:root {
  --primary: #003366;
  --secondary: #FF9900;
  --accent: #00CCFF;
  --bg-light: #F5F8FA;
  --text-dark: #333333;
  --text-light: #FFFFFF;
  --gray: #E0E0E0;
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

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

body {
  font-family: 'Open Sans', system-ui, -apple-system, sans-serif;
  line-height: 1.7;
  color: var(--text-dark);
  background: linear-gradient(135deg, #F5F8FA 0%, #E6ECF0 100%);
  min-height: 100%;
  overflow-x: hidden;
}

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

/* Header Styles */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(0, 51, 102, 0.95);
  backdrop-filter: blur(10px);
  z-index: 1000;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
  padding: 15px 0;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-light);
  text-decoration: none;
  display: flex;
  align-items: center;
}

.logo-icon {
  margin-right: 10px;
  width: 32px;
  height: 32px;
  background: var(--secondary);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.nav-item {
  margin-left: 30px;
  position: relative;
}

.nav-link {
  color: var(--text-light);
  text-decoration: none;
  font-weight: 600;
  font-size: 16px;
  transition: var(--transition);
  padding: 8px 0;
  position: relative;
}

.nav-link:hover {
  color: var(--secondary);
}

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

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

.dropdown {
  position: absolute;
  top: 100%;
  left: 0;
  background: white;
  min-width: 200px;
  border-radius: 8px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: var(--transition);
  z-index: 100;
}

.nav-item:hover .dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-item {
  padding: 12px 20px;
  border-bottom: 1px solid var(--gray);
  transition: var(--transition);
}

.dropdown-item:last-child {
  border-bottom: none;
}

.dropdown-item:hover {
  background: var(--bg-light);
  color: var(--primary);
}

/* Hero Section */
.hero {
  padding: 180px 0 100px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(circle, rgba(0, 204, 255, 0.1) 0%, rgba(0, 0, 0, 0) 70%);
  z-index: -1;
  animation: pulse 15s infinite alternate;
}

@keyframes pulse {
  0% {
    transform: scale(1);
  }
  100% {
    transform: scale(1.2);
  }
}

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

.hero-text h1 {
  font-size: 48px;
  font-weight: 800;
  margin-bottom: 20px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.2;
}

.hero-text p {
  font-size: 18px;
  color: var(--text-dark);
  margin-bottom: 30px;
  opacity: 0.9;
}

.hero-image {
  position: relative;
  border-radius: 20px;
  overflow: hidden;
  box-shadow: 0 30px 60px rgba(0, 51, 102, 0.2);
  transform: perspective(1000px) rotateY(-5deg);
  transition: var(--transition);
}

.hero-image:hover {
  transform: perspective(1000px) rotateY(0deg);
}

.hero-image img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 20px;
  transition: var(--transition);
}

.hero-image:hover img {
  transform: scale(1.05);
}

/* Main Content */
.main-content {
  padding: 80px 0;
}

.section-title {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 50px;
  text-align: center;
  position: relative;
  color: var(--primary);
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -15px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
  border-radius: 2px;
}

.article {
  background: white;
  border-radius: 16px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
  padding: 50px;
  margin-bottom: 60px;
}

.article h2 {
  font-size: 32px;
  color: var(--primary);
  margin-bottom: 20px;
  position: relative;
  padding-bottom: 15px;
}

.article h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: var(--secondary);
}

.article h3 {
  font-size: 24px;
  color: var(--primary);
  margin: 30px 0 15px;
}

.article p {
  font-size: 17px;
  line-height: 1.8;
  margin-bottom: 20px;
  color: #555;
}

.article span {
  font-weight: 600;
  color: var(--primary);
}

.article pre {
  background: #1E1E1E;
  border-radius: 8px;
  padding: 20px;
  margin: 25px 0;
  overflow: auto;
  box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.5);
}

.article code {
  font-family: 'Fira Code', monospace;
  font-size: 15px;
  color: #D4D4D4;
}

.article pre code {
  display: block;
  white-space: pre;
}

/* Grid System */
.grid-system {
  display: grid;
  grid-template-columns: repeat(12, 1fr);
  gap: 20px;
  margin: 40px 0;
}

.grid-item {
  background: white;
  border-radius: 8px;
  padding: 20px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
  transition: var(--transition);
}

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

/* Card Styles */
.card-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin: 40px 0;
}

.card {
  background: white;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
  transition: var(--transition);
}

.card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 40px rgba(0, 0, 0, 0.15);
}

.card-image {
  height: 200px;
  overflow: hidden;
}

.card-image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition);
}

.card:hover .card-image img {
  transform: scale(1.1);
}

.card-content {
  padding: 25px;
}

.card-title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 15px;
  color: var(--primary);
}

.card-text {
  color: #666;
  margin-bottom: 20px;
}

/* Table Styles */
.table-container {
  overflow-x: auto;
  margin: 40px 0;
}

.table {
  width: 100%;
  border-collapse: collapse;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
}

.table thead {
  background: linear-gradient(90deg, var(--primary), #004080);
  color: white;
}

.table th {
  padding: 15px;
  text-align: left;
  font-weight: 600;
}

.table td {
  padding: 12px 15px;
  border-bottom: 1px solid var(--gray);
}

.table tbody tr:last-child td {
  border-bottom: none;
}

.table tbody tr:hover {
  background: rgba(0, 51, 102, 0.03);
}

/* Footer */
.footer {
  background: var(--primary);
  color: white;
  padding: 60px 0 30px;
  position: relative;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 10px;
  background: linear-gradient(90deg, var(--secondary), var(--accent));
}

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

.footer-column h3 {
  font-size: 20px;
  margin-bottom: 20px;
  position: relative;
  padding-bottom: 10px;
}

.footer-column h3::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 40px;
  height: 2px;
  background: var(--secondary);
}

.footer-column p {
  margin-bottom: 15px;
  opacity: 0.8;
}

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

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

.footer-links a {
  color: white;
  text-decoration: none;
  opacity: 0.8;
  transition: var(--transition);
}

.footer-links a:hover {
  opacity: 1;
  color: var(--secondary);
  padding-left: 5px;
}

.footer-bottom {
  text-align: center;
  padding-top: 30px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.notice {
  background: rgba(255, 255, 255, 0.1);
  padding: 15px;
  border-radius: 8px;
  margin-top: 20px;
  text-align: center;
  font-size: 14px;
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.section {
  opacity: 0;
  animation: fadeInUp 0.6s forwards;
}

.section.visible {
  opacity: 1;
}

/* Responsive */
@media (max-width: 992px) {
  .hero-content {
    grid-template-columns: 1fr;
  }
  
  .hero-text {
    order: 1;
    text-align: center;
  }
  
  .hero-image {
    order: 2;
    max-width: 600px;
    margin: 0 auto;
  }
  
  .nav-menu {
    display: none;
  }
}

@media (max-width: 768px) {
  .hero-text h1 {
    font-size: 36px;
  }
  
  .section-title {
    font-size: 30px;
  }
  
  .article {
    padding: 30px;
  }
  
  .article h2 {
    font-size: 28px;
  }
  
  .article h3 {
    font-size: 22px;
  }
}

@media (max-width: 576px) {
  .hero {
    padding: 150px 0 80px;
  }
  
  .hero-text h1 {
    font-size: 30px;
  }
  
  .section-title {
    font-size: 26px;
  }
  
  .article {
    padding: 25px;
  }
  
  .article h2 {
    font-size: 24px;
  }
  
  .article h3 {
    font-size: 20px;
  }
  
  .article p {
    font-size: 16px;
  }
}