:root {
  --primary: #1e88e5;
  --primary-light: #42a5f5;
  --primary-dark: #1565c0;
  --secondary: #78909c;
  --accent: #ff7043;
  --bg-light: #f5f7fa;
  --text-dark: #263238;
  --text-light: #eceff1;
  --card-bg: rgba(255, 255, 255, 0.85);
  --glass: rgba(255, 255, 255, 0.15);
}

@font-face {
  font-family: 'Roboto';
  src: local('Roboto'), url(https://fonts.gstatic.com/s/roboto/v30/KFOmCnqEu92Fr1Mu4mxK.woff2) format('woff2');
  font-display: swap;
}

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

body {
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  color: var(--text-dark);
  background: linear-gradient(135deg, var(--bg-light), #ffffff);
  background-attachment: fixed;
  min-height: 100%;
}

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

header {
  background: linear-gradient(45deg, var(--primary), var(--primary-dark));
  color: white;
  padding: 2rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

header::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://images.gptkong.com/demo/sample3.png') center/cover;
  opacity: 0.1;
  z-index: 0;
}

.header-content {
  position: relative;
  z-index: 1;
  max-width: 800px;
  margin: 0 auto;
}

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

.subtitle {
  font-size: 1.2rem;
  opacity: 0.9;
  margin-bottom: 1.5rem;
}

.note {
  background: var(--glass);
  backdrop-filter: blur(10px);
  padding: 1rem;
  border-radius: 8px;
  margin: 2rem auto;
  max-width: 800px;
  text-align: center;
  font-weight: bold;
  box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

.navbar {
  background: rgba(30, 136, 229, 0.95);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 1000;
  padding: 1rem 0;
  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: 1.5rem;
}

.nav-links a {
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  padding: 0.5rem 1rem;
  border-radius: 4px;
}

.nav-links a:hover {
  background: rgba(255,255,255,0.2);
  transform: translateY(-2px);
}

.main-content {
  padding: 3rem 0;
}

article {
  background: white;
  border-radius: 12px;
  box-shadow: 0 8px 30px rgba(0,0,0,0.08);
  padding: 2.5rem;
  margin-bottom: 3rem;
}

h2 {
  color: var(--primary-dark);
  font-size: 1.8rem;
  margin: 2rem 0 1.5rem;
  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(--accent));
}

h3 {
  color: var(--primary);
  font-size: 1.4rem;
  margin: 1.5rem 0 1rem;
}

p {
  margin-bottom: 1.2rem;
  font-size: 1.05rem;
}

.code-container {
  position: relative;
  margin: 1.5rem 0;
}

pre {
  background: #2d2d2d;
  color: #f8f8f2;
  padding: 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  font-size: 0.95rem;
  line-height: 1.5;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

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

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
  margin: 2rem 0;
}

.image-card {
  background: white;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.image-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.15);
}

.image-card img {
  width: 100%;
  height: auto;
  display: block;
}

.card {
  background: var(--card-bg);
  backdrop-filter: blur(8px);
  border-radius: 12px;
  padding: 2rem;
  margin: 2rem 0;
  box-shadow: 0 8px 30px rgba(0,0,0,0.08);
  border: 1px solid rgba(255,255,255,0.2);
}

.button {
  display: inline-block;
  background: linear-gradient(45deg, var(--primary), var(--primary-light));
  color: white;
  padding: 0.8rem 1.5rem;
  border-radius: 50px;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  box-shadow: 0 4px 8px rgba(30, 136, 229, 0.3);
  margin: 1rem 0;
}

.button:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 12px rgba(30, 136, 229, 0.4);
  background: linear-gradient(45deg, var(--primary-light), var(--primary));
}

footer {
  background: linear-gradient(45deg, var(--primary-dark), var(--primary));
  color: white;
  padding: 2rem 0;
  text-align: center;
  margin-top: 3rem;
}

@media (max-width: 768px) {
  h1 {
    font-size: 2rem;
  }
  
  .nav-links {
    gap: 0.8rem;
  }
  
  article {
    padding: 1.5rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

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

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