:root {
  --primary-color: #0D47A1;
  --secondary-color: #1565C0;
  --accent-color: #FF9800;
  --text-color: #333333;
  --light-bg: #F5F7FA;
  --dark-bg: #263238;
  --white: #FFFFFF;
  --gray: #ECEFF1;
  --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500;700&family=Lato:wght@300;400;700&display=swap');

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

body {
  font-family: 'Lato', sans-serif;
  color: var(--text-color);
  background-color: var(--light-bg);
  line-height: 1.6;
  padding-top: 80px;
  overflow-x: hidden;
}

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: var(--white);
  padding: 1rem 2rem;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
  z-index: 1000;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.header h1 {
  font-family: 'Roboto', sans-serif;
  font-weight: 500;
  font-size: 1.5rem;
  background: linear-gradient(to right, var(--white), #BBDEFB);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav {
  display: flex;
  gap: 1.5rem;
}

.nav a {
  color: var(--white);
  text-decoration: none;
  font-family: 'Roboto', sans-serif;
  font-weight: 400;
  padding: 0.5rem 1rem;
  border-radius: 4px;
  transition: var(--transition);
  position: relative;
}

.nav a:hover {
  background-color: rgba(255, 255, 255, 0.1);
}

.nav a::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background-color: var(--accent-color);
  transition: var(--transition);
}

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

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

.hero {
  background: linear-gradient(135deg, rgba(13, 71, 161, 0.9), rgba(21, 101, 192, 0.9)), url('https://images.gptkong.com/demo/sample1.png');
  background-size: cover;
  background-position: center;
  color: var(--white);
  padding: 4rem 2rem;
  border-radius: 12px;
  margin-bottom: 3rem;
  text-align: center;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle at 20% 50%, rgba(255, 152, 0, 0.2), transparent 70%);
}

.hero h2 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  font-weight: 700;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

.hero p {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 0 auto 2rem;
  opacity: 0.9;
}

.notice {
  background-color: var(--white);
  color: var(--primary-color);
  padding: 1rem;
  border-radius: 8px;
  margin: 2rem auto;
  text-align: center;
  max-width: 800px;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  border-left: 4px solid var(--accent-color);
  font-weight: 500;
}

article {
  background-color: var(--white);
  padding: 3rem;
  border-radius: 12px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
  margin-bottom: 3rem;
}

article h2 {
  color: var(--primary-color);
  font-size: 2rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent-color);
  font-family: 'Roboto', sans-serif;
}

article h3 {
  color: var(--secondary-color);
  font-size: 1.5rem;
  margin: 2rem 0 1rem;
  font-family: 'Roboto', sans-serif;
}

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

article strong {
  color: var(--primary-color);
}

article em {
  color: var(--secondary-color);
  font-style: italic;
}

article code {
  background-color: var(--gray);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  font-family: monospace;
  color: #E91E63;
}

pre {
  background-color: var(--dark-bg);
  color: #ECEFF1;
  padding: 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1.5rem 0;
  box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.3);
  font-size: 0.95rem;
  line-height: 1.5;
}

pre code {
  background-color: transparent;
  padding: 0;
  color: inherit;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 2rem 0;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  border-radius: 8px;
  overflow: hidden;
}

table th {
  background-color: var(--primary-color);
  color: var(--white);
  padding: 1rem;
  text-align: left;
  font-family: 'Roboto', sans-serif;
}

table td {
  padding: 1rem;
  border-bottom: 1px solid var(--gray);
  vertical-align: top;
}

table tr:nth-child(even) {
  background-color: rgba(236, 239, 241, 0.5);
}

table tr:hover {
  background-color: rgba(13, 71, 161, 0.05);
}

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

.image-card {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  transition: var(--transition);
  position: relative;
}

.image-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

.image-card img {
  width: 100%;
  height: 300px;
  object-fit: cover;
  display: block;
  transition: var(--transition);
}

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

.image-card::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(to top, rgba(0, 0, 0, 0.5), transparent);
  opacity: 0;
  transition: var(--transition);
}

.image-card:hover::after {
  opacity: 1;
}

.footer {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: var(--white);
  padding: 2rem;
  text-align: center;
  border-radius: 12px;
  margin-top: 3rem;
}

.footer p {
  margin-bottom: 0;
}

.scroll-animation {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.scroll-animation.visible {
  opacity: 1;
  transform: translateY(0);
}

@media (max-width: 768px) {
  .header {
    flex-direction: column;
    padding: 1rem;
  }
  
  .nav {
    margin-top: 1rem;
    flex-wrap: wrap;
    justify-content: center;
  }
  
  .hero h2 {
    font-size: 2rem;
  }
  
  article {
    padding: 2rem 1.5rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 3rem 1rem;
  }
  
  .hero h2 {
    font-size: 1.8rem;
  }
  
  article {
    padding: 1.5rem 1rem;
  }
  
  pre {
    padding: 1rem;
    font-size: 0.85rem;
  }
}