/* Add custom styles here */
.header-nav {
    background-color: #f8f9fa;
}
.navbar-brand {
    font-weight: bold;
}

/* Modern Research Lab Website Styles */

/* Global Styles */
:root {
  --primary-color: #3498db;
  --secondary-color: #2c3e50;
  --accent-color: #e74c3c;
  --light-bg: #f8f9fa;
  --dark-bg: #2c3e50;
  --text-dark: #333333;
  --text-light: #ffffff;
  --text-muted: #6c757d;
  --section-padding: 4rem 0;
  --transition-speed: 0.3s;
}

body {
  font-family: 'Inter', 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  color: var(--text-dark);
  line-height: 1.6;
  background-color: #ffffff;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--secondary-color);
}

.display-4 {
  font-weight: 800;
  letter-spacing: -0.5px;
}

p {
  margin-bottom: 1.5rem;
}

.lead {
  font-size: 1.25rem;
  font-weight: 400;
}

/* Navigation */
.header-nav {
  background-color: #ffffff;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  padding: 1rem 0;
  position: sticky;
  top: 0;
  z-index: 1000;
  transition: all var(--transition-speed) ease;
}

.navbar-brand {
  font-weight: 800;
  font-size: 1.5rem;
  color: var(--primary-color);
  letter-spacing: -0.5px;
}

.navbar-nav .nav-link {
  font-weight: 600;
  color: var(--secondary-color);
  padding: 0.5rem 1rem;
  margin: 0 0.25rem;
  border-radius: 4px;
  transition: all var(--transition-speed) ease;
}

.navbar-nav .nav-link:hover,
.navbar-nav .nav-link.active {
  color: var(--primary-color);
  background-color: rgba(52, 152, 219, 0.1);
}

/* Sections */
main {
  padding-top: 2rem;
  padding-bottom: 4rem;
}

section {
  padding: var(--section-padding);
}

.section-heading {
  position: relative;
  margin-bottom: 2.5rem;
  padding-bottom: 1rem;
}

.section-heading:after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 4px;
  background-color: var(--primary-color);
}

/* Hero Section */
.hero-section {
  padding: 5rem 0;
  background: linear-gradient(135deg, var(--light-bg) 0%, #ffffff 100%);
}

/* News Section */
.news-section h3 {
  font-size: 1.75rem;
  position: relative;
  padding-bottom: 0.75rem;
  margin-bottom: 1.5rem;
}

.news-section h3:after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 50px;
  height: 3px;
  background-color: var(--primary-color);
}

.news-section ul {
  padding-left: 1.25rem;
}

.news-section li {
  margin-bottom: 1rem;
  position: relative;
}

/* Links Section */
.useful-links ul {
  list-style-type: none;
  padding-left: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.useful-links li {
  margin-bottom: 0.75rem;
}

.useful-links a {
  display: inline-flex;
  align-items: center;
  padding: 0.5rem 1rem;
  background-color: var(--light-bg);
  color: var(--secondary-color);
  text-decoration: none;
  border-radius: 4px;
  font-weight: 600;
  transition: all var(--transition-speed) ease;
}

.useful-links a:hover {
  background-color: var(--primary-color);
  color: var(--text-light);
  transform: translateY(-2px);
}

/* Card Styles */
.card {
  border: none;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  transition: all var(--transition-speed) ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

/* Button Styles */
.btn {
  font-weight: 600;
  padding: 0.5rem 1.5rem;
  border-radius: 4px;
  transition: all var(--transition-speed) ease;
}

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

.btn-primary:hover {
  background-color: #2980b9;
  border-color: #2980b9;
  transform: translateY(-2px);
}

/* Footer */
footer {
  background-color: var(--light-bg);
  color: var(--text-dark);
  padding: 3rem 0;
  margin-top: 2rem;
}

footer h5 {
  font-weight: 700;
  color: var(--primary-color);
  margin-bottom: 1.25rem;
}

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

footer .social-icons {
  display: flex;
  gap: 1.25rem;
}

footer .social-icon-link {
  transition: transform 0.3s ease;
  display: inline-block;
}

footer .social-icon-link:hover {
  transform: translateY(-3px);
}

footer .social-icon-link i {
  font-size: 1.75rem;
}

footer .fa-github {
  color: #333333;
}

footer .fa-youtube {
  color: #FF0000;
}

footer .fa-instagram {
  color: #E1306C;
}

footer hr {
  border-color: rgba(0, 0, 0, 0.1);
  margin: 2rem 0;
}

footer .quick-links a {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.3s ease;
  display: block;
  margin-bottom: 0.75rem;
}

footer .quick-links a:hover {
  color: var(--primary-color);
}

footer .copyright {
  color: var(--text-muted);
  text-align: center;
  font-size: 0.9rem;
}

/* Helper Classes */
.text-gradient {
  background: linear-gradient(90deg, var(--primary-color), #9b59b6);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  color: transparent;
}

/* Responsive Adjustments */
@media (max-width: 768px) {
  .header-nav {
    padding: 0.75rem 0;
  }
  
  .navbar-brand {
    font-size: 1.25rem;
  }
  
  .display-4 {
    font-size: 2rem;
  }
  
  .section-heading {
    margin-bottom: 1.5rem;
  }
  
  .hero-section {
    padding: 3rem 0;
  }
}