/* style.css - Main styles using design system */

/* Base styles already in variables.css */

/* Button Styles */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-base);
  font-weight: var(--font-medium);
  text-decoration: none;
  border: none;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: var(--transition-colors), transform var(--transition-fast);
  white-space: nowrap;
}

.btn:hover {
  transform: translateY(-1px);
}

.btn-primary {
  background: var(--gradient-primary);
  color: white;
  box-shadow: var(--shadow-md);
}

.btn-primary:hover {
  box-shadow: var(--shadow-lg);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.1);
  color: white;
  border: 2px solid rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(10px);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.2);
  color: white;
  border-color: rgba(255, 255, 255, 0.5);
  transform: translateY(-2px);
}

/* Variant for secondary button outside hero */
.btn-secondary.btn-outline {
  background: transparent;
  color: var(--primary-600);
  border: 2px solid var(--primary-600);
  backdrop-filter: none;
}

.btn-secondary.btn-outline:hover {
  background: var(--primary-600);
  color: white;
  border-color: var(--primary-600);
}

/* Hero Section */
.hero {
  background: var(--gradient-hero);
  color: white;
  padding: var(--space-20) 0 var(--space-16);
  overflow: hidden;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grain" width="100" height="100" patternUnits="userSpaceOnUse"><circle cx="25" cy="25" r="1" fill="white" opacity="0.1"/><circle cx="75" cy="75" r="1" fill="white" opacity="0.1"/><circle cx="50" cy="10" r="0.5" fill="white" opacity="0.1"/></pattern></defs><rect width="100" height="100" fill="url(%23grain)"/></svg>');
  pointer-events: none;
}

.hero-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-12);
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-title {
  font-size: var(--text-5xl);
  font-weight: var(--font-bold);
  line-height: 1.1;
  margin: 0 0 var(--space-6);
}

.hero-title .highlight {
  background: linear-gradient(135deg, var(--secondary-300), var(--secondary-100));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-description {
  font-size: var(--text-xl);
  opacity: 0.9;
  margin: 0 0 var(--space-8);
  line-height: 1.6;
}

.hero-buttons {
  display: flex;
  gap: var(--space-4);
  margin-bottom: var(--space-12);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}

.stat {
  text-align: center;
  padding: var(--space-4);
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-xl);
  backdrop-filter: blur(10px);
}

.stat i {
  font-size: var(--text-2xl);
  margin-bottom: var(--space-2);
  display: block;
}

.stat-number {
  display: block;
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
}

.stat-label {
  font-size: var(--text-sm);
  opacity: 0.8;
}

/* Sections */
.main {
  background: var(--gray-50);
}

section {
  padding: var(--space-20) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-16);
}

.section-header h2 {
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  color: var(--gray-900);
  margin: 0 0 var(--space-4);
}

.section-header p {
  font-size: var(--text-xl);
  color: var(--gray-600);
  margin: 0;
}

/* About Section */
.about {
  background: white;
}

.about-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-8);
}

.about-card {
  background: white;
  padding: var(--space-8);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-lg);
  text-align: center;
  transition: var(--transition-base);
  border: 1px solid var(--gray-100);
}

.about-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-2xl);
}

.card-icon {
  width: 80px;
  height: 80px;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-6);
}

.card-icon i {
  font-size: var(--text-3xl);
  color: white;
}

.about-card h3 {
  font-size: var(--text-xl);
  font-weight: var(--font-semibold);
  color: var(--gray-900);
  margin: 0 0 var(--space-4);
}

.about-card p {
  color: var(--gray-600);
  line-height: 1.6;
  margin: 0;
}

/* Publications Section */
.publications {
  background: var(--gray-100);
}

.publications-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: var(--space-8);
}

.publication-card {
  background: white;
  padding: var(--space-8);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-md);
  transition: var(--transition-base);
  border-left: 4px solid var(--primary-500);
}

.publication-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
}

.publication-icon {
  width: 60px;
  height: 60px;
  background: var(--primary-100);
  border-radius: var(--radius-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-4);
}

