/* Stylesheet for Dr. Vagishwari Murugesan Professional Website */

/* --- Custom Properties & Tokens --- */
:root {
  /* Color Palette (Clean Light Tech-Teal) */
  --primary: #0f2b48;       /* Deep clinical navy for primary texts & headers */
  --primary-hover: #1e3a5f;
  --secondary: #0d9488;     /* Tech teal for buttons, icons, highlights */
  --accent: #14b8a6;        /* Bright active cyan for tags & interactive states */
  --accent-light: #ccfbf1;  /* Soft teal backgrounds */
  
  /* Neutral Color Palette */
  --bg-main: #f3f8fa;       /* Very light, soothing ice-blue background */
  --bg-white: #ffffff;
  --text-dark: #1e293b;     /* Dark charcoal for body readability */
  --text-muted: #64748b;    /* Slate grey for secondary descriptions */
  --border-light: rgba(13, 148, 136, 0.12); /* Subtle teal border tint */
  
  /* Glassmorphism Configuration (Light Aesthetic) */
  --glass-bg: rgba(255, 255, 255, 0.75);
  --glass-border: rgba(255, 255, 255, 0.9);
  --glass-shadow: 0 10px 30px -10px rgba(15, 43, 72, 0.08);
  --glass-blur: blur(16px);
  
  /* Typography */
  --font-heading: 'Outfit', -apple-system, sans-serif;
  --font-body: 'Inter', -apple-system, sans-serif;
  
  /* Layout Spacing */
  --spacing-section: 6rem;
  --border-radius: 16px;
  --transition-speed: 0.3s;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-body);
  background-color: var(--bg-main);
  color: var(--text-dark);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  color: var(--primary);
  font-weight: 600;
  line-height: 1.25;
}

a {
  text-decoration: none;
  color: inherit;
  transition: all var(--transition-speed) ease;
}

/* --- Custom Components & Global Styling Elements --- */
.section-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.section-header {
  text-align: center;
  margin-bottom: 4rem;
}

.section-title {
  font-size: 2.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 0.75rem;
  position: relative;
}

.section-underline {
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--secondary), var(--accent));
  margin: 0 auto 1.5rem auto;
  border-radius: 2px;
}

.section-subtitle {
  font-size: 1.1rem;
  color: var(--text-muted);
  max-width: 600px;
  margin: 0 auto;
}

/* --- Premium Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.85rem 2rem;
  font-size: 1rem;
  font-weight: 600;
  border-radius: 30px;
  cursor: pointer;
  transition: all var(--transition-speed) cubic-bezier(0.4, 0, 0.2, 1);
  border: none;
  font-family: var(--font-heading);
}

.btn-primary {
  background: linear-gradient(135deg, var(--secondary), var(--accent));
  color: var(--bg-white);
  box-shadow: 0 4px 15px rgba(13, 148, 136, 0.25);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(13, 148, 136, 0.35);
}

.btn-secondary {
  background-color: transparent;
  color: var(--primary);
  border: 2px solid rgba(15, 43, 72, 0.15);
}

.btn-secondary:hover {
  background-color: rgba(15, 43, 72, 0.05);
  border-color: var(--primary);
}

.btn-full {
  width: 100%;
}

/* --- Header / Navigation Bar --- */
.main-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background-color: rgba(243, 248, 250, 0.8);
  backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--border-light);
  transition: all var(--transition-speed) ease;
}

.main-header.scrolled {
  background-color: rgba(255, 255, 255, 0.9);
  box-shadow: var(--glass-shadow);
}

.nav-container {
  max-width: 1300px;
  margin: 0 auto;
  padding: 1.25rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  flex-direction: column;
}

.logo-text {
  font-family: var(--font-heading);
  font-size: 1.35rem;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--primary);
}

.logo-subtitle {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--secondary);
}

.nav-menu {
  display: flex;
  align-items: center;
}

.nav-list {
  list-style: none;
  display: flex;
  align-items: center;
  gap: 2.25rem;
}

.nav-link {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--text-dark);
}

.nav-link:hover {
  color: var(--secondary);
}

.nav-btn {
  background: var(--primary);
  color: var(--bg-white) !important;
  padding: 0.6rem 1.4rem;
  border-radius: 20px;
  font-weight: 600;
}

.nav-btn:hover {
  background: var(--secondary);
  box-shadow: 0 4px 12px rgba(13, 148, 136, 0.2);
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
}

