/* CSS Variables */
:root {
  --primary-color: #4f46e5;
  --primary-dark: #4338ca;
  --secondary-color: #06b6d4;
  --text-color: #1f2937;
  --text-light: #6b7280;
  --bg-color: #ffffff;
  --bg-light: #f9fafb;
  --bg-dark: #111827;
  --border-color: #e5e7eb;
  --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--text-color);
  line-height: 1.6;
  background-color: var(--bg-color);
}

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

/* Header */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--bg-color);
  box-shadow: var(--shadow);
  z-index: 1000;
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.logo a {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary-color);
  text-decoration: none;
}

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

.nav a {
  color: var(--text-color);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
  position: relative;
}

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

.nav a::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary-color);
  transition: var(--transition);
}

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

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
}

.menu-toggle span {
  width: 25px;
  height: 3px;
  background: var(--text-color);
  transition: var(--transition);
}

/* Hero Section */
.hero {
  height: 100vh;
  min-height: 600px;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 0 20px;
}

.hero-content h1 {
  font-size: 3rem;
  margin-bottom: 20px;
  animation: fadeInUp 0.8s ease;
}

.hero-content p {
  font-size: 1.25rem;
  margin-bottom: 40px;
  opacity: 0.9;
  animation: fadeInUp 0.8s ease 0.2s both;
}

/* Buttons */
.btn {
  display: inline-block;
  padding: 12px 30px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition);
  cursor: pointer;
  border: none;
  font-size: 1rem;
}

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

.btn-primary:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
}

.btn-secondary {
  background: transparent;
  color: white;
  border: 2px solid white;
  margin-left: 15px;
}

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

/* Sections */
.section {
  padding: 100px 0;
}

.section-title {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 60px;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -15px;
  left: 50%;
  transform: translateX(-50%);
  width: 60px;
  height: 4px;
  background: var(--primary-color);
  border-radius: 2px;
}

/* About Section */
.about {
  background: var(--bg-light);
}

.about-content {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.about-text p {
  font-size: 1.1rem;
  color: var(--text-light);
  margin-bottom: 40px;
}

.stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
}

.stat-item {
  text-align: center;
  padding: 20px;
  background: var(--bg-color);
  border-radius: 12px;
  box-shadow: var(--shadow);
}

.stat-number {
  display: block;
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--primary-color);
}

.stat-label {
  color: var(--text-light);
}

.about-image .image-placeholder {
  background: var(--bg-color);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.about-image svg {
  width: 100%;
  height: auto;
}

/* Products Section */
.products-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.product-card {
  background: var(--bg-color);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  text-decoration: none;
  color: inherit;
  display: block;
}

.product-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-lg);
}

.product-image {
  height: 200px;
  background: linear-gradient(135deg, #e0e7ff 0%, #c7d2fe 100%);
  display: flex;
  align-items: center;
  justify-content: center;
}

.product-image svg {
  width: 80px;
  height: 80px;
}

.product-content {
  padding: 25px;
}

.product-content h3 {
  font-size: 1.25rem;
  margin-bottom: 10px;
  color: var(--text-color);
}

.product-content p {
  color: var(--text-light);
  margin-bottom: 15px;
}

.product-features {
  list-style: none;
}

.product-features li {
  padding: 5px 0;
  color: var(--text-light);
  font-size: 0.9rem;
}

.product-features li::before {
  content: '✓';
  color: var(--primary-color);
  margin-right: 8px;
}

.view-more {
  display: inline-block;
  margin-top: 15px;
  color: var(--primary-color);
  font-weight: 500;
  font-size: 0.9rem;
  transition: var(--transition);
}

.product-card:hover .view-more,
.news-card:hover .view-more {
  transform: translateX(5px);
}

/* News Section */
.news {
  background: var(--bg-light);
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
}

.news-card {
  background: var(--bg-color);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow);
  transition: var(--transition);
  text-decoration: none;
  color: inherit;
  display: block;
}

.news-card:hover {
  transform: translateY(-5px);
  box-shadow: var(--shadow-lg);
}

.news-content {
  padding: 25px;
}

.news-date {
  color: var(--primary-color);
  font-size: 0.9rem;
  font-weight: 500;
  margin-bottom: 10px;
}

.news-content h3 {
  font-size: 1.1rem;
  margin-bottom: 10px;
  color: var(--text-color);
}

.news-content p {
  color: var(--text-light);
  font-size: 0.95rem;
}

/* Contact Section */
.contact-content {
  display: grid;
  grid-template-columns: 1fr 1.5fr;
  gap: 60px;
}

.info-item {
  display: flex;
  gap: 20px;
  margin-bottom: 30px;
}

.info-icon {
  width: 50px;
  height: 50px;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.info-icon svg {
  width: 24px;
  height: 24px;
  stroke: white;
}

.info-text h4 {
  font-size: 1rem;
  margin-bottom: 5px;
}

.info-text p {
  color: var(--text-light);
}

.contact-form {
  background: var(--bg-light);
  padding: 40px;
  border-radius: 12px;
}

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

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
}

.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 15px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  font-size: 1rem;
  transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-message {
  margin-top: 20px;
  padding: 15px;
  border-radius: 8px;
  display: none;
}

.form-message.success {
  display: block;
  background: #d1fae5;
  color: #065f46;
}

.form-message.error {
  display: block;
  background: #fee2e2;
  color: #991b1b;
}

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

.footer-content {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-info h3 {
  font-size: 1.5rem;
  margin-bottom: 15px;
}

