:root {
  --primary: #66a6ff;
  --secondary: #89f7fe;
  --accent: #ff7f50;
  --dark: #2c3e50;
  --light: #f8f9fa;
  --glass: rgba(255, 255, 255, 0.2);
  --transition: all 0.3s ease;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Roboto', sans-serif;
}

body {
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
  color: var(--dark);
  line-height: 1.6;
  overflow-x: hidden;
}

header {
  position: relative;
  padding: 2rem 0;
  text-align: center;
  background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
  color: white;
  margin-bottom: 3rem;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
}

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

.header-content {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.subtitle {
  font-size: 1.2rem;
  opacity: 0.9;
  margin-bottom: 2rem;
}

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

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 2rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
  gap: 2rem;
  margin-bottom: 3rem;
}

.card {
  background: var(--glass);
  border-radius: 15px;
  padding: 2rem;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.3);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
  transition: var(--transition);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 60px rgba(0, 0, 0, 0.2);
}

h2 {
  color: var(--primary);
  margin-bottom: 1.5rem;
  font-size: 1.8rem;
  position: relative;
  padding-bottom: 0.5rem;
}

h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
}

p {
  margin-bottom: 1.5rem;
  font-size: 1.1rem;
}

pre {
  background: rgba(0,0,0,0.8);
  color: #f8f8f2;
  padding: 1.5rem;
  border-radius: 8px;
  overflow: auto;
  margin: 1.5rem 0;
  font-family: 'Courier New', monospace;
  font-size: 0.95rem;
  line-height: 1.5;
  box-shadow: 0 4px 20px rgba(0,0,0,0.2);
}

code {
  font-family: 'Courier New', monospace;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 1rem;
  margin: 2rem 0;
}

.image-grid img {
  width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
  transition: var(--transition);
}

.image-grid img:hover {
  transform: scale(1.05);
  box-shadow: 0 8px 25px rgba(0,0,0,0.2);
}

.nav-links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 1rem;
  margin: 2rem 0;
}

.nav-link {
  padding: 0.8rem 1.5rem;
  background: var(--glass);
  border-radius: 50px;
  color: var(--dark);
  text-decoration: none;
  transition: var(--transition);
  backdrop-filter: blur(5px);
  border: 1px solid rgba(255,255,255,0.3);
}

.nav-link:hover {
  background: rgba(255,255,255,0.3);
  transform: translateY(-3px);
}

footer {
  text-align: center;
  padding: 2rem;
  margin-top: 3rem;
  background: linear-gradient(135deg, var(--dark) 0%, #34495e 100%);
  color: white;
}

@media (max-width: 768px) {
  .grid {
    grid-template-columns: 1fr;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  .subtitle {
    font-size: 1rem;
  }
  
  .card {
    padding: 1.5rem;
  }
}

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

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

.highlight {
  background: linear-gradient(90deg, rgba(102,166,255,0.2) 0%, rgba(137,247,254,0.2) 100%);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
}