/* --- Hero Section --- */
.hero-section {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 8rem 0 4rem 0;
  overflow: hidden;
  background: radial-gradient(circle at 80% 20%, rgba(20, 184, 166, 0.08) 0%, transparent 50%),
              radial-gradient(circle at 10% 80%, rgba(15, 118, 110, 0.04) 0%, transparent 40%);
}

.hero-bg-waves {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  z-index: 1;
  pointer-events: none;
}

.wave-svg {
  display: block;
  width: 100%;
  height: auto;
}

.hero-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 4rem;
  align-items: center;
  position: relative;
  z-index: 2;
}

.credentials-badge {
  display: inline-block;
  padding: 0.4rem 1rem;
  background-color: var(--accent-light);
  color: var(--secondary);
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  border-radius: 20px;
  margin-bottom: 1.5rem;
  border: 1px solid rgba(13, 148, 136, 0.2);
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 0.25rem;
}

.hero-credentials {
  font-family: var(--font-heading);
  font-size: 1.6rem;
  color: var(--secondary);
  font-weight: 400;
  margin-bottom: 2rem;
}

.hero-subtitle {
  font-size: 1.15rem;
  color: var(--text-dark);
  margin-bottom: 2rem;
  font-weight: 400;
  max-width: 580px;
}

.hero-tag-container {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 3rem;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 1rem;
  background-color: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--border-light);
  border-radius: 20px;
  font-size: 0.85rem;
  font-weight: 550;
  color: var(--primary);
  box-shadow: 0 2px 8px rgba(15, 43, 72, 0.03);
}

.tag-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--accent);
  margin-right: 8px;
}

.hero-actions {
  display: flex;
  gap: 1.25rem;
}

/* --- Hero Glass Card --- */
.hero-visual-content {
  display: flex;
  justify-content: center;
}

.glass-profile-card {
  background-color: var(--glass-bg);
  border: 1px solid var(--glass-border);
  border-radius: var(--border-radius);
  box-shadow: var(--glass-shadow);
  backdrop-filter: var(--glass-blur);
  padding: 2.5rem;
  width: 100%;
  max-width: 380px;
  text-align: center;
  position: relative;
  transition: transform 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

.glass-profile-card:hover {
  transform: translateY(-8px);
}

.glass-card-header {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-bottom: 2rem;
}

.pulse-indicator {
  width: 8px;
  height: 8px;
  background-color: var(--secondary);
  border-radius: 50%;
  position: relative;
}

.pulse-indicator::after {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  border-radius: 50%;
  background-color: var(--secondary);
  animation: pulse 1.8s infinite;
}

@keyframes pulse {
  0% { transform: scale(1); opacity: 0.8; }
  100% { transform: scale(3.5); opacity: 0; }
}

.card-status-text {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.avatar-container {
  width: 100px;
  height: 100px;
  background: radial-gradient(circle, var(--accent-light) 0%, rgba(255, 255, 255, 0.8) 100%);
  border: 2px dashed rgba(13, 148, 136, 0.3);
  border-radius: 50%;
  margin: 0 auto 1.5rem auto;
  display: flex;
  align-items: center;
  justify-content: center;
}

.avatar-svg {
  width: 50px;
  height: 50px;
}

.card-name {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.card-title {
  font-size: 0.9rem;
  color: var(--secondary);
  font-weight: 600;
  margin-bottom: 2rem;
}

.card-stats {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
  margin-bottom: 2rem;
}

.stat-item {
  flex: 1;
  text-align: center;
}

.stat-label {
  display: block;
  font-size: 0.75rem;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 4px;
}

.stat-val {
  font-size: 0.85rem;
  font-weight: 700;
}

.text-accent {
  color: var(--secondary);
}

.stat-divider {
  width: 1px;
  height: 35px;
  background-color: var(--border-light);
}

.cpso-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--secondary);
}

.cpso-link:hover {
  color: var(--primary);
  text-decoration: underline;
}

.external-icon {
  stroke-width: 2px;
}

/* --- About Biography Section --- */
.about-section {
  padding: var(--spacing-section) 0;
  background-color: var(--bg-white);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 5rem;
  align-items: center;
}

.about-bio-text {
  font-size: 1.05rem;
  color: var(--text-dark);
}

.about-bio-text p {
  margin-bottom: 1.5rem;
}

.about-bio-text p:last-child {
  margin-bottom: 0;
}

.lead-text {
  font-size: 1.25rem;
  color: var(--primary);
  font-weight: 500;
  line-height: 1.5;
}