.footer-info p {
  color: #9ca3af;
}

.footer-links h4,
.footer-contact h4 {
  margin-bottom: 20px;
}

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

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

.footer-links a {
  color: #9ca3af;
  text-decoration: none;
  transition: var(--transition);
}

.footer-links a:hover {
  color: white;
}

.footer-contact p {
  color: #9ca3af;
  margin-bottom: 8px;
}

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid #374151;
  color: #9ca3af;
}

/* Download Page */
.download-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  margin-bottom: 20px;
}

.download-header h1 {
  font-size: 2rem;
  margin-bottom: 8px;
}

.download-subtitle {
  color: var(--text-light);
}

.download-toolbar {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  background: var(--bg-light);
  padding: 16px 20px;
  border-radius: 12px;
  margin-bottom: 30px;
}

.download-filters {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
}

.download-filter-label {
  color: var(--text-light);
  font-size: 0.9rem;
}

.download-filter-group {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.filter-chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  border-radius: 999px;
  border: 1px solid var(--border-color);
  background: #fff;
  font-size: 0.85rem;
  cursor: pointer;
  user-select: none;
}

.filter-chip input {
  accent-color: var(--primary-color);
}

.download-filter-select {
  padding: 8px 12px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  background: #fff;
  font-size: 0.95rem;
}

.download-search {
  display: flex;
  align-items: center;
  gap: 16px;
}

.download-search input {
  width: 260px;
  max-width: 100%;
  padding: 10px 14px;
  border-radius: 8px;
  border: 1px solid var(--border-color);
  font-size: 0.95rem;
}

.download-count {
  color: var(--text-light);
  font-size: 0.95rem;
}

.download-path {
  color: var(--text-light);
  font-size: 0.85rem;
  word-break: break-all;
}

.download-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.download-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  padding: 18px 20px;
  border: 1px solid var(--border-color);
  border-radius: 12px;
  box-shadow: var(--shadow);
  background: var(--bg-color);
}

.download-info h3 {
  margin-bottom: 6px;
  font-size: 1.1rem;
}

.download-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  color: var(--text-light);
  font-size: 0.9rem;
}

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

.download-btn:hover {
  background: var(--primary-color);
  color: #fff;
}

.download-pagination {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  margin-bottom: 30px;
  flex-wrap: wrap;
}

.page-info {
  color: var(--text-light);
  font-size: 0.95rem;
}

.download-empty,
.download-error {
  text-align: center;
  padding: 50px 20px;
  color: var(--text-light);
  background: var(--bg-light);
  border-radius: 12px;
}

/* Patents & Technology Showcase */
.showcase-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 20px;
  margin-bottom: 30px;
}

.showcase-subtitle {
  color: var(--text-light);
  font-size: 1rem;
}

.section-title.small {
  font-size: 1.8rem;
  margin-bottom: 30px;
}

.showcase-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
  margin-bottom: 50px;
}

.showcase-card {
  background: #fff;
  border-radius: 16px;
  padding: 16px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.showcase-card img {
  width: 100%;
  border-radius: 12px;
  background: var(--bg-light);
}

.showcase-info h3 {
  margin-bottom: 6px;
  font-size: 1.1rem;
}

.showcase-info p {
  color: var(--text-light);
  font-size: 0.95rem;
}

.video-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  margin-bottom: 20px;
}

.video-card {
  background: #fff;
  border-radius: 16px;
  padding: 16px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.video-card video {
  width: 100%;
  border-radius: 12px;
  background: #0f172a;
}

.video-note {
  color: var(--text-light);
  font-size: 0.9rem;
  margin-top: 10px;
}

.pdf-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  margin-bottom: 50px;
}

.pdf-card {
  background: #fff;
  border-radius: 16px;
  padding: 16px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.pdf-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
}

.pdf-meta h3 {
  font-size: 1.05rem;
}

.pdf-frame {
  width: 100%;
  min-height: 360px;
  border: 1px solid var(--border-color);
  border-radius: 12px;
  background: var(--bg-light);
}

.patent-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-bottom: 50px;
}

.patent-item {
  background: #fff;
  border-radius: 16px;
  padding: 20px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-color);
}

.patent-item h3 {
  margin-bottom: 8px;
  font-size: 1.15rem;
}

.patent-meta {
  color: var(--text-light);
  font-size: 0.9rem;
  margin-bottom: 8px;
}

.patent-summary,
.patent-claim {
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: 10px;
}

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

/* Responsive */
@media (max-width: 992px) {
  .about-content,
  .contact-content {
    grid-template-columns: 1fr;
  }

  .products-grid,
  .news-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

@media (max-width: 768px) {
  .menu-toggle {
    display: flex;
  }

  .nav {
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--bg-color);
    padding: 20px;
    box-shadow: var(--shadow);
    display: none;
  }

  .nav.active {
    display: block;
  }

  .nav ul {
    flex-direction: column;
    gap: 15px;
  }

  .hero-content h1 {
    font-size: 2rem;
  }

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

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

  .btn-secondary {
    margin-left: 0;
    margin-top: 15px;
  }

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

  .download-header {
    flex-direction: column;
    align-items: flex-start;
  }

  .download-toolbar {
    align-items: flex-start;
  }

  .download-search {
    width: 100%;
  }

  .download-search input {
    flex: 1;
  }

  .download-filters {
    width: 100%;
    justify-content: flex-start;
  }

  .download-item {
    flex-direction: column;
    align-items: flex-start;
  }

  .showcase-header {
    flex-direction: column;
    align-items: flex-start;
  }
}