:root {
  --primary: #0B4F6C;
  --secondary: #34C759;
  --accent: #FFA500;
  --light: #E5E5EA;
  --dark: #1A1A1A;
  --gradient: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
}

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

body {
  background-color: #f9f9f9;
  color: #333;
  line-height: 1.6;
  overflow-x: hidden;
}

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

.header {
  background: var(--gradient);
  color: white;
  padding: 2rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  margin-bottom: 3rem;
}

.header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center right;
  opacity: 0.1;
  z-index: 0;
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  position: relative;
  z-index: 1;
  text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.header p {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.note {
  background-color: var(--light);
  padding: 1rem;
  border-left: 4px solid var(--accent);
  margin: 2rem 0;
  font-size: 0.9rem;
}

.navbar {
  position: sticky;
  top: 0;
  background-color: var(--primary);
  padding: 1rem 0;
  z-index: 1000;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.nav-links {
  display: flex;
  gap: 2rem;
}

.nav-links a {
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
  position: relative;
  padding: 0.5rem 0;
}

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

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

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

.content-section {
  background-color: white;
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.05);
  padding: 2.5rem;
  margin-bottom: 3rem;
  position: relative;
  overflow: hidden;
}

.content-section::before {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 150px;
  height: 150px;
  background: url('https://images.gptkong.com/demo/sample2.png') no-repeat;
  background-size: contain;
  opacity: 0.1;
  z-index: 0;
}

.content-section h2 {
  color: var(--primary);
  margin-bottom: 1.5rem;
  font-size: 1.8rem;
  position: relative;
  z-index: 1;
}

.content-section h3 {
  color: var(--secondary);
  margin: 1.5rem 0 1rem;
  font-size: 1.4rem;
  position: relative;
  z-index: 1;
}

.content-section p {
  margin-bottom: 1.2rem;
  position: relative;
  z-index: 1;
}

.content-section img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
  margin: 1.5rem 0;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.content-section img:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

pre {
  background-color: #f5f5f5;
  border-radius: 6px;
  padding: 1.5rem;
  overflow-x: auto;
  margin: 1.5rem 0;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  position: relative;
  z-index: 1;
}

code {
  background-color: #f5f5f5;
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
  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: transform 0.3s ease;
}

.image-grid img:hover {
  transform: scale(1.03);
}

.footer {
  background-color: var(--dark);
  color: white;
  padding: 3rem 0;
  text-align: center;
  margin-top: 3rem;
}

.footer p {
  margin-bottom: 1rem;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-top: 1.5rem;
}

.footer-links a {
  color: white;
  text-decoration: none;
  transition: color 0.3s ease;
}

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

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

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.animated {
  animation: fadeIn 0.8s ease-out forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }