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

body {
  font-family: "Poppins", sans-serif;
  line-height: 1.6;
  color: #333333;
  background-color: #ffffff;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* Color Variables */
:root {
  --primary-pink: #e91e63;
  --light-pink: #f8bbd0;
  --white: #ffffff;
  --light-grey: #f5f5f5;
  --dark-grey: #333333;
  --charcoal: #444444;
  --teal: #009688;
  --soft-aqua: #80cbc4;
  --lavender: #ba68c8;
  --soft-purple: #e1bee7;
  --shadow: rgba(0, 0, 0, 0.1);
  --gradient-pink: linear-gradient(135deg, #e91e63, #f8bbd0);
  --gradient-teal: linear-gradient(135deg, #009688, #80cbc4);
}

/* Navigation */
.navbar {
  background: var(--white);
  box-shadow: 0 2px 10px var(--shadow);
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 1000;
  transition: all 0.3s ease;
}

.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

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

.nav-logo i {
  margin-right: 10px;
  font-size: 1.8rem;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 30px;
}

.nav-link {
  text-decoration: none;
  color: var(--dark-grey);
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
}

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

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--primary-pink);
}

.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
}

.bar {
  width: 25px;
  height: 3px;
  background: var(--dark-grey);
  margin: 3px 0;
  transition: 0.3s;
}

/* Hero Section */
.hero {
  background: var(--gradient-pink);
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 70px;
  position: relative;
  overflow: hidden;
}

.hero-content {
  flex: 1;
  color: var(--white);
  z-index: 2;
}

.hero-title {
  font-size: 3.5rem;
  font-weight: 700;
  margin-bottom: 20px;
  animation: fadeInUp 1s ease;
}

.hero-subtitle {
  font-size: 1.2rem;
  margin-bottom: 30px;
  opacity: 0.9;
  animation: fadeInUp 1s ease 0.2s both;
}

.hero-buttons {
  display: flex;
  gap: 20px;
  animation: fadeInUp 1s ease 0.4s both;
}

.hero-image {
  flex: 1;
  display: flex;
  justify-content: center;
  align-items: center;
}

.ribbon-animation {
  font-size: 8rem;
  color: var(--white);
  opacity: 0.8;
  animation: float 3s ease-in-out infinite;
}

/* Buttons */
.btn {
  padding: 12px 30px;
  border: none;
  border-radius: 50px;
  font-weight: 600;
  text-decoration: none;
  display: inline-block;
  transition: all 0.3s ease;
  cursor: pointer;
  font-size: 1rem;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 5px 15px rgba(233, 30, 99, 0.3);
}

.btn-secondary {
  background: transparent;
  color: var(--white);
  border: 2px solid var(--white);
}

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

.btn-outline {
  background: transparent;
  color: var(--primary-pink);
  border: 2px solid var(--primary-pink);
}

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

/* Statistics Section */
.stats {
  padding: 80px 0;
  background: var(--white);
}

.section-title {
  text-align: center;
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 50px;
  color: var(--dark-grey);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
}

.stat-card {
  text-align: center;
  padding: 40px 20px;
  background: var(--white);
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
  transition: transform 0.3s ease;
}

.stat-card:hover {
  transform: translateY(-5px);
}

.stat-number {
  font-size: 3rem;
  font-weight: 700;
  color: var(--primary-pink);
  margin-bottom: 10px;
}

.stat-label {
  font-size: 1.1rem;
  color: var(--charcoal);
  font-weight: 500;
}

/* About Section */
.about {
  padding: 80px 0;
  background: var(--light-grey);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px;
  align-items: center;
}

.about-text h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--dark-grey);
}

.about-text p {
  font-size: 1.1rem;
  margin-bottom: 20px;
  text-align: justify;
  color: var(--charcoal);
}

.awareness-ribbon {
  font-size: 6rem;
  color: var(--primary-pink);
  text-align: center;
  animation: pulse 2s ease-in-out infinite;
}

/* Quick Links */
.quick-links {
  padding: 80px 0;
  background: var(--white);
}

.links-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
}

.link-card {
  text-decoration: none;
  color: inherit;
  padding: 40px 30px;
  background: var(--white);
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
  transition: all 0.3s ease;
  text-align: center;
}

.link-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(233, 30, 99, 0.2);
}

.link-card i {
  font-size: 3rem;
  color: var(--primary-pink);
  margin-bottom: 20px;
}

