:root {
  --primary-color: #12263F;
  --secondary-color: #5BC0EB;
  --accent-color: #E8EAF6;
  --background-color: #FFFFFF;
  --font-family: 'Roboto', sans-serif;
  --border-radius: 12px;
  --box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}

body {
  font-family: var(--font-family);
  line-height: 1.6;
  color: var(--primary-color);
  background: linear-gradient(135deg, #f5f7fa 0%, #e8eaf6 100%);
  margin: 0;
  padding: 0;
  min-height: 100%;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

.header {
  text-align: center;
  margin-bottom: 3rem;
  position: relative;
  padding: 2rem 0;
}

.header::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 25%;
  width: 50%;
  height: 3px;
  background: linear-gradient(90deg, var(--secondary-color), var(--primary-color));
  border-radius: 3px;
}

h1, h2, h3, h4 {
  color: var(--primary-color);
  margin-top: 2rem;
  font-weight: 700;
}

h1 {
  font-size: 2.5rem;
  background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 1rem;
}

h2 {
  font-size: 1.8rem;
  border-left: 5px solid var(--secondary-color);
  padding-left: 1rem;
  margin-bottom: 1.5rem;
}

h3 {
  font-size: 1.5rem;
  margin-bottom: 1rem;
}

p {
  font-size: 1.1rem;
  margin-bottom: 1.5rem;
  color: #444;
}

.article-wrapper {
  background: white;
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  padding: 3rem;
  margin-bottom: 3rem;
}

.code-container {
  background: #2d3748;
  border-radius: var(--border-radius);
  padding: 1.5rem;
  margin: 2rem 0;
  position: relative;
  overflow: hidden;
}

.code-container::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 40px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--border-radius) var(--border-radius) 0 0;
}

code {
  font-family: 'Fira Code', monospace;
  color: #e2e8f0;
  font-size: 0.9rem;
  line-height: 1.6;
}

pre {
  margin: 0;
  white-space: pre-wrap;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 2rem;
  margin: 3rem 0;
}

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

.image-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.15);
}

.image-card img {
  width: 100%;
  height: auto;
  display: block;
  transition: transform 0.5s ease;
}

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

.notice {
  background: rgba(91, 192, 235, 0.1);
  border-left: 4px solid var(--secondary-color);
  padding: 1.5rem;
  margin: 2rem 0;
  border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.nav-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2rem;
  justify-content: center;
}

.nav-tab {
  padding: 0.8rem 1.5rem;
  background: white;
  border-radius: 50px;
  cursor: pointer;
  font-weight: 600;
  transition: all 0.3s ease;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
  color: var(--primary-color);
}

.nav-tab:hover {
  background: var(--secondary-color);
  color: white;
  transform: translateY(-2px);
}

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

@media (max-width: 768px) {
  .container {
    padding: 1.5rem;
  }
  
  .article-wrapper {
    padding: 2rem;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.6rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

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

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