/* ===================================
   CSS Variables & Design System
   =================================== */
:root {
  /* Northwestern University Colors */
  --nu-purple: #4E2A84;
  --nu-purple-dark: #401F68;
  --nu-purple-light: #836EAA;
  --nu-purple-lighter: #B6ACD1;
  --accent-cyan: #00D1FF;
  --accent-teal: #00B5AD;

  /* Neutral Colors */
  --white: #FFFFFF;
  --off-white: #F9F9FB;
  --light-gray: #E8E8EC;
  --gray: #B0B0B8;
  --dark-gray: #4A4A4A;
  --black: #1A1A1A;

  /* Semantic Colors */
  --primary: var(--nu-purple);
  --primary-dark: var(--nu-purple-dark);
  --primary-light: var(--nu-purple-light);
  --secondary: var(--accent-cyan);
  --text-primary: var(--black);
  --text-secondary: var(--dark-gray);
  --text-light: var(--gray);
  --bg-primary: var(--white);
  --bg-secondary: var(--off-white);
  --bg-dark: var(--nu-purple);

  /* Typography */
  --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Source Sans Pro', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 4rem;
  --spacing-xl: 6rem;

  /* Borders & Shadows */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --shadow-sm: 0 2px 8px rgba(78, 42, 132, 0.08);
  --shadow-md: 0 4px 16px rgba(78, 42, 132, 0.12);
  --shadow-lg: 0 8px 32px rgba(78, 42, 132, 0.16);

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
  --transition-slow: 0.5s ease;
}

/* ===================================
   Reset & Base Styles
   =================================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-body);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  color: var(--primary-dark);
}

h1 {
  font-size: 3.5rem;
}

h2 {
  font-size: 2.5rem;
}

h3 {
  font-size: 2rem;
}

h4 {
  font-size: 1.5rem;
}

h5 {
  font-size: 1.25rem;
}

h6 {
  font-size: 1rem;
}

p {
  margin-bottom: 1rem;
  color: var(--text-secondary);
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--secondary);
}

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

/* ===================================
   Navigation
   =================================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-sm);
  z-index: 1000;
  transition: all var(--transition-normal);
}

.navbar.scrolled {
  box-shadow: var(--shadow-md);
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
  font-family: var(--font-heading);
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.nav-logo-img {
  height: 2rem;
  width: auto;
  object-fit: contain;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.nav-link {
  color: var(--text-primary);
  font-weight: 500;
  padding: 0.5rem 0;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--secondary);
  transition: width var(--transition-normal);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary);
}

.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--primary);
  cursor: pointer;
}

/* ===================================
   Hero Section
   =================================== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, var(--nu-purple) 0%, var(--nu-purple-dark) 100%);
  color: var(--white);
  padding: var(--spacing-xl) var(--spacing-md) var(--spacing-lg);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg width="100" height="100" xmlns="http://www.w3.org/2000/svg"><circle cx="50" cy="50" r="1" fill="rgba(255,255,255,0.1)"/></svg>');
  opacity: 0.3;
}

.hero-content {
  max-width: 1200px;
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
  position: relative;
  z-index: 1;
}

.hero-intro {
  display: flex;
  align-items: center;
  gap: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
}

.hero-text {
  flex: 1;
}

.hero-title {
  font-size: 4rem;
  color: var(--white);
  margin-bottom: var(--spacing-sm);
  animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
  font-size: 1.5rem;
  color: var(--nu-purple-lighter);
  margin-bottom: var(--spacing-md);
  animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-tagline {
  font-size: 1.25rem;
  color: rgba(255, 255, 255, 0.95);
  margin-bottom: var(--spacing-md);
  line-height: 1.6;
  animation: fadeInUp 0.8s ease 0.4s backwards;
}

.hero-buttons {
  display: flex;
  gap: 1rem;
  animation: fadeInUp 0.8s ease 0.6s backwards;
}

.hero-image {
  flex: 0 0 300px;
  animation: fadeInRight 0.8s ease 0.4s backwards;
}

.profile-photo {
  width: 300px;
  height: 300px;
  border-radius: 50%;
  object-fit: cover;
  border: 6px solid rgba(255, 255, 255, 0.2);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  user-select: none;
  -webkit-user-select: none;
  -moz-user-select: none;
  -ms-user-select: none;
  -webkit-user-drag: none;
  -khtml-user-drag: none;
  -moz-user-drag: none;
  -o-user-drag: none;
  user-drag: none;
}

/* Hero About Card */
.hero-about-card {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
  animation: fadeInUp 0.8s ease 0.8s backwards;
  border: 2px solid rgba(255, 255, 255, 0.3);
}

