1; max-width: 200px; margin: 0 auto; }
  .group-card-content { text-align: center; }
  .social-links { justify-content: center; }
  
  .content-wrap { padding: 3rem 1.5rem; }
  footer { flex-direction: column; text-align: center; gap: 1rem; }
  
  .tab-container { flex-direction: column; gap: 0; }
  .tab-btn { text-align: left; border-bottom: none; border-left: 2px solid transparent; padding: 0.75rem 1rem; }
  .tab-btn.active { border-bottom: none; border-left: 2px solid var(--accent-color); }
  
  /* Index Page Scrolling Fix */
  .page-index { height: auto; min-height: 100vh; overflow: visible; }
}

@media (max-width: 480px) {
  .hero-title { font-size: 2.2rem; }
  .nav-brand-text { display: none; } /* Show only 'S' logo on very small screens */
  .content-wrap { padding: 2rem 1rem; }
  .member-avatar { max-width: 150px; }
}