.specs-card {
  background-color: var(--bg-main);
  border: 1px solid var(--border-light);
  border-radius: var(--border-radius);
  padding: 2.5rem;
}

.specs-title {
  font-size: 1.5rem;
  margin-bottom: 2rem;
  position: relative;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--border-light);
}

.specs-list {
  list-style: none;
}

.specs-list li {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.75rem;
}

.specs-list li:last-child {
  margin-bottom: 0;
}

.spec-bullet {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--secondary);
  margin-top: 6px;
  flex-shrink: 0;
  box-shadow: 0 0 0 4px var(--accent-light);
}

.spec-details strong {
  display: block;
  font-size: 1.05rem;
  color: var(--primary);
}

.spec-details span {
  font-size: 0.9rem;
  color: var(--text-muted);
}

/* --- Core Specializations (Interests) --- */
.clinical-interests {
  padding: var(--spacing-section) 0;
}

.interests-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.interest-card {
  background-color: var(--glass-bg);
  border: 1px solid var(--glass-border);
  box-shadow: var(--glass-shadow);
  border-radius: var(--border-radius);
  padding: 2.5rem;
  transition: all var(--transition-speed) ease;
}

.interest-card:hover {
  transform: translateY(-6px);
  border-color: rgba(13, 148, 136, 0.3);
  box-shadow: 0 15px 35px -10px rgba(13, 148, 136, 0.12);
}

.card-icon-container {
  width: 60px;
  height: 60px;
  border-radius: 12px;
  background-color: var(--accent-light);
  color: var(--secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.75rem;
}

.card-icon-container svg {
  width: 32px;
  height: 32px;
}

.interest-card-title {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.interest-card-text {
  font-size: 0.95rem;
  color: var(--text-dark);
  margin-bottom: 1.5rem;
}

.card-highlights {
  list-style: none;
  border-top: 1px solid var(--border-light);
  padding-top: 1.25rem;
}

.card-highlights li {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  margin-bottom: 0.5rem;
}

.card-highlights li::before {
  content: "✔";
  color: var(--secondary);
  margin-right: 8px;
  font-weight: 700;
}

.card-highlights li:last-child {
  margin-bottom: 0;
}

/* --- Timeline Section --- */
.timeline-section {
  padding: var(--spacing-section) 0;
  background-color: var(--bg-white);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.timeline-container {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
  padding: 2rem 0;
}

.timeline-line {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 4px;
  background: linear-gradient(180deg, var(--accent), var(--secondary), rgba(13, 148, 136, 0.1));
  transform: translateX(-50%);
  border-radius: 2px;
}

.timeline-item {
  position: relative;
  width: 50%;
  padding: 0 3rem;
  margin-bottom: 4rem;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-item:nth-child(even) {
  left: 50%;
}

.timeline-item:nth-child(odd) {
  left: 0;
}

.timeline-dot {
  position: absolute;
  top: 0;
  left: 100%;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background-color: var(--bg-white);
  border: 4px solid var(--secondary);
  transform: translate(-50%, 0);
  z-index: 5;
  box-shadow: 0 0 0 5px rgba(13, 148, 136, 0.15);
}

.timeline-dot.current-dot {
  background-color: var(--accent);
  border-color: var(--primary);
  box-shadow: 0 0 0 6px var(--accent-light);
}

.timeline-item:nth-child(even) .timeline-dot {
  left: 0;
}

.timeline-date {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--secondary);
  margin-bottom: 0.5rem;
}

.timeline-item:nth-child(odd) {
  text-align: right;
}

.timeline-content {
  background-color: var(--bg-main);
  border: 1px solid var(--border-light);
  border-radius: var(--border-radius);
  padding: 2rem;
  box-shadow: var(--glass-shadow);
  transition: transform 0.3s ease;
}

.timeline-content:hover {
  transform: scale(1.02);
}

.timeline-category {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 750;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--secondary);
  margin-bottom: 0.5rem;
}

.timeline-item-title {
  font-size: 1.25rem;
  font-weight: 750;
  margin-bottom: 0.25rem;
}

.timeline-institution {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 1rem;
}

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

/* --- Publications Bibliography Section --- */
.publications-section {
  padding: var(--spacing-section) 0;
}