.about-card-content {
  max-width: 900px;
  margin: 0 auto;
}

.about-card-title {
  font-size: 2rem;
  color: var(--primary-dark);
  margin-bottom: var(--spacing-md);
  text-align: center;
  position: relative;
  display: inline-block;
  width: 100%;
}

.about-card-title::after {
  content: '';
  position: absolute;
  bottom: -8px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  border-radius: 2px;
}

.about-card-text {
  font-size: 1.125rem;
  line-height: 1.8;
  color: var(--text-secondary);
  margin-bottom: 1rem;
  text-align: center;
}

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

.about-card-text strong {
  color: var(--primary);
  font-weight: 600;
}

/* ===================================
   Buttons
   =================================== */
.btn {
  display: inline-block;
  padding: 0.875rem 2rem;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: 1rem;
  text-align: center;
  cursor: pointer;
  transition: all var(--transition-normal);
  border: 2px solid transparent;
}

.btn-primary {
  background: var(--secondary);
  color: var(--white);
  box-shadow: 0 4px 16px rgba(0, 209, 255, 0.3);
}

.btn-primary:hover {
  background: #00B8E6;
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(0, 209, 255, 0.4);
}

.btn-outline {
  background: transparent;
  color: var(--white);
  border-color: var(--white);
}

.btn-outline:hover {
  background: var(--white);
  color: var(--primary);
}

/* ===================================
   Section Styles
   =================================== */
.section {
  padding: var(--spacing-xl) var(--spacing-md);
  max-width: 1200px;
  margin: 0 auto;
}

.section-alt {
  background: var(--bg-secondary);
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-lg);
}

.section-title {
  font-size: 2.5rem;
  margin-bottom: var(--spacing-sm);
  position: relative;
  display: inline-block;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  border-radius: 2px;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-light);
  max-width: 600px;
  margin: 1.5rem auto 0;
}

/* ===================================
   Research Cards
   =================================== */
.research-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-md);
  margin-top: var(--spacing-md);
}

.research-card {
  background: var(--white);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
  border: 2px solid transparent;
}

.research-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--secondary);
}

.research-icon {
  width: 60px;
  height: 60px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  margin-bottom: var(--spacing-sm);
  color: var(--white);
}

.research-card h3 {
  margin-bottom: var(--spacing-sm);
  color: var(--primary);
}

.research-card p {
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ===================================
   Publications
   =================================== */
.publications-list {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.publication-item {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  border: 2px solid transparent;
  overflow: hidden;
  display: flex;
  flex-direction: row;
  align-items: center;
}

.publication-item:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
  border-color: var(--secondary);
}

.publication-image {
  flex-shrink: 0;
  width: 280px;
  height: 280px;
  background: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-md);
  overflow: hidden;
}

.publication-image img {
  max-width: 100%;
  max-height: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
  border-radius: var(--radius-sm);
}

.publication-content {
  flex: 1;
  padding: var(--spacing-md) var(--spacing-lg);
}

.publication-title {
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--primary-dark);
  margin-bottom: 0.75rem;
  line-height: 1.3;
}

.publication-authors {
  color: var(--text-secondary);
  margin-bottom: var(--spacing-sm);
  font-size: 0.95rem;
  line-height: 1.6;
}

.publication-authors .author-highlight {
  font-weight: 700;
  color: var(--primary);
}

.publication-meta {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: var(--spacing-sm);
}

.publication-venue {
  display: inline-block;
  background: var(--nu-purple-lighter);
  color: var(--primary-dark);
  padding: 0.375rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
}

.publication-status {
  display: inline-block;
  background: var(--secondary);
  color: var(--white);
  padding: 0.375rem 1rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
}

.publication-links {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: var(--spacing-sm);
}

.publication-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--primary);
  font-weight: 600;
  padding: 0.5rem 1rem;
  background: var(--off-white);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  font-size: 0.95rem;
}

.publication-link:hover {
  background: var(--primary);
  color: var(--white);
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(78, 42, 132, 0.2);
}

.publication-link i {
  font-size: 0.875rem;
}

/* ===================================
   Timeline
   =================================== */
.timeline {
  position: relative;
  max-width: 900px;
  margin: 0 auto;
  padding: var(--spacing-md) 0;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 3px;
  height: 100%;
  background: linear-gradient(180deg, var(--primary), var(--secondary));
}

.timeline-item {
  display: flex;
  margin-bottom: var(--spacing-lg);
  position: relative;
}

.timeline-item:nth-child(odd) {
  flex-direction: row-reverse;
}

.timeline-content {
  flex: 1;
  background: var(--white);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  margin: 0 var(--spacing-md);
  transition: all var(--transition-normal);
}