.link-card h3 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 15px;
  color: var(--dark-grey);
}

.link-card p {
  color: var(--charcoal);
  line-height: 1.6;
}

/* Page Headers */
.page-header {
  background: var(--gradient-teal);
  padding: 120px 0 80px;
  text-align: center;
  color: var(--white);
}

.page-header h1 {
  font-size: 3rem;
  font-weight: 700;
  margin-bottom: 20px;
}

.page-header p {
  font-size: 1.2rem;
  opacity: 0.9;
}

/* Diagnostic Methods */
.diagnostic-section {
  padding: 80px 0;
}

.methods-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 30px;
}

.method-card {
  background: var(--white);
  padding: 40px 30px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
  transition: transform 0.3s ease;
}

.method-card:hover {
  transform: translateY(-5px);
}

.method-icon {
  font-size: 3rem;
  color: var(--teal);
  margin-bottom: 20px;
  text-align: center;
}

.method-card h3 {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 15px;
  color: var(--dark-grey);
}

.method-card p {
  color: var(--charcoal);
  margin-bottom: 20px;
}

.method-details h4 {
  color: var(--primary-pink);
  margin-bottom: 10px;
  font-weight: 600;
}

.method-details ul {
  list-style: none;
  padding-left: 0;
}

.method-details li {
  padding: 5px 0;
  color: var(--charcoal);
  position: relative;
  padding-left: 20px;
}

.method-details li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--teal);
  font-weight: bold;
}

/* Timeline */
.biopsy-timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.timeline-item {
  display: flex;
  align-items: center;
  margin-bottom: 40px;
  position: relative;
}

.timeline-icon {
  background: var(--teal);
  color: var(--white);
  width: 60px;
  height: 60px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-right: 30px;
  flex-shrink: 0;
}

.timeline-content {
  background: var(--white);
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
  flex: 1;
}

.timeline-content h3 {
  color: var(--dark-grey);
  margin-bottom: 10px;
  font-weight: 600;
}

.procedure-details {
  display: flex;
  gap: 20px;
  margin-top: 15px;
}

.procedure-details span {
  display: flex;
  align-items: center;
  gap: 5px;
  color: var(--charcoal);
  font-size: 0.9rem;
}

/* Quiz Section */
.quiz-section {
  padding: 80px 0;
}

.quiz-container {
  max-width: 600px;
  margin: 0 auto;
  background: var(--white);
  padding: 40px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
}

.quiz-question h3 {
  color: var(--primary-pink);
  margin-bottom: 20px;
}

.quiz-options {
  display: grid;
  gap: 15px;
  margin-top: 20px;
}

.quiz-option {
  padding: 15px 20px;
  border: 2px solid var(--light-grey);
  background: var(--white);
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.3s ease;
  font-size: 1rem;
}

.quiz-option:hover {
  border-color: var(--primary-pink);
  background: var(--light-pink);
}

.quiz-option.correct {
  background: var(--teal);
  color: var(--white);
  border-color: var(--teal);
}

.quiz-option.incorrect {
  background: var(--primary-pink);
  color: var(--white);
  border-color: var(--primary-pink);
}

.quiz-result {
  text-align: center;
}

.quiz-result h3 {
  color: var(--primary-pink);
  margin-bottom: 20px;
}

/* Treatment Sections */
.treatment-overview {
  padding: 80px 0;
  background: var(--light-grey);
}

.overview-content {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.overview-content h2 {
  font-size: 2.5rem;
  font-weight: 700;
  margin-bottom: 20px;
  color: var(--dark-grey);
}

.treatment-factors {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 20px;
  margin-top: 40px;
}

.factor {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 20px;
  background: var(--white);
  border-radius: 10px;
  box-shadow: 0 3px 10px var(--shadow);
}

.factor i {
  font-size: 2rem;
  color: var(--primary-pink);
}

.treatment-section {
  padding: 80px 0;
}

.treatment-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 30px;
}

.treatment-card {
  background: var(--white);
  padding: 40px 30px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
  transition: transform 0.3s ease;
}

.treatment-card:hover {
  transform: translateY(-5px);
}

.treatment-icon {
  font-size: 3rem;
  color: var(--teal);
  margin-bottom: 20px;
  text-align: center;
}

.success-rate {
  margin-top: 20px;
  padding: 15px;
  background: var(--light-grey);
  border-radius: 10px;
  text-align: center;
}