.publication-icon i {
  font-size: var(--text-2xl);
  color: var(--primary-600);
}

.publication-card h3 {
  font-size: var(--text-lg);
  font-weight: var(--font-semibold);
  color: var(--gray-900);
  margin: 0 0 var(--space-3);
}

.publication-card p {
  color: var(--gray-600);
  margin: 0 0 var(--space-6);
  line-height: 1.6;
}

.publication-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  color: var(--primary-600);
  text-decoration: none;
  font-weight: var(--font-medium);
  transition: var(--transition-colors);
}

.publication-link:hover {
  color: var(--primary-700);
}

/* Technology Section */
.technology {
  background: white;
}

.tech-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--space-6);
}

.tech-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-6);
  background: var(--gray-50);
  border-radius: var(--radius-xl);
  transition: var(--transition-base);
  border: 2px solid transparent;
}

.tech-item:hover {
  background: white;
  border-color: var(--primary-200);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.tech-item i {
  font-size: var(--text-3xl);
  color: var(--primary-600);
}

.tech-item span {
  font-weight: var(--font-medium);
  color: var(--gray-700);
}

/* Responsive Design */
@media (max-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr;
    gap: var(--space-8);
    text-align: center;
  }
  
  .hero-title {
    font-size: var(--text-4xl);
  }
  
  .hero-stats {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 768px) {
  .hero {
    padding: var(--space-16) 0 var(--space-12);
  }
  
  .hero-title {
    font-size: var(--text-3xl);
  }
  
  .hero-description {
    font-size: var(--text-lg);
  }
  
  .hero-buttons {
    flex-direction: column;
    align-items: center;
  }
  
  .hero-stats {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }
  
  section {
    padding: var(--space-12) 0;
  }
  
  .section-header h2 {
    font-size: var(--text-3xl);
  }
  
  .about-grid,
  .publications-grid {
    grid-template-columns: 1fr;
  }
  
  .tech-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-4);
  }
  
  .tech-grid {
    grid-template-columns: 1fr;
  }
  
  .hero-buttons {
    width: 100%;
  }
  
  .btn {
    width: 100%;
  }
}

/* Smooth scrolling */
html {
  scroll-behavior: smooth;
}

/* Focus styles for accessibility */
.btn:focus,
.nav-link:focus,
.publication-link:focus {
  outline: 2px solid var(--primary-500);
  outline-offset: 2px;
}

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

@keyframes fadeInLeft {
  from {
    opacity: 0;
    transform: translateX(-30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes fadeInRight {
  from {
    opacity: 0;
    transform: translateX(30px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

/* Animation classes */
.animate-fade-in-up {
  animation: fadeInUp 0.8s ease-out forwards;
}

.animate-fade-in-left {
  animation: fadeInLeft 0.8s ease-out forwards;
}

.animate-fade-in-right {
  animation: fadeInRight 0.8s ease-out forwards;
}

.animate-fade-in {
  animation: fadeIn 0.8s ease-out forwards;
}

/* Delay classes for staggered animations */
.delay-100 { animation-delay: 0.1s; }
.delay-200 { animation-delay: 0.2s; }
.delay-300 { animation-delay: 0.3s; }
.delay-400 { animation-delay: 0.4s; }
.delay-500 { animation-delay: 0.5s; }
.delay-600 { animation-delay: 0.6s; }
.delay-700 { animation-delay: 0.7s; }
.delay-800 { animation-delay: 0.8s; }
.delay-900 { animation-delay: 0.9s; }
.delay-1000 { animation-delay: 1.0s; }
.delay-1100 { animation-delay: 1.1s; }
.delay-1200 { animation-delay: 1.2s; }
.delay-1300 { animation-delay: 1.3s; }

/* Initial state for animated elements */
.animate-fade-in-up,
.animate-fade-in-left,
.animate-fade-in-right,
.animate-fade-in {
  opacity: 0;
}

/* Reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
  .animate-fade-in-up,
  .animate-fade-in-left,
  .animate-fade-in-right,
  .animate-fade-in {
    animation: none;
    opacity: 1;
    transform: none;
  }
}