.timeline-content:hover {
  box-shadow: var(--shadow-md);
  transform: scale(1.02);
}

.timeline-marker {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  width: 20px;
  height: 20px;
  background: var(--secondary);
  border: 4px solid var(--white);
  border-radius: 50%;
  box-shadow: 0 0 0 4px var(--primary-light);
  z-index: 1;
}

.timeline-date {
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 0.5rem;
  font-size: 0.95rem;
}

.timeline-title {
  font-size: 1.25rem;
  margin-bottom: 0.5rem;
  color: var(--primary-dark);
}

.timeline-organization {
  color: var(--text-light);
  font-style: italic;
  margin-bottom: var(--spacing-sm);
}

.timeline-description {
  color: var(--text-secondary);
  line-height: 1.7;
}

.timeline-description ul {
  margin-top: 0.5rem;
  padding-left: 1.5rem;
}

.timeline-description li {
  margin-bottom: 0.5rem;
}

/* ===================================
   Service Section
   =================================== */
.service-list {
  max-width: 1000px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
}

.service-item {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
  border: 2px solid transparent;
  overflow: hidden;
  display: flex;
  flex-direction: row;
  align-items: flex-start;
  padding: var(--spacing-lg);
  gap: var(--spacing-md);
}

.service-item:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-4px);
  border-color: var(--secondary);
}

.service-icon {
  flex-shrink: 0;
  width: 80px;
  height: 80px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  color: var(--white);
  box-shadow: 0 4px 12px rgba(78, 42, 132, 0.2);
}

.service-content {
  flex: 1;
}

.service-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-dark);
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.service-organization {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: var(--spacing-sm);
  line-height: 1.4;
}

.service-description {
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: var(--spacing-md);
}

.service-meta {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
  margin-bottom: var(--spacing-md);
}

.service-date,
.service-location {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.service-date i,
.service-location i {
  color: var(--primary);
  font-size: 0.875rem;
}

.service-links {
  display: flex;
  gap: var(--spacing-md);
  flex-wrap: wrap;
}

.service-link {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--primary);
  font-weight: 600;
  padding: 0.5rem 1rem;
  background: var(--off-white);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
  font-size: 0.95rem;
}

.service-link:hover {
  background: var(--primary);
  color: var(--white);
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(78, 42, 132, 0.2);
}

.service-link i {
  font-size: 0.875rem;
}

/* ===================================
   Education Section
   =================================== */
.education-grid {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
  max-width: 1000px;
  margin: 0 auto;
}

.education-card {
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  overflow: hidden;
  transition: all var(--transition-normal);
  border: 2px solid transparent;
  display: flex;
  flex-direction: row;
  align-items: center;
}

.education-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: var(--secondary);
}

.education-logo {
  background: var(--white);
  padding: var(--spacing-md) var(--spacing-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  width: 220px;
}

.education-logo img {
  max-width: 150px;
  max-height: 140px;
  width: auto;
  height: auto;
  object-fit: contain;
}

.education-content {
  padding: var(--spacing-md) var(--spacing-lg);
  flex: 1;
}

.education-header {
  margin-bottom: var(--spacing-sm);
}

.education-date {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.5rem;
}

.education-degree {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-dark);
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.education-institution {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 0.25rem;
}

.education-location {
  font-size: 0.95rem;
  color: var(--text-light);
  margin-bottom: 0;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.education-location i {
  color: var(--text-light);
  font-size: 0.875rem;
}

.education-details {
  margin-top: var(--spacing-sm);
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-md);
}

.education-detail-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 1rem;
  padding: 0.5rem 1rem;
  background: var(--off-white);
  border-radius: var(--radius-sm);
}

.education-detail-item i {
  color: var(--primary);
  font-size: 1rem;
}

/* ===================================
   Honors & Awards Section
   =================================== */
.honors-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-md);
  max-width: 1100px;
  margin: 0 auto;
}

.honor-card {
  background: var(--white);
  padding: var(--spacing-md);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
  border: 2px solid transparent;
  text-align: center;
}

.honor-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg);
  border-color: var(--secondary);
}

.honor-icon {
  width: 70px;
  height: 70px;
  background: linear-gradient(135deg, var(--primary), var(--primary-light));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  margin: 0 auto var(--spacing-sm);
  color: var(--white);
  box-shadow: 0 4px 12px rgba(78, 42, 132, 0.2);
}

.honor-title {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--primary-dark);
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.honor-year {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--secondary);
  margin-bottom: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.honor-description {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin: 0;
}

/* ===================================
   News Section
   =================================== */
.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
  gap: var(--spacing-md);
}

.news-card {
  background: var(--white);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-normal);
}