.rate-label {
  font-weight: 600;
  color: var(--dark-grey);
}

.rate-value {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--primary-pink);
  margin-left: 10px;
}

/* Radiation Timeline */
.radiation-timeline {
  max-width: 800px;
  margin: 0 auto;
}

.treatment-schedule {
  display: flex;
  gap: 20px;
  margin-top: 15px;
}

.treatment-schedule span {
  display: flex;
  align-items: center;
  gap: 5px;
  color: var(--charcoal);
  font-size: 0.9rem;
}

/* Chemotherapy Grid */
.chemo-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 30px;
}

.chemo-card {
  background: var(--white);
  padding: 40px 30px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
}

.chemo-card h3 {
  color: var(--dark-grey);
  margin-bottom: 15px;
  font-weight: 600;
}

.chemo-types,
.targeted-therapies {
  display: grid;
  gap: 15px;
  margin-top: 20px;
}

.chemo-type,
.therapy {
  padding: 15px;
  background: var(--light-grey);
  border-radius: 10px;
}

.chemo-type h4,
.therapy h4 {
  color: var(--primary-pink);
  margin-bottom: 5px;
  font-weight: 600;
}

/* Hormone Treatments */
.hormone-treatments {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}

.hormone-card {
  background: var(--white);
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
  text-align: center;
}

.hormone-icon {
  font-size: 2.5rem;
  color: var(--lavender);
  margin-bottom: 20px;
}

.hormone-card h3 {
  color: var(--dark-grey);
  margin-bottom: 15px;
  font-weight: 600;
}

.hormone-card ul {
  list-style: none;
  padding: 0;
  text-align: left;
}

.hormone-card li {
  padding: 8px 0;
  color: var(--charcoal);
  border-bottom: 1px solid var(--light-grey);
}

/* Comparison Tool */
.comparison-section {
  padding: 80px 0;
}

.comparison-tool {
  max-width: 800px;
  margin: 0 auto;
  background: var(--white);
  padding: 40px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
}

.comparison-filters {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 30px;
}

.filter-select {
  padding: 12px;
  border: 2px solid var(--light-grey);
  border-radius: 8px;
  font-size: 1rem;
  background: var(--white);
}

.comparison-results {
  text-align: center;
  color: var(--charcoal);
}

/* Case Analysis */
.case-overview {
  padding: 80px 0;
  background: var(--light-grey);
}

.overview-content {
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.case-stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 30px;
  margin-top: 40px;
}

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

.case-studies {
  padding: 80px 0;
}

.case-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 30px;
}

.case-card {
  background: var(--white);
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
  overflow: hidden;
  transition: transform 0.3s ease;
}

.case-card:hover {
  transform: translateY(-5px);
}

.case-header {
  background: var(--gradient-teal);
  color: var(--white);
  padding: 30px;
  position: relative;
}

.case-header h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 10px;
}

.case-tag {
  position: absolute;
  top: 20px;
  right: 20px;
  padding: 5px 15px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 600;
}

.case-tag.success {
  background: var(--teal);
  color: var(--white);
}

.case-tag.complex {
  background: var(--primary-pink);
  color: var(--white);
}

.case-tag.genetic {
  background: var(--lavender);
  color: var(--white);
}

.case-details {
  padding: 30px;
}

.patient-info {
  margin-bottom: 20px;
}

.patient-info p {
  margin-bottom: 5px;
  color: var(--charcoal);
}

.case-summary h4 {
  color: var(--primary-pink);
  margin: 15px 0 10px 0;
  font-weight: 600;
}

.case-summary ul {
  list-style: none;
  padding-left: 0;
  margin-bottom: 15px;
}

.case-summary li {
  padding: 5px 0;
  color: var(--charcoal);
  position: relative;
  padding-left: 20px;
}

.case-summary li::before {
  content: "•";
  position: absolute;
  left: 0;
  color: var(--teal);
  font-weight: bold;
}

.case-expand {
  margin: 0 30px 30px 30px;
  width: calc(100% - 60px);
}

/* Data Visualization */
.data-visualization {
  padding: 80px 0;
}

.chart-container {
  max-width: 1000px;
  margin: 0 auto;
  background: var(--white);
  padding: 40px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
}

.chart-controls {
  display: flex;
  gap: 15px;
  margin-bottom: 30px;
  flex-wrap: wrap;
}

