:root {
  --primary: #0F4C81;
  --secondary: #1E90FF;
  --accent: #00CED1;
  --bg: #E5E5E5;
  --text: #333333;
  --light: #FFFFFF;
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

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

body {
  font-family: 'Roboto', sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  overflow-x: hidden;
}

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

.header {
  background: linear-gradient(135deg, var(--primary), #003366);
  color: var(--light);
  padding: 100px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
  opacity: 0.1;
  z-index: 0;
}

.header h1 {
  font-size: 3rem;
  margin-bottom: 20px;
  position: relative;
  z-index: 1;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
}

.header p {
  font-size: 1.2rem;
  max-width: 700px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(15, 76, 129, 0.9);
  backdrop-filter: blur(10px);
  padding: 15px 0;
  z-index: 1000;
  box-shadow: var(--shadow);
}

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

.nav-links {
  display: flex;
  gap: 30px;
}

.nav-links a {
  color: var(--light);
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  position: relative;
  padding: 5px 0;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width 0.3s ease;
}

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

.brand {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--light);
}

.notice {
  background: var(--light);
  padding: 15px;
  border-radius: 8px;
  margin: 20px 0;
  text-align: center;
  box-shadow: var(--shadow);
  color: var(--primary);
  font-weight: 500;
}

.content-section {
  padding: 80px 0;
  position: relative;
}

.section-title {
  font-size: 2rem;
  color: var(--primary);
  margin-bottom: 40px;
  text-align: center;
  position: relative;
}

.section-title::after {
  content: '';
  position: absolute;
  bottom: -10px;
  left: 50%;
  transform: translateX(-50%);
  width: 80px;
  height: 3px;
  background: linear-gradient(to right, var(--secondary), var(--accent));
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin-top: 40px;
}

.card {
  background: var(--light);
  border-radius: 12px;
  padding: 30px;
  box-shadow: var(--shadow);
  transition: all 0.3s ease;
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 5px;
  height: 100%;
  background: linear-gradient(to bottom, var(--secondary), var(--accent));
  transition: width 0.3s ease;
}

.card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
}

.card:hover::before {
  width: 10px;
}

.card-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: 8px;
  margin-bottom: 20px;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s ease;
}

.card:hover .card-img {
  transform: scale(1.03);
}

.card-title {
  font-size: 1.5rem;
  color: var(--primary);
  margin-bottom: 15px;
}

.card-content {
  color: var(--text);
  margin-bottom: 20px;
}

.tag {
  display: inline-block;
  background: linear-gradient(to right, var(--secondary), var(--accent));
  color: var(--light);
  padding: 5px 15px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
}

.article {
  background: var(--light);
  border-radius: 12px;
  padding: 40px;
  box-shadow: var(--shadow);
  margin: 40px 0;
}

.article h2 {
  color: var(--primary);
  margin: 30px 0 20px;
  font-size: 1.8rem;
}

.article h3 {
  color: var(--secondary);
  margin: 25px 0 15px;
  font-size: 1.4rem;
}

.article p {
  margin-bottom: 20px;
  font-size: 1.1rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 25px 0;
  box-shadow: var(--shadow);
  border-radius: 8px;
  overflow: hidden;
}

thead {
  background: linear-gradient(to right, var(--primary), var(--secondary));
  color: var(--light);
}

th {
  padding: 15px;
  text-align: left;
}

td {
  padding: 15px;
  background: var(--light);
  border-bottom: 1px solid #eee;
}

pre {
  background: #f8f8f8;
  padding: 15px;
  border-radius: 8px;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  line-height: 1.5;
}

code {
  background: #f8f8f8;
  padding: 2px 5px;
  border-radius: 4px;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
}

.footer {
  background: linear-gradient(135deg, var(--primary), #003366);
  color: var(--light);
  padding: 50px 0;
  text-align: center;
}

.footer p {
  margin-bottom: 20px;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-bottom: 30px;
}

.footer-links a {
  color: var(--light);
  text-decoration: none;
  transition: color 0.3s ease;
}

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

@media (max-width: 768px) {
  .header h1 {
    font-size: 2rem;
  }
  
  .nav-links {
    gap: 15px;
  }
  
  .grid {
    grid-template-columns: 1fr;
  }
  
  .article {
    padding: 20px;
  }
}

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

.floating {
  animation: float 6s ease-in-out infinite;
}

.data-flow {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  pointer-events: none;
  z-index: 0;
}

.line {
  position: absolute;
  top: 50%;
  left: -10%;
  width: 200%;
  height: 2px;
  background: linear-gradient(to right, var(--secondary), rgba(30, 144, 255, 0));
  animation: flow 5s linear infinite;
  opacity: 0.5;
}

@keyframes flow {
  from {
    transform: translateX(-100%);
  }
  to {
    transform: translateX(100%);
  }
}

.fade-in {
  opacity: 0;
  animation: fadeInUp 1s forwards;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(40px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.visible {
  opacity: 1;
}