.publications-filter-container {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-bottom: 3.5rem;
}

.filter-btn {
  background-color: var(--bg-white);
  border: 1px solid var(--border-light);
  color: var(--text-dark);
  padding: 0.65rem 1.5rem;
  font-size: 0.9rem;
  font-weight: 600;
  border-radius: 25px;
  cursor: pointer;
  font-family: var(--font-heading);
  transition: all var(--transition-speed) ease;
  box-shadow: 0 2px 6px rgba(0,0,0,0.02);
}

.filter-btn:hover {
  border-color: var(--secondary);
  color: var(--secondary);
}

.filter-btn.active {
  background: var(--primary);
  color: var(--bg-white);
  border-color: var(--primary);
  box-shadow: 0 4px 12px rgba(15, 43, 72, 0.15);
}

.publications-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
}

.pub-card {
  background-color: var(--bg-white);
  border: 1px solid var(--border-light);
  border-radius: var(--border-radius);
  padding: 2rem;
  display: flex;
  flex-direction: column;
  box-shadow: var(--glass-shadow);
  transition: all var(--transition-speed) ease;
}

.pub-card:hover {
  transform: translateY(-4px);
  border-color: var(--secondary);
}

.pub-badge {
  display: inline-block;
  align-self: flex-start;
  font-size: 0.7rem;
  font-weight: 700;
  text-transform: uppercase;
  padding: 0.3rem 0.75rem;
  border-radius: 12px;
  margin-bottom: 1.25rem;
}

.article-badge { background-color: var(--accent-light); color: var(--secondary); }
.abstract-badge { background-color: #e0f2fe; color: #0369a1; }
.chapter-badge { background-color: #fef3c7; color: #b45309; }

.pub-title {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
  line-height: 1.4;
}

.pub-authors {
  font-size: 0.9rem;
  color: var(--text-dark);
  margin-bottom: 0.5rem;
}

.pub-authors strong {
  color: var(--primary);
  font-weight: 600;
}

.pub-journal {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-top: auto;
  font-style: italic;
}

/* --- Advocacy & Patient Initiatives --- */
.initiatives-section {
  padding: var(--spacing-section) 0;
  background-color: var(--bg-white);
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

.initiatives-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.initiative-card {
  background-color: var(--bg-main);
  border: 1px solid var(--border-light);
  border-radius: var(--border-radius);
  padding: 2.5rem;
  display: flex;
  flex-direction: column;
}

.init-card-title {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 1rem;
}

.init-card-desc {
  font-size: 0.95rem;
  color: var(--text-dark);
  margin-bottom: 2rem;
  line-height: 1.7;
}

.init-link {
  margin-top: auto;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--secondary);
}

.init-link:hover {
  color: var(--primary);
  text-decoration: underline;
}

/* --- Contact & Clinic Info --- */
.contact-section {
  padding: var(--spacing-section) 0;
}

.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: stretch;
}

.clinic-info-card {
  background-color: var(--glass-bg);
  border: 2px solid var(--secondary);
  border-radius: var(--border-radius);
  padding: 3rem;
  box-shadow: var(--glass-shadow);
  display: flex;
  flex-direction: column;
}

.clinic-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 0.5rem;
}

.pulse-indicator-static {
  width: 10px;
  height: 10px;
  background-color: var(--secondary);
  border-radius: 50%;
  box-shadow: 0 0 0 4px var(--accent-light);
}

.clinic-brand h4 {
  font-size: 1.6rem;
  font-weight: 700;
}

.clinic-role {
  font-size: 0.95rem;
  color: var(--text-muted);
  margin-bottom: 2.5rem;
  font-weight: 500;
}

.info-block {
  margin-bottom: 2rem;
}

.info-block:last-of-type {
  margin-bottom: 3rem;
}

.info-label {
  display: block;
  font-size: 0.8rem;
  font-weight: 750;
  text-transform: uppercase;
  color: var(--secondary);
  letter-spacing: 0.05em;
  margin-bottom: 6px;
}

.info-val {
  font-size: 1.05rem;
  font-weight: 500;
}

.referral-card {
  background-color: var(--primary);
  color: var(--bg-white);
  border-radius: var(--border-radius);
  padding: 3rem;
  display: flex;
  flex-direction: column;
}

.referral-card h3 {
  color: var(--bg-white);
  font-size: 1.75rem;
  margin-bottom: 1.25rem;
}

