:root {
  --primary-bg-color: #f5f5f5;
  --secondary-bg-color: #fff8e1;
  --accent-color: #ff9800;
  --trust-color: #3f51b5;
  --gradient-start: #9c27b0;
  --gradient-end: #00bcd4;
  --text-color: #333;
  --light-gray: #e0e0e0;
  --dark-gray: #757575;
}

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

body {
  background-color: var(--primary-bg-color);
  color: var(--text-color);
  line-height: 1.6;
  padding-top: 80px;
}

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

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  color: white;
  padding: 20px 0;
  z-index: 1000;
  box-shadow: 0 4px 12px rgba(0,0,0,0.1);
}

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

.logo {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 1px;
}

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

.nav-link {
  color: white;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
  position: relative;
}

.nav-link:hover {
  opacity: 0.8;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: white;
  transition: width 0.3s ease;
}

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

.hero {
  background: linear-gradient(rgba(0,0,0,0.5), rgba(0,0,0,0.5)), url('https://images.gptkong.com/demo/sample1.png');
  background-size: cover;
  background-position: center;
  height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  text-align: center;
  margin-bottom: 60px;
  border-radius: 0 0 20px 20px;
  box-shadow: 0 10px 20px rgba(0,0,0,0.1);
}

.hero-content {
  max-width: 800px;
  padding: 0 20px;
}

.hero h1 {
  font-size: 42px;
  margin-bottom: 20px;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.hero p {
  font-size: 18px;
  margin-bottom: 30px;
}

.notice {
  background-color: var(--secondary-bg-color);
  padding: 15px;
  border-radius: 8px;
  margin: 30px 0;
  text-align: center;
  font-weight: 500;
  box-shadow: 0 4px 8px rgba(0,0,0,0.05);
}

.main-content {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 30px;
  margin-bottom: 60px;
}

.sidebar {
  background-color: white;
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  height: fit-content;
  position: sticky;
  top: 100px;
}

.sidebar-title {
  font-size: 18px;
  margin-bottom: 20px;
  color: var(--trust-color);
  padding-bottom: 10px;
  border-bottom: 2px solid var(--light-gray);
}

.sidebar-nav {
  list-style: none;
}

.sidebar-link {
  display: block;
  padding: 10px 0;
  color: var(--text-color);
  text-decoration: none;
  transition: all 0.3s ease;
  border-left: 3px solid transparent;
  padding-left: 10px;
}

.sidebar-link:hover {
  color: var(--accent-color);
  border-left: 3px solid var(--accent-color);
}

.article {
  background-color: white;
  border-radius: 12px;
  padding: 40px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}

.article h2 {
  font-size: 28px;
  margin-bottom: 20px;
  color: var(--trust-color);
  position: relative;
  padding-bottom: 10px;
}

.article h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
}

.article h3 {
  font-size: 22px;
  margin: 30px 0 15px;
  color: var(--dark-gray);
}

.article p {
  margin-bottom: 20px;
  font-size: 16px;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 20px;
  margin: 30px 0;
}

.image-card {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 8px 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 10px 20px rgba(0,0,0,0.15);
}

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

table {
  width: 100%;
  border-collapse: collapse;
  margin: 30px 0;
  box-shadow: 0 4px 12px rgba(0,0,0,0.08);
  border-radius: 12px;
  overflow: hidden;
}

thead {
  background: linear-gradient(90deg, var(--gradient-start), var(--gradient-end));
  color: white;
}

th {
  padding: 15px;
  text-align: left;
}

td {
  padding: 15px;
  background-color: white;
  border-bottom: 1px solid var(--light-gray);
}

pre {
  background-color: #f8f8f8;
  padding: 15px;
  border-radius: 8px;
  overflow-x: auto;
  font-family: 'Courier New', Courier, monospace;
  font-size: 14px;
  line-height: 1.5;
  margin: 15px 0;
  border-left: 4px solid var(--accent-color);
}

code {
  font-family: 'Courier New', Courier, monospace;
  background-color: #f8f8f8;
  padding: 2px 5px;
  border-radius: 3px;
  font-size: 14px;
}

.footer {
  background: linear-gradient(135deg, var(--gradient-start), var(--gradient-end));
  color: white;
  padding: 40px 0;
  text-align: center;
}

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

.footer p {
  margin-bottom: 20px;
}

@media (max-width: 768px) {
  .main-content {
    grid-template-columns: 1fr;
  }
  
  .sidebar {
    position: static;
    margin-bottom: 30px;
  }
  
  .hero h1 {
    font-size: 32px;
  }
  
  .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;
}