:root {
  --primary-color: #0D47A1;
  --secondary-color: #1976D2;
  --accent-color: #FF6F00;
  --neutral-light: #ECEFF1;
  --neutral-dark: #263238;
  --text-light: #FFFFFF;
  --text-dark: #212121;
  --gradient-blue: linear-gradient(135deg, #0D47A1 0%, #1976D2 100%);
  --gradient-orange: linear-gradient(135deg, #FF6F00 0%, #FFA000 100%);
  --shadow-sm: 0 4px 6px rgba(0,0,0,0.1);
  --shadow-md: 0 8px 16px rgba(0,0,0,0.15);
  --shadow-lg: 0 12px 24px rgba(0,0,0,0.2);
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

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

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

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

.header {
  background: var(--gradient-blue);
  color: var(--text-light);
  padding: 2rem 0;
  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') no-repeat;
  background-size: 30%;
  background-position: right bottom;
  opacity: 0.1;
  z-index: 0;
}

.header-content {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 2rem;
}

.header-title {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.header-subtitle {
  font-size: 1.25rem;
  max-width: 800px;
  margin-bottom: 2rem;
  opacity: 0.9;
}

.notice {
  background-color: rgba(255,255,255,0.2);
  padding: 1rem;
  border-radius: 8px;
  margin-top: 2rem;
  backdrop-filter: blur(5px);
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background-color: var(--neutral-dark);
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-logo {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--text-light);
  text-decoration: none;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: 2rem;
}

.nav-link {
  color: var(--text-light);
  text-decoration: none;
  font-weight: 500;
  position: relative;
  padding: 0.5rem 0;
  transition: var(--transition);
}

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

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

.main {
  padding: 3rem 0;
}

.article {
  background-color: var(--text-light);
  border-radius: 12px;
  box-shadow: var(--shadow-md);
  padding: 3rem;
  margin-bottom: 3rem;
}

.article h2 {
  color: var(--primary-color);
  font-size: 2rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent-color);
}

.article h3 {
  color: var(--secondary-color);
  font-size: 1.5rem;
  margin: 2rem 0 1rem;
}

.article p {
  margin-bottom: 1.5rem;
  font-size: 1.1rem;
  line-height: 1.8;
}

.code-block {
  background-color: var(--neutral-dark);
  color: #f8f8f2;
  padding: 1.5rem;
  border-radius: 8px;
  margin: 1.5rem 0;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  box-shadow: var(--shadow-sm);
}

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

.gallery {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

.gallery-item {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: var(--transition);
}

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

.gallery-item img {
  width: 100%;
  height: auto;
  display: block;
}

.footer {
  background-color: var(--neutral-dark);
  color: var(--text-light);
  padding: 3rem 0;
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.footer-section h3 {
  color: var(--accent-color);
  margin-bottom: 1.5rem;
  font-size: 1.25rem;
}

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

.footer-links li {
  margin-bottom: 0.75rem;
}

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

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

.copyright {
  text-align: center;
  margin-top: 2rem;
  padding-top: 2rem;
  border-top: 1px solid rgba(255,255,255,0.1);
}

@media (max-width: 768px) {
  .header-title {
    font-size: 2rem;
  }
  
  .header-subtitle {
    font-size: 1rem;
  }
  
  .nav-menu {
    gap: 1rem;
  }
  
  .article {
    padding: 2rem;
  }
  
  .gallery {
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
  }
}

@media (max-width: 480px) {
  .navbar {
    flex-direction: column;
    padding: 1rem;
  }
  
  .nav-menu {
    margin-top: 1rem;
    flex-wrap: wrap;
    justify-content: center;
  }
  
  .article {
    padding: 1.5rem;
  }
  
  .article h2 {
    font-size: 1.75rem;
  }
  
  .article h3 {
    font-size: 1.25rem;
  }
}

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

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