:root {
  --primary: #1E90FF;
  --secondary: #2c3e50;
  --accent: #FF8C00;
  --success: #28a745;
  --warning: #f44336;
  --light: #f5f5f5;
  --dark: #333;
  --text: #333;
  --white: #fff;
}

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

body {
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  color: var(--text);
  background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
  padding: 0;
  margin: 0;
}

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

.header {
  background: linear-gradient(135deg, var(--secondary) 0%, var(--primary) 100%);
  color: var(--white);
  padding: 2rem;
  text-align: center;
  border-radius: 0 0 20px 20px;
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
  margin-bottom: 3rem;
}

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

.header p {
  font-size: 1.2rem;
  opacity: 0.9;
}

.notice {
  background-color: rgba(255,255,255,0.9);
  color: var(--dark);
  padding: 1rem;
  text-align: center;
  border-radius: 8px;
  margin: 2rem auto;
  max-width: 800px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  font-size: 0.9rem;
}

.article-container {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 2rem;
  margin-bottom: 3rem;
}

article {
  background-color: var(--white);
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

article h2 {
  color: var(--primary);
  font-size: 1.8rem;
  margin-bottom: 1.5rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--light);
}

article h3 {
  color: var(--secondary);
  font-size: 1.5rem;
  margin: 2rem 0 1rem;
}

article p {
  margin-bottom: 1.5rem;
  font-size: 1.1rem;
  line-height: 1.7;
}

.sidebar {
  position: sticky;
  top: 20px;
  height: fit-content;
}

.nav-menu {
  background-color: var(--white);
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  margin-bottom: 2rem;
}

.nav-menu h3 {
  color: var(--primary);
  margin-bottom: 1rem;
  font-size: 1.2rem;
}

.nav-menu ul {
  list-style: none;
}

.nav-menu li {
  margin-bottom: 0.5rem;
}

.nav-menu a {
  color: var(--text);
  text-decoration: none;
  display: block;
  padding: 0.5rem 0;
  transition: all 0.3s ease;
}

.nav-menu a:hover {
  color: var(--primary);
  transform: translateX(5px);
}

.image-gallery {
  background-color: var(--white);
  padding: 1.5rem;
  border-radius: 12px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

.image-gallery h3 {
  color: var(--primary);
  margin-bottom: 1rem;
  font-size: 1.2rem;
}

.gallery-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1rem;
}

.gallery-item {
  border-radius: 8px;
  overflow: hidden;
  transition: all 0.3s ease;
  box-shadow: 0 3px 10px rgba(0,0,0,0.1);
}

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

.gallery-item img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.3s ease;
}

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

pre {
  background: #282c34;
  color: #abb2bf;
  padding: 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  margin: 1.5rem 0;
  font-size: 0.95rem;
  line-height: 1.5;
  box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

code {
  font-family: 'Fira Code', monospace;
}

.highlight {
  background-color: rgba(30, 144, 255, 0.1);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  color: var(--primary);
}

.footer {
  background: linear-gradient(135deg, var(--secondary) 0%, var(--primary) 100%);
  color: var(--white);
  text-align: center;
  padding: 2rem;
  border-radius: 20px 20px 0 0;
  margin-top: 3rem;
}

@media (max-width: 992px) {
  .article-container {
    grid-template-columns: 1fr;
  }
  
  .sidebar {
    position: static;
  }
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 2rem;
  }
  
  .gallery-grid {
    grid-template-columns: 1fr;
  }
  
  article {
    padding: 1.5rem;
  }
}

@media (max-width: 576px) {
  .header {
    padding: 1.5rem;
  }
  
  .header h1 {
    font-size: 1.8rem;
  }
  
  article h2 {
    font-size: 1.5rem;
  }
  
  article h3 {
    font-size: 1.3rem;
  }
}

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

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

/* Tooltip */
.tooltip {
  position: relative;
  display: inline-block;
  border-bottom: 1px dotted var(--primary);
}

.tooltip .tooltiptext {
  visibility: hidden;
  width: 200px;
  background-color: var(--dark);
  color: var(--white);
  text-align: center;
  border-radius: 6px;
  padding: 5px;
  position: absolute;
  z-index: 1;
  bottom: 125%;
  left: 50%;
  transform: translateX(-50%);
  opacity: 0;
  transition: opacity 0.3s;
}

.tooltip:hover .tooltiptext {
  visibility: visible;
  opacity: 1;
}