.referral-card p {
  font-size: 1rem;
  opacity: 0.9;
  margin-bottom: 2rem;
}

.ref-details-list {
  margin-bottom: auto;
}

.ref-item {
  margin-bottom: 1.75rem;
}

.ref-item:last-child {
  margin-bottom: 0;
}

.ref-item strong {
  display: block;
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  opacity: 0.7;
  margin-bottom: 4px;
}

.ref-item span {
  font-size: 1.05rem;
}

.ref-link {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--accent);
}

.ref-link:hover {
  text-decoration: underline;
  color: var(--bg-white);
}

.physician-referral-note {
  margin-top: 3rem;
  padding: 1.25rem;
  background-color: rgba(255, 255, 255, 0.08);
  border-left: 4px solid var(--accent);
  border-radius: 4px;
}

.physician-referral-note p {
  font-size: 0.85rem;
  margin-bottom: 0;
  line-height: 1.5;
}

/* --- Footer --- */
.main-footer {
  background-color: var(--primary);
  color: var(--bg-white);
  padding: 4rem 0;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  gap: 2.5rem;
}

.footer-logo h4 {
  color: var(--bg-white);
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.footer-logo p {
  font-size: 0.85rem;
  opacity: 0.7;
}

.footer-links {
  display: flex;
  gap: 2rem;
}

.footer-links a {
  font-size: 0.9rem;
  opacity: 0.85;
}

.footer-links a:hover {
  opacity: 1;
  color: var(--accent);
}

.footer-copyright {
  font-size: 0.8rem;
  opacity: 0.5;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  width: 100%;
  padding-top: 2rem;
}

/* --- Navigation Responsive Menu --- */
@media (max-width: 991px) {
  /* Common spacing reduction */
  :root {
    --spacing-section: 4rem;
  }
  
  /* Hero structure */
  .hero-container {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 3.5rem;
  }
  
  .hero-title {
    font-size: 2.8rem;
  }
  
  .hero-subtitle {
    margin: 0 auto 2rem auto;
  }
  
  .hero-tag-container {
    justify-content: center;
  }
  
  .hero-actions {
    justify-content: center;
  }
  
  .hero-visual-content {
    justify-content: center;
  }

  /* About Grid */
  .about-grid {
    grid-template-columns: 1fr;
    gap: 3rem;
  }

  /* Specializations Grid */
  .interests-grid {
    grid-template-columns: 1fr;
    max-width: 600px;
    margin: 0 auto;
  }

  /* Timeline */
  .timeline-line {
    left: 20px;
  }

  .timeline-item {
    width: 100%;
    padding-left: 45px;
    padding-right: 0;
    text-align: left !important;
  }

  .timeline-item:nth-child(even) {
    left: 0;
  }

  .timeline-dot {
    left: 20px !important;
  }

  /* Publications */
  .publications-grid {
    grid-template-columns: 1fr;
  }

  /* Initiatives */
  .initiatives-grid {
    grid-template-columns: 1fr;
  }

  /* Contact */
  .contact-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  /* Interactive Mobile Navigation Drawer */
  .menu-toggle {
    display: block;
  }

  .menu-toggle .bar {
    display: block;
    width: 25px;
    height: 3px;
    margin: 5px auto;
    background-color: var(--primary);
    transition: all 0.3s ease-in-out;
  }

  .menu-toggle[aria-expanded="true"] .bar:nth-child(2) {
    opacity: 0;
  }

  .menu-toggle[aria-expanded="true"] .bar:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
  }

  .menu-toggle[aria-expanded="true"] .bar:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
  }

  .nav-menu {
    position: fixed;
    top: 75px;
    left: -100%;
    width: 100%;
    height: calc(100vh - 75px);
    background-color: var(--bg-white);
    border-top: 1px solid var(--border-light);
    display: block;
    padding: 3rem 2rem;
    transition: left 0.4s cubic-bezier(0.8, 0, 0.3, 1);
    box-shadow: 0 15px 30px rgba(0,0,0,0.05);
  }

  .nav-menu.open {
    left: 0;
  }

  .nav-list {
    flex-direction: column;
    align-items: flex-start;
    gap: 2rem;
  }

  .nav-link {
    font-size: 1.25rem;
    font-weight: 600;
  }

  .nav-btn {
    width: 100%;
    text-align: center;
    padding: 1rem;
  }
}