/* ==========================================================================
   THE SAS LAB - SUSTAINABLE & ADVANCED SYSTEMS LABORATORY
   Department of Chemistry, Indian Institute of Technology Madras (IIT Madras)
   Ultra Modern Academic & Research Laboratory Stylesheet
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800&family=Space+Grotesk:wght@500;700&family=JetBrains+Mono:wght@400;500&display=swap');

:root {
  --primary-navy: #0a192f;
  --primary-navy-dark: #060d17;
  --iitm-maroon: #8b1827;
  --iitm-maroon-dark: #6e131f;
  --iitm-gold: #c59b27;
  --sas-emerald: #10b981;
  --sas-emerald-dark: #059669;
  --sas-teal: #0d9488;
  --sas-cyan: #06b6d4;
  --accent-blue: #2563eb;
  
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-alt: #f1f5f9;
  --text-main: #0f172a;
  --text-muted: #475569;
  --text-subtle: #64748b;
  --border-light: #e2e8f0;
  --border-focus: #10b981;

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -4px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.09), 0 8px 10px -6px rgba(0, 0, 0, 0.04);
  --shadow-glow: 0 0 25px rgba(16, 185, 129, 0.25);
  --shadow-gold-glow: 0 0 25px rgba(217, 119, 6, 0.25);

  --font-sans: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --font-display: 'Space Grotesk', var(--font-sans);
  --font-mono: 'JetBrains Mono', monospace;
}

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

html {
  scroll-behavior: smooth;
  font-family: var(--font-sans);
  color: var(--text-main);
  background-color: var(--bg-main);
  line-height: 1.6;
}

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

/* Typography Enhancements */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  letter-spacing: -0.025em;
  font-weight: 700;
  color: var(--primary-navy);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}
::-webkit-scrollbar-track {
  background: #f1f5f9;
}
::-webkit-scrollbar-thumb {
  background: #cbd5e1;
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: #94a3b8;
}

/* Glassmorphism Classes */
.glass-nav {
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.8);
}

.glass-card {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(226, 232, 240, 0.8);
  box-shadow: var(--shadow-sm);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.glass-card:hover {
  border-color: rgba(16, 185, 129, 0.4);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}

/* Modern Gradient Accents */
.gradient-text-emerald {
  background: linear-gradient(135deg, #059669 0%, #10b981 50%, #06b6d4 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gradient-text-iitm {
  background: linear-gradient(135deg, #0a192f 0%, #8b1827 70%, #c59b27 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.gradient-hero-bg {
  background: radial-gradient(circle at 15% 20%, rgba(16, 185, 129, 0.08) 0%, transparent 45%),
              radial-gradient(circle at 85% 65%, rgba(6, 182, 212, 0.07) 0%, transparent 50%),
              radial-gradient(circle at 50% 10%, rgba(139, 24, 39, 0.04) 0%, transparent 40%),
              linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);
}

.dot-pattern {
  background-image: radial-gradient(#cbd5e1 1.2px, transparent 1.2px);
  background-size: 24px 24px;
}

/* Tab Management & Sub-tabs */
.tab-content {
  display: none;
  animation: fadeIn 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.tab-content.active {
  display: block;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.nav-link {
  position: relative;
  font-weight: 500;
  color: var(--text-muted);
  transition: all 0.2s ease;
  padding: 0.5rem 0.85rem;
  border-radius: 0.5rem;
}

.nav-link:hover {
  color: var(--primary-navy);
  background: rgba(241, 245, 249, 0.8);
}

.nav-link.active {
  color: var(--sas-emerald-dark);
  font-weight: 700;
  background: rgba(16, 185, 129, 0.08);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 20%;
  right: 20%;
  height: 2px;
  background: var(--sas-emerald);
  border-radius: 2px;
}

/* Subtabs buttons */
.subtab-btn {
  transition: all 0.2s ease;
}

.subtab-btn.active {
  background-color: var(--primary-navy);
  color: #ffffff;
  box-shadow: 0 4px 10px rgba(10, 25, 47, 0.2);
}

