:root {
  --primary: #0E1E3D;
  --secondary: #1B2735;
  --accent: #4CAF50;
  --warning: #FF9800;
  --text: #FFFFFF;
  --card-bg: rgba(255, 255, 255, 0.1);
  --transition: all 0.3s ease;
}

body {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: var(--text);
  font-family: 'Open Sans', sans-serif;
  line-height: 1.6;
  letter-spacing: 0.5px;
  margin: 0;
  padding: 0;
  min-height: 100%;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 100px 20px 50px;
}

.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(14, 30, 61, 0.95);
  backdrop-filter: blur(10px);
  z-index: 1000;
  padding: 15px 0;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.2);
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 30px;
}

.logo {
  font-family: 'Roboto', sans-serif;
  font-weight: 500;
  font-size: 1.5rem;
  color: var(--text);
  text-decoration: none;
}

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

.nav-links a {
  color: var(--text);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
  position: relative;
}

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

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

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

.hero {
  text-align: center;
  padding: 60px 0;
  margin-bottom: 60px;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: radial-gradient(circle at center, rgba(76, 175, 80, 0.1), transparent 70%);
  z-index: -1;
}

.hero h1 {
  font-size: 3rem;
  margin-bottom: 20px;
  background: linear-gradient(90deg, #FFFFFF, #4CAF50);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero p {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 0 auto 30px;
}

.notice {
  background: rgba(255, 152, 0, 0.2);
  border-left: 4px solid var(--warning);
  padding: 15px;
  margin: 30px 0;
  border-radius: 0 8px 8px 0;
}

.notice p {
  margin: 0;
  color: var(--text);
}

article {
  background: var(--card-bg);
  border-radius: 15px;
  padding: 40px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  margin-bottom: 60px;
}

article h2 {
  font-family: 'Roboto', sans-serif;
  font-weight: 500;
  font-size: 2rem;
  margin-top: 0;
  color: var(--text);
  position: relative;
  padding-bottom: 15px;
}

article h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100px;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), transparent);
}

article h3 {
  font-family: 'Roboto', sans-serif;
  font-weight: 500;
  font-size: 1.5rem;
  margin: 30px 0 15px;
  color: var(--text);
}

article p {
  margin-bottom: 20px;
  font-size: 1.1rem;
}

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

.image-item {
  border-radius: 10px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
  transition: var(--transition);
  position: relative;
}

.image-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.3);
}

.image-item img {
  width: 100%;
  height: auto;
  display: block;
  transition: var(--transition);
}

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

pre {
  background: rgba(0, 0, 0, 0.3);
  border-radius: 8px;
  padding: 20px;
  overflow-x: auto;
  margin: 30px 0;
  border-left: 4px solid var(--accent);
}

code {
  font-family: 'Courier New', monospace;
  color: var(--text);
}

.footer {
  background: rgba(14, 30, 61, 0.95);
  padding: 40px 0;
  text-align: center;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
  padding: 0 20px;
}

.footer-section h3 {
  font-family: 'Roboto', sans-serif;
  font-weight: 500;
  margin-bottom: 20px;
  color: var(--text);
}

.footer-links {
  list-style: none;
  padding: 0;
}

.footer-links li {
  margin-bottom: 10px;
}

.footer-links a {
  color: var(--text);
  text-decoration: none;
  transition: var(--transition);
}

.footer-links a:hover {
  color: var(--accent);
  padding-left: 5px;
}

.copyright {
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.7);
}

@media (max-width: 768px) {
  .navbar {
    flex-direction: column;
    padding: 15px;
  }
  
  .nav-links {
    margin-top: 20px;
    flex-direction: column;
    gap: 15px;
    align-items: center;
  }
  
  .hero h1 {
    font-size: 2rem;
  }
  
  article {
    padding: 30px 20px;
  }
  
  .footer-content {
    grid-template-columns: 1fr;
  }
}

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

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

.toc {
  background: var(--card-bg);
  border-radius: 10px;
  padding: 20px;
  margin-bottom: 40px;
}

.toc h3 {
  margin-top: 0;
  color: var(--text);
}

.toc ul {
  list-style: none;
  padding: 0;
}

.toc li {
  margin-bottom: 10px;
  position: relative;
  padding-left: 20px;
}

.toc li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 8px;
  height: 8px;
  background: var(--accent);
  border-radius: 50%;
}

.toc a {
  color: var(--text);
  text-decoration: none;
  transition: var(--transition);
}

.toc a:hover {
  color: var(--accent);
  padding-left: 5px;
}

.expandable {
  background: rgba(0, 0, 0, 0.2);
  border-radius: 8px;
  padding: 15px;
  margin: 20px 0;
  cursor: pointer;
  transition: var(--transition);
}

.expandable:hover {
  background: rgba(0, 0, 0, 0.3);
}

.expandable-title {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-weight: bold;
}

.expandable-content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease;
}

.expandable.active .expandable-content {
  max-height: 1000px;
  margin-top: 15px;
}

.expandable-arrow {
  transition: transform 0.3s ease;
}

.expandable.active .expandable-arrow {
  transform: rotate(180deg);
}