.chart-btn {
  padding: 10px 20px;
  border: 2px solid var(--light-grey);
  background: var(--white);
  border-radius: 25px;
  cursor: pointer;
  transition: all 0.3s ease;
  font-weight: 500;
}

.chart-btn.active,
.chart-btn:hover {
  background: var(--primary-pink);
  color: var(--white);
  border-color: var(--primary-pink);
}

.chart-area {
  text-align: center;
  margin: 30px 0;
}

.chart-legend {
  text-align: center;
  color: var(--charcoal);
}

/* Outcome Analysis */
.outcome-analysis {
  padding: 80px 0;
}

.outcome-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 30px;
}

.outcome-card {
  background: var(--white);
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
}

.outcome-card h3 {
  color: var(--dark-grey);
  margin-bottom: 20px;
  font-weight: 600;
  text-align: center;
}

.outcome-stats {
  display: grid;
  gap: 20px;
}

.outcome-stat {
  display: grid;
  gap: 10px;
}

.stat-label {
  font-weight: 500;
  color: var(--charcoal);
}

.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--light-grey);
  border-radius: 4px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  background: var(--gradient-pink);
  border-radius: 4px;
  transition: width 1s ease;
}

.stat-value {
  font-weight: 700;
  color: var(--primary-pink);
  text-align: right;
}

/* Case Search */
.case-search {
  padding: 80px 0;
}

.search-tool {
  max-width: 800px;
  margin: 0 auto;
  background: var(--white);
  padding: 40px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
}

.search-filters {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  margin-bottom: 30px;
}

.search-results {
  text-align: center;
  color: var(--charcoal);
}

/* Case Submission */
.case-submission {
  padding: 80px 0;
}

.submission-form {
  max-width: 800px;
  margin: 0 auto;
  background: var(--white);
  padding: 40px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
}

.form-group {
  margin-bottom: 20px;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 600;
  color: var(--dark-grey);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 12px;
  border: 2px solid var(--light-grey);
  border-radius: 8px;
  font-size: 1rem;
  transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-pink);
}

/* Research Categories */
.research-categories {
  padding: 80px 0;
}

.category-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}

.category-card {
  background: var(--white);
  padding: 40px 30px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
  text-align: center;
  transition: transform 0.3s ease;
}

.category-card:hover {
  transform: translateY(-5px);
}

.category-icon {
  font-size: 3rem;
  color: var(--teal);
  margin-bottom: 20px;
}

.category-card h3 {
  color: var(--dark-grey);
  margin-bottom: 15px;
  font-weight: 600;
}

.category-card p {
  color: var(--charcoal);
  margin-bottom: 20px;
}

.paper-count {
  background: var(--light-pink);
  color: var(--primary-pink);
  padding: 8px 16px;
  border-radius: 20px;
  font-weight: 600;
  font-size: 0.9rem;
}

/* Featured Papers */
.featured-papers {
  padding: 80px 0;
}

.papers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: 30px;
}

.paper-card {
  background: var(--white);
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
  transition: transform 0.3s ease;
}

.paper-card:hover {
  transform: translateY(-5px);
}

.paper-card.featured {
  border: 3px solid var(--primary-pink);
}

.paper-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 20px;
}

.paper-header h3 {
  color: var(--dark-grey);
  font-weight: 600;
  flex: 1;
  margin-right: 20px;
}

.paper-year {
  background: var(--teal);
  color: var(--white);
  padding: 5px 12px;
  border-radius: 15px;
  font-size: 0.8rem;
  font-weight: 600;
}

.paper-authors {
  margin-bottom: 20px;
}

.paper-authors p {
  color: var(--charcoal);
  margin-bottom: 5px;
  font-size: 0.9rem;
}

.paper-abstract h4 {
  color: var(--primary-pink);
  margin-bottom: 10px;
  font-weight: 600;
}

.paper-abstract p {
  color: var(--charcoal);
  line-height: 1.6;
  margin-bottom: 20px;
}

.paper-metrics {
  display: flex;
  gap: 20px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}

.metric {
  display: flex;
  align-items: center;
  gap: 5px;
  color: var(--charcoal);
  font-size: 0.9rem;
}

.paper-actions {
  display: flex;
  gap: 15px;
  flex-wrap: wrap;
}

/* Research Database */
.research-database {
  padding: 80px 0;
}

.database-tools {
  margin-bottom: 40px;
}

.search-filters {
  display: grid;
  grid-template-columns: 1fr repeat(auto-fit, minmax(150px, 1fr));
  gap: 15px;
  align-items: end;
}

