:root {
  --primary: #007BFF;
  --secondary: #FF9800;
  --accent: #4CAF50;
  --bg-light: #f5f5f5;
  --text-dark: #333;
  --text-light: #fff;
}

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

body {
  font-family: 'Roboto', 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-dark);
  background: linear-gradient(135deg, #f9f9f9 0%, #e6f2ff 100%);
  min-height: 100%;
  overflow-x: hidden;
}

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

.header {
  background: linear-gradient(90deg, var(--primary) 0%, #0056b3 100%);
  color: var(--text-light);
  padding: 40px 0;
  text-align: center;
  border-radius: 0 0 20px 20px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
  margin-bottom: 50px;
  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: 90% center;
  opacity: 0.1;
}

h1, h2, h3, h4 {
  font-weight: 700;
  margin-bottom: 1.5rem;
  line-height: 1.3;
}

h1 {
  font-size: 2.5rem;
  color: var(--text-light);
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
}

h2 {
  font-size: 1.8rem;
  color: var(--primary);
  padding-bottom: 10px;
  border-bottom: 2px solid var(--secondary);
  margin-top: 3rem;
}

h3 {
  font-size: 1.5rem;
  color: var(--secondary);
  margin-top: 2rem;
}

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

.note {
  background: rgba(255, 152, 0, 0.1);
  border-left: 4px solid var(--secondary);
  padding: 20px;
  margin: 30px 0;
  border-radius: 0 8px 8px 0;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
  gap: 30px;
  margin: 40px 0;
}

.card {
  background: white;
  border-radius: 12px;
  padding: 30px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.1);
}

.img-container {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  margin: 30px 0;
  justify-content: center;
}

.img-box {
  width: 320px;
  height: 320px;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
  transition: all 0.3s ease;
}

.img-box:hover {
  transform: scale(1.03);
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.15);
}

.img-box img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

pre {
  background: #2d2d2d;
  color: #f8f8f2;
  padding: 20px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 30px 0;
  font-size: 0.9rem;
  line-height: 1.5;
  box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.5);
}

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

.footer {
  background: linear-gradient(90deg, var(--primary) 0%, #0056b3 100%);
  color: var(--text-light);
  padding: 30px 0;
  text-align: center;
  margin-top: 80px;
  border-radius: 20px 20px 0 0;
}

.nav {
  position: sticky;
  top: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  padding: 15px 0;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  z-index: 1000;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

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

.nav-links a {
  color: var(--primary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
}

.nav-links a:hover {
  color: var(--secondary);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--secondary);
  transition: width 0.3s ease;
}

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

.badge {
  display: inline-block;
  padding: 5px 10px;
  background: var(--secondary);
  color: white;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: bold;
  margin-left: 10px;
  vertical-align: middle;
}

.highlight {
  background: linear-gradient(120deg, rgba(0, 123, 255, 0.2) 0%, rgba(0, 123, 255, 0) 100%);
  padding: 2px 5px;
  border-radius: 3px;
}

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

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

@media (max-width: 768px) {
  .grid {
    grid-template-columns: 1fr;
  }
  
  .nav-links {
    gap: 15px;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
}