:root {
  --primary-color: #003366;
  --secondary-color: #66ccff;
  --accent-color: #ff9933;
  --background-color: #f0f4f8;
  --text-color: #333333;
  --card-shadow: 0 10px 30px -15px rgba(0, 51, 102, 0.3);
  --transition: all 0.4s cubic-bezier(0.215, 0.61, 0.355, 1);
}

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

body {
  background: linear-gradient(135deg, #f5f9fc 0%, #e6f0f7 100%);
  color: var(--text-color);
  font-family: 'Roboto', sans-serif;
  line-height: 1.7;
  overflow-x: hidden;
  padding-top: 80px;
}

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

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 1000;
  background: linear-gradient(90deg, var(--primary-color) 0%, #004080 100%);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
  backdrop-filter: blur(5px);
  -webkit-backdrop-filter: blur(5px);
  padding: 15px 0;
}

.navbar {
  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: white;
  text-decoration: none;
  font-weight: 500;
  font-size: 16px;
  position: relative;
  transition: var(--transition);
  padding: 5px 0;
}

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

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

.banner {
  background: linear-gradient(135deg, rgba(0, 51, 102, 0.9) 0%, rgba(102, 204, 255, 0.8) 100%);
  color: white;
  padding: 80px 0;
  margin-bottom: 60px;
  position: relative;
  overflow: hidden;
  border-radius: 0 0 20px 20px;
}

.banner::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;
}

.banner-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

.banner h1 {
  font-size: 2.8rem;
  margin-bottom: 20px;
  text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.banner p {
  font-size: 1.2rem;
  margin-bottom: 30px;
  opacity: 0.9;
}

.notice {
  background: rgba(255, 255, 255, 0.2);
  padding: 15px;
  border-radius: 8px;
  margin: 40px auto;
  max-width: 800px;
  text-align: center;
  border: 1px solid rgba(255, 255, 255, 0.3);
  backdrop-filter: blur(5px);
}

article {
  background: white;
  border-radius: 16px;
  box-shadow: var(--card-shadow);
  padding: 50px;
  margin-bottom: 60px;
}

article h2 {
  color: var(--primary-color);
  font-size: 2rem;
  margin-bottom: 30px;
  position: relative;
  padding-bottom: 15px;
}

article h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 4px;
  background: linear-gradient(90deg, var(--accent-color) 0%, var(--secondary-color) 100%);
  border-radius: 2px;
}

article h3 {
  color: var(--primary-color);
  font-size: 1.5rem;
  margin: 40px 0 20px;
}

article p {
  margin-bottom: 20px;
  font-size: 1.1rem;
  line-height: 1.8;
}

article strong {
  color: var(--primary-color);
}

article em {
  color: var(--accent-color);
  font-style: normal;
  font-weight: 500;
}

.color-sample {
  display: inline-block;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  vertical-align: middle;
  margin: 0 5px;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.2);
}

pre {
  background: #f8fafc;
  border-radius: 8px;
  padding: 20px;
  margin: 30px 0;
  overflow: auto;
  border-left: 4px solid var(--accent-color);
  font-size: 0.95rem;
  line-height: 1.6;
}

code {
  font-family: 'Courier New', monospace;
  color: #2d3748;
}

.highlight-box {
  background: linear-gradient(135deg, rgba(102, 204, 255, 0.1) 0%, rgba(0, 51, 102, 0.1) 100%);
  border-radius: 12px;
  padding: 30px;
  margin: 40px 0;
  border: 1px solid rgba(102, 204, 255, 0.3);
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  margin: 40px 0;
}

.image-card {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.1);
  transition: var(--transition);
  position: relative;
}

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

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

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

.footer {
  background: linear-gradient(135deg, var(--primary-color) 0%, #002244 100%);
  color: white;
  padding: 50px 0;
  text-align: center;
  margin-top: 60px;
}

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

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

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

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

@media (max-width: 768px) {
  .nav-links {
    gap: 15px;
  }
  
  .banner h1 {
    font-size: 2rem;
  }
  
  article {
    padding: 30px;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.floating {
  animation: float 3s ease-in-out infinite;
}