:root {
  --primary-color: #0D47A1;
  --accent-color: #FF9800;
  --neutral-gray: #9E9E9E;
  --background-color: #FFFFFF;
  --dark-bg: #121212;
  --light-text: #E0E0E0;
  --shadow-color: rgba(0,0,0,0.2);
}

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

body {
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  color: var(--neutral-gray);
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
  min-height: 100%;
  overflow-x: hidden;
}

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

.header {
  background: linear-gradient(90deg, var(--primary-color) 0%, #1565C0 100%);
  color: white;
  padding: 2rem 0;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 12px var(--shadow-color);
}

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

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 0;
  position: relative;
  z-index: 1;
}

.logo {
  font-size: 1.8rem;
  font-weight: 700;
  color: white;
  text-decoration: none;
  font-family: 'Montserrat', sans-serif;
}

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

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

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

.hero {
  text-align: center;
  padding: 4rem 0;
  position: relative;
  z-index: 1;
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: 1.5rem;
  color: white;
  font-family: 'Montserrat', sans-serif;
  text-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.hero p {
  font-size: 1.2rem;
  max-width: 700px;
  margin: 0 auto 2rem;
  color: rgba(255,255,255,0.9);
}

.notice {
  background: rgba(255,255,255,0.2);
  backdrop-filter: blur(10px);
  padding: 1rem;
  border-radius: 8px;
  display: inline-block;
  margin-top: 2rem;
  border: 1px solid rgba(255,255,255,0.3);
}

.notice p {
  color: white;
  margin: 0;
  font-weight: 500;
}

.main-content {
  padding: 4rem 0;
}

.section {
  margin-bottom: 4rem;
  background: white;
  border-radius: 12px;
  padding: 2.5rem;
  box-shadow: 0 8px 24px rgba(0,0,0,0.08);
  position: relative;
  overflow: hidden;
}

.section::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: linear-gradient(to bottom, var(--primary-color), var(--accent-color));
}

.section h2 {
  font-family: 'Montserrat', sans-serif;
  color: var(--primary-color);
  margin-bottom: 1.5rem;
  font-size: 2rem;
  position: relative;
  padding-bottom: 0.5rem;
}

.section h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: var(--accent-color);
}

.section h3 {
  font-family: 'Montserrat', sans-serif;
  color: var(--accent-color);
  margin: 1.5rem 0 1rem;
  font-size: 1.5rem;
}

.section p {
  margin-bottom: 1.5rem;
  font-size: 1.1rem;
  line-height: 1.8;
}

.section strong {
  color: var(--primary-color);
}

.section em {
  color: var(--accent-color);
  font-style: normal;
  font-weight: 500;
}

.code-container {
  background: #f8f9fa;
  border-radius: 8px;
  padding: 1.5rem;
  margin: 1.5rem 0;
  border-left: 4px solid var(--accent-color);
  overflow: auto;
}

pre {
  margin: 0;
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.95rem;
  color: #333;
  white-space: pre-wrap;
}

code {
  font-family: 'Courier New', Courier, monospace;
  background: rgba(13, 71, 161, 0.1);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  color: var(--primary-color);
  font-size: 0.95rem;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  border-radius: 8px;
  overflow: hidden;
}

th, td {
  padding: 1rem;
  text-align: left;
  border-bottom: 1px solid #eee;
}

th {
  background: var(--primary-color);
  color: white;
  font-weight: 500;
}

tr:nth-child(even) {
  background: #f9f9f9;
}

tr:hover {
  background: rgba(255, 152, 0, 0.05);
}

ol, ul {
  margin: 1.5rem 0;
  padding-left: 2rem;
}

li {
  margin-bottom: 0.5rem;
}

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

.image-card {
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 12px var(--shadow-color);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  position: relative;
}

.image-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.15);
}

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

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

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

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

.social-links a {
  color: white;
  font-size: 1.5rem;
  transition: color 0.3s ease;
}

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

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .hero h1 {
    font-size: 2.2rem;
  }
  
  .section {
    padding: 1.5rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

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

.section {
  animation: fadeIn 0.6s ease-out forwards;
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }
.delay-4 { animation-delay: 0.4s; }