:root {
  --primary-color: #1E90FF;
  --secondary-color: #00BFFF;
  --background-color: #FFFFFF;
  --gray-light: #F0F0F0;
  --gray-dark: #A9A9A9;
  --accent-orange: #FFA500;
  --accent-green: #32CD32;
  --text-primary: #333333;
  --text-secondary: #666666;
}

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

body {
  background-color: var(--background-color);
  color: var(--text-primary);
  line-height: 1.6;
  padding: 0;
  margin: 0;
  min-height: 100%;
  overflow-x: hidden;
}

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

.header {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: var(--background-color);
  padding: 40px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--accent-orange), var(--accent-green));
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 10px;
  font-weight: 700;
  text-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

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

.notice {
  background-color: rgba(255, 255, 255, 0.2);
  padding: 15px;
  border-radius: 8px;
  margin: 20px auto;
  max-width: 800px;
  backdrop-filter: blur(5px);
  border: 1px solid rgba(255, 255, 255, 0.3);
}

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

.main-content {
  display: grid;
  grid-template-columns: 250px 1fr;
  gap: 30px;
  padding: 40px 0;
}

@media (max-width: 768px) {
  .main-content {
    grid-template-columns: 1fr;
  }
}

.sidebar {
  background: var(--gray-light);
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
  height: fit-content;
  position: sticky;
  top: 20px;
}

.sidebar h3 {
  color: var(--primary-color);
  margin-bottom: 20px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--secondary-color);
}

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

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

.nav-links a {
  display: block;
  padding: 10px 15px;
  color: var(--text-primary);
  text-decoration: none;
  border-radius: 6px;
  transition: all 0.3s ease;
  font-weight: 500;
}

.nav-links a:hover {
  background-color: rgba(30, 144, 255, 0.1);
  color: var(--primary-color);
  transform: translateX(5px);
}

.nav-links a.active {
  background-color: var(--primary-color);
  color: white;
}

.content-area {
  background: var(--background-color);
  border-radius: 12px;
  padding: 30px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
}

article {
  max-width: 800px;
  margin: 0 auto;
}

article h2 {
  color: var(--primary-color);
  font-size: 1.8rem;
  margin: 30px 0 20px;
  padding-bottom: 10px;
  border-bottom: 2px solid var(--gray-light);
}

article h3 {
  color: var(--secondary-color);
  font-size: 1.4rem;
  margin: 25px 0 15px;
}

article p {
  margin-bottom: 20px;
  color: var(--text-primary);
  font-size: 1.05rem;
}

color {
  font-weight: bold;
  color: var(--primary-color);
}

pre {
  background-color: #f8f9fa;
  border-radius: 8px;
  padding: 20px;
  overflow: auto;
  margin: 20px 0;
  border-left: 4px solid var(--primary-color);
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.1);
}

code {
  font-family: 'Courier New', Courier, monospace;
  font-size: 0.9rem;
  color: #333;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin: 25px 0;
  box-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
  border-radius: 8px;
  overflow: hidden;
}

th {
  background-color: var(--primary-color);
  color: white;
  padding: 15px;
  text-align: left;
}

td {
  padding: 15px;
  border-bottom: 1px solid var(--gray-light);
  vertical-align: top;
}

tr:nth-child(even) {
  background-color: var(--gray-light);
}

tr:hover {
  background-color: rgba(30, 144, 255, 0.05);
}

.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 5px 15px 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 25px rgba(0, 0, 0, 0.15);
}

.image-card img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 12px;
}

.footer {
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: var(--background-color);
  padding: 30px 0;
  text-align: center;
  margin-top: 60px;
}

.footer p {
  opacity: 0.8;
  margin-bottom: 10px;
}

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

.animate-fade {
  animation: fadeIn 0.8s ease forwards;
}

.delay-1 { animation-delay: 0.2s; }
.delay-2 { animation-delay: 0.4s; }
.delay-3 { animation-delay: 0.6s; }

/* Responsive adjustments */
@media (max-width: 992px) {
  .header h1 {
    font-size: 2rem;
  }
  
  .header p {
    font-size: 1rem;
  }
}

@media (max-width: 768px) {
  .main-content {
    padding: 20px 0;
  }
  
  .content-area {
    padding: 20px;
  }
  
  article h2 {
    font-size: 1.6rem;
  }
  
  article h3 {
    font-size: 1.3rem;
  }
}

@media (max-width: 576px) {
  .header {
    padding: 30px 0;
  }
  
  .header h1 {
    font-size: 1.8rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}