.search-input {
  padding: 12px;
  border: 2px solid var(--light-grey);
  border-radius: 8px;
  font-size: 1rem;
}

.papers-results {
  background: var(--white);
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
}

.results-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 20px;
  padding-bottom: 15px;
  border-bottom: 2px solid var(--light-grey);
}

.results-count {
  color: var(--charcoal);
  font-size: 0.9rem;
}

.pagination {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-top: 30px;
}

.page-btn {
  padding: 8px 12px;
  border: 2px solid var(--light-grey);
  background: var(--white);
  border-radius: 5px;
  cursor: pointer;
  transition: all 0.3s ease;
}

.page-btn:hover,
.page-btn.active {
  background: var(--primary-pink);
  color: var(--white);
  border-color: var(--primary-pink);
}

.page-dots {
  padding: 8px 12px;
  color: var(--charcoal);
}

/* References Section */
.references-section {
  padding: 80px 0;
}

.references-content {
  max-width: 1000px;
  margin: 0 auto;
}

.references-intro {
  text-align: center;
  margin-bottom: 40px;
  color: var(--charcoal);
}

.references-categories {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 40px;
}

.ref-category h3 {
  color: var(--primary-pink);
  margin-bottom: 20px;
  font-weight: 600;
}

.reference-list {
  list-style: decimal;
  padding-left: 20px;
}

.reference-list li {
  margin-bottom: 15px;
  color: var(--charcoal);
  line-height: 1.6;
}

.reference-list em {
  color: var(--teal);
  font-style: italic;
}

/* Collaboration Section */
.collaboration-section {
  padding: 80px 0;
}

.collaboration-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 50px;
  align-items: start;
}

.collaboration-info h3 {
  color: var(--dark-grey);
  margin-bottom: 20px;
  font-weight: 600;
}

.collaboration-info p {
  color: var(--charcoal);
  margin-bottom: 30px;
  line-height: 1.6;
}

.collaboration-benefits {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: 20px;
}

.benefit {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  text-align: center;
}

.benefit i {
  font-size: 2rem;
  color: var(--teal);
}

.benefit span {
  font-weight: 500;
  color: var(--charcoal);
}

.collaboration-form {
  background: var(--white);
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 5px 20px var(--shadow);
}

/* Footer */
.footer {
  background: var(--dark-grey);
  color: var(--white);
  padding: 60px 0 20px;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}

.footer-section h3 {
  color: var(--light-pink);
  margin-bottom: 20px;
  font-weight: 600;
}

.footer-section p {
  color: #cccccc;
  line-height: 1.6;
  margin-bottom: 10px;
}

.footer-section ul {
  list-style: none;
}

.footer-section ul li {
  margin-bottom: 10px;
}

.footer-section ul li a {
  color: #cccccc;
  text-decoration: none;
  transition: color 0.3s ease;
}

.footer-section ul li a:hover {
  color: var(--light-pink);
}

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid #444444;
  color: #cccccc;
}

/* Background Utilities */
.bg-light {
  background: var(--light-grey);
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0px);
  }
  50% {
    transform: translateY(-20px);
  }
}

@keyframes pulse {
  0%,
  100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
}

/* Responsive Design */
@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    left: -100%;
    top: 70px;
    flex-direction: column;
    background-color: var(--white);
    width: 100%;
    text-align: center;
    transition: 0.3s;
    box-shadow: 0 10px 27px var(--shadow);
    padding: 20px 0;
  }

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

  .hamburger {
    display: flex;
  }

  .hamburger.active .bar:nth-child(2) {
    opacity: 0;
  }

  .hamburger.active .bar:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
  }

  .hamburger.active .bar:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
  }

  .hero {
    flex-direction: column;
    text-align: center;
    padding: 100px 20px 60px;
  }

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

  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }

  .about-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .collaboration-content {
    grid-template-columns: 1fr;
  }

  .search-filters {
    grid-template-columns: 1fr;
  }

  .comparison-filters {
    grid-template-columns: 1fr;
  }

  .chart-controls {
    justify-content: center;
  }

  .paper-header {
    flex-direction: column;
    gap: 10px;
  }

  .paper-metrics {
    justify-content: center;
  }

  .paper-actions {
    justify-content: center;
  }

  .results-header {
    flex-direction: column;
    gap: 10px;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 15px;
  }

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

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

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

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

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

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

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

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

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