/* Selected Publication Highlight Card */
.selected-pub-card {
  position: relative;
  background: linear-gradient(145deg, #ffffff 0%, #fcfdfa 100%);
  border: 2px solid #eab308;
  box-shadow: 0 8px 24px rgba(234, 179, 8, 0.12);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.selected-pub-card::before {
  content: 'SELECTED RESEARCH';
  position: absolute;
  top: 0;
  right: 2rem;
  transform: translateY(-50%);
  background: linear-gradient(135deg, #d97706, #f59e0b);
  color: #ffffff;
  font-size: 0.65rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  box-shadow: 0 2px 6px rgba(217, 119, 6, 0.3);
}

.selected-pub-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 32px rgba(234, 179, 8, 0.2);
  border-color: #f59e0b;
}

/* Core Research Pillars Cards */
.pillar-card {
  transition: all 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
}

.pillar-card::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 4px;
  background: linear-gradient(90deg, #10b981, #06b6d4);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.35s ease;
}

.pillar-card:hover::after {
  transform: scaleX(1);
}

.pillar-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-xl);
}

/* Lightbox Modal */
.image-modal {
  display: none;
  position: fixed;
  z-index: 9999;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  overflow: auto;
  background-color: rgba(6, 13, 23, 0.95);
  backdrop-filter: blur(8px);
  align-items: center;
  justify-content: center;
}

.image-modal.active {
  display: flex;
}

.modal-content-img {
  max-width: 92vw;
  max-height: 88vh;
  object-fit: contain;
  border-radius: 0.75rem;
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.7);
  animation: zoomIn 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes zoomIn {
  from {
    transform: scale(0.92);
    opacity: 0;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}

/* Callout Banner - High Contrast & Crisp Readability */
.recruitment-banner {
  background: linear-gradient(135deg, #ecfdf5 0%, #ffffff 55%, #f0fdfa 100%);
  border: 2px solid #10b981;
  box-shadow: 0 12px 30px -5px rgba(16, 185, 129, 0.18), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
  position: relative;
  overflow: hidden;
  color: #0f172a;
}

.recruitment-banner::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -10%;
  width: 320px;
  height: 320px;
  background: radial-gradient(circle, rgba(16, 185, 129, 0.12) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

/* Badge Styles */
.badge-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.25rem 0.65rem;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 9999px;
}

.badge-emerald {
  background-color: #ecfdf5;
  color: #065f46;
  border: 1px solid #a7f3d0;
}

.badge-blue {
  background-color: #eff6ff;
  color: #1e40af;
  border: 1px solid #bfdbfe;
}

.badge-gold {
  background-color: #fefce8;
  color: #854d0e;
  border: 1px solid #fef08a;
}

.badge-purple {
  background-color: #faf5ff;
  color: #6b21a8;
  border: 1px solid #e9d5ff;
}

.badge-maroon {
  background-color: #fff1f2;
  color: #9f1239;
  border: 1px solid #fecdd3;
}

/* Map inset container */
.map-container {
  border-radius: 1rem;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  border: 1px solid #e2e8f0;
}

/* Pulse animation for recruitment indicator */
@keyframes pulseGlow {
  0% {
    box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7);
  }
  70% {
    box-shadow: 0 0 0 10px rgba(16, 185, 129, 0);
  }
  100% {
    box-shadow: 0 0 0 0 rgba(16, 185, 129, 0);
  }
}

.live-indicator {
  width: 10px;
  height: 10px;
  background-color: #10b981;
  border-radius: 50%;
  display: inline-block;
  animation: pulseGlow 2s infinite;
}

/* Print styles */
@media print {
  .glass-nav, footer, .subtab-btn, #search-input, .no-print {
    display: none !important;
  }
  body {
    background: #ffffff !important;
    color: #000000 !important;
  }
  .tab-content {
    display: block !important;
  }
}