.news-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.news-date {
  background: var(--primary);
  color: var(--white);
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
  font-weight: 600;
}

.news-content {
  padding: var(--spacing-md);
}

.news-title {
  font-size: 1.25rem;
  margin-bottom: var(--spacing-sm);
  color: var(--primary-dark);
}

.news-description {
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ===================================
   Contact Section
   =================================== */
.contact-container {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.contact-info {
  display: flex;
  justify-content: center;
  gap: var(--spacing-lg);
  margin: var(--spacing-md) 0;
  flex-wrap: wrap;
}

.contact-item {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--text-secondary);
  font-size: 1.125rem;
}

.contact-item i {
  color: var(--primary);
  font-size: 1.5rem;
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-top: var(--spacing-md);
}

.social-link {
  width: 50px;
  height: 50px;
  background: var(--primary);
  color: var(--white);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  transition: all var(--transition-normal);
}

.social-link:hover {
  background: var(--secondary);
  transform: translateY(-4px);
  box-shadow: 0 8px 16px rgba(0, 209, 255, 0.3);
}

/* ===================================
   Footer
   =================================== */
.footer {
  background: var(--primary-dark);
  color: var(--white);
  text-align: center;
  padding: var(--spacing-md);
}

.footer p {
  color: rgba(255, 255, 255, 0.8);
  margin: 0;
}

/* ===================================
   Animations
   =================================== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }

  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.fade-in {
  opacity: 0;
  animation: fadeInUp 0.6s ease forwards;
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 968px) {
  .timeline::before {
    left: 30px;
  }

  .timeline-item,
  .timeline-item:nth-child(odd) {
    flex-direction: row;
  }

  .timeline-marker {
    left: 30px;
  }

  .timeline-content {
    margin-left: 70px;
    margin-right: 0;
  }

  .education-card {
    flex-direction: column;
  }

  .education-logo {
    width: 100%;
    padding: var(--spacing-md);
  }

  .education-logo img {
    max-width: 180px;
  }

  .honors-grid {
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  }
}

@media (max-width: 768px) {
  html {
    font-size: 14px;
  }

  h1 {
    font-size: 2.5rem;
  }

  h2 {
    font-size: 2rem;
  }

  .nav-menu {
    position: fixed;
    top: 70px;
    left: -100%;
    flex-direction: column;
    background: var(--white);
    width: 100%;
    padding: 2rem;
    box-shadow: var(--shadow-md);
    transition: left var(--transition-normal);
    gap: 1rem;
  }

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

  .mobile-menu-toggle {
    display: block;
  }

  .hero-intro {
    flex-direction: column-reverse;
    text-align: center;
  }

  .hero-title {
    font-size: 2.5rem;
  }

  .hero-subtitle {
    font-size: 1.25rem;
  }

  .hero-tagline {
    font-size: 1.125rem;
  }

  .hero-image {
    flex: 0 0 200px;
  }

  .profile-photo {
    width: 200px;
    height: 200px;
    user-select: none;
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    -webkit-user-drag: none;
    -khtml-user-drag: none;
    -moz-user-drag: none;
    -o-user-drag: none;
    user-drag: none;
  }

  .hero-buttons {
    justify-content: center;
    flex-wrap: wrap;
  }

  .hero-about-card {
    padding: var(--spacing-md);
  }

  .about-card-title {
    font-size: 1.75rem;
  }

  .about-card-text {
    font-size: 1rem;
    text-align: left;
  }

  .research-grid {
    grid-template-columns: 1fr;
  }

  .publication-item {
    flex-direction: column;
  }

  .publication-image {
    width: 100%;
    height: 240px;
  }

  .publication-content {
    padding: var(--spacing-md);
  }

  .service-item {
    flex-direction: column;
    padding: var(--spacing-md);
  }

  .service-icon {
    width: 70px;
    height: 70px;
    font-size: 1.75rem;
  }

  .service-links {
    flex-direction: column;
  }

  .service-link {
    width: 100%;
    justify-content: center;
  }

  .education-card {
    flex-direction: column;
  }

  .education-logo {
    width: 100%;
  }

  .honors-grid {
    grid-template-columns: 1fr;
  }

  .news-grid {
    grid-template-columns: 1fr;
  }

  .contact-info {
    flex-direction: column;
    gap: var(--spacing-sm);
  }

  .section {
    padding: var(--spacing-lg) var(--spacing-sm);
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }

  .hero-tagline {
    font-size: 1rem;
  }

  .about-card-title {
    font-size: 1.5rem;
  }

  .section-title {
    font-size: 2rem;
  }

  .btn {
    padding: 0.75rem 1.5rem;
    font-size: 0.95rem;
  }
}