:root {
  --primary: #1E3C72;
  --secondary: #2A5298;
  --accent: #4A90E2;
  --highlight: #FF7F50;
  --text: #FFFFFF;
  --bg: #0A192F;
  --card-bg: rgba(255, 255, 255, 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;
}

.header {
  text-align: center;
  padding: 3rem 2rem;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  margin-bottom: 3rem;
  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;
  opacity: 0.2;
  z-index: -1;
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  background: linear-gradient(90deg, #FFFFFF, #4A90E2);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

h2 {
  font-size: 1.8rem;
  margin: 2rem 0 1rem;
  color: var(--accent);
  position: relative;
  padding-left: 1rem;
}

h2::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 4px;
  background: var(--highlight);
}

h3 {
  font-size: 1.5rem;
  margin: 1.5rem 0 0.8rem;
  color: var(--text);
}

p {
  margin-bottom: 1.2rem;
  font-size: 1.1rem;
}

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

.card {
  background: var(--card-bg);
  border-radius: 12px;
  padding: 2rem;
  margin: 2rem 0;
  backdrop-filter: blur(10px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.3);
}

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

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

.img-container img {
  width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
  transition: transform 0.3s ease;
}

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

pre {
  background: rgba(0, 0, 0, 0.3);
  border-radius: 8px;
  padding: 1.5rem;
  margin: 1.5rem 0;
  overflow-x: auto;
  position: relative;
}

code {
  font-family: 'Courier New', monospace;
  color: #FFD700;
}

.note {
  background: rgba(255, 215, 0, 0.1);
  border-left: 4px solid #FFD700;
  padding: 1rem;
  margin: 1.5rem 0;
  border-radius: 0 4px 4px 0;
}

.footer {
  text-align: center;
  padding: 2rem;
  margin-top: 3rem;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  position: relative;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://images.gptkong.com/demo/sample12.png') center/cover;
  opacity: 0.1;
  z-index: -1;
}

@media (max-width: 768px) {
  .header {
    padding: 2rem 1rem;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  .container {
    padding: 0 1rem;
  }
  
  .card {
    padding: 1.5rem;
  }
}

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

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