:root {
  --primary: #1E90FF;
  --secondary: #FF8C00;
  --accent: #32CD32;
  --bg-main: #F5F7FA;
  --bg-card: #FFFFFF;
  --text-main: #333333;
  --text-light: #666666;
}

body {
  font-family: 'Roboto', 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-main);
  background: var(--bg-main);
  margin: 0;
  padding: 0;
  background-image: 
    radial-gradient(circle at 10% 20%, rgba(30, 144, 255, 0.03) 0%, transparent 20%),
    radial-gradient(circle at 90% 80%, rgba(255, 140, 0, 0.03) 0%, transparent 20%);
}

.header {
  background: linear-gradient(135deg, var(--primary), #0D47A1);
  color: white;
  padding: 2rem 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

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

.header h1 {
  font-size: 2.5rem;
  margin: 0;
  font-weight: 700;
  text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.header p {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 1rem auto;
  opacity: 0.9;
}

.notice {
  background: rgba(255,255,255,0.2);
  padding: 1rem;
  border-radius: 8px;
  display: inline-block;
  margin-top: 1rem;
  backdrop-filter: blur(5px);
}

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

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

.card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 2rem;
  box-shadow: 0 10px 20px rgba(0,0,0,0.08);
  transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  position: relative;
  overflow: hidden;
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 30px rgba(0,0,0,0.12);
}

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

.card-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: 8px;
  margin-bottom: 1.5rem;
  box-shadow: 0 4px 8px rgba(0,0,0,0.1);
  transition: transform 0.3s ease;
}

.card:hover .card-img {
  transform: scale(1.02);
}

h2, h3, h4 {
  color: var(--primary);
  margin-top: 2rem;
  position: relative;
}

h2 {
  font-size: 1.8rem;
  padding-bottom: 0.5rem;
}

h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 60px;
  height: 3px;
  background: linear-gradient(90deg, var(--primary), var(--secondary));
}

h3 {
  font-size: 1.5rem;
}

article {
  background: var(--bg-card);
  padding: 2rem;
  border-radius: 12px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  margin-bottom: 3rem;
}

pre {
  background: #282C34;
  color: #ABB2BF;
  padding: 1.5rem;
  border-radius: 8px;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
  line-height: 1.5;
  margin: 1.5rem 0;
  box-shadow: inset 0 0 10px rgba(0,0,0,0.3);
}

code {
  font-family: 'Courier New', monospace;
  background: rgba(30, 144, 255, 0.1);
  padding: 0.2rem 0.4rem;
  border-radius: 4px;
  color: var(--primary);
}

.nav-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin: 2rem 0;
}

.nav-tabs a {
  background: rgba(30, 144, 255, 0.1);
  color: var(--primary);
  padding: 0.8rem 1.5rem;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 500;
  transition: all 0.3s ease;
}

.nav-tabs a:hover {
  background: var(--primary);
  color: white;
  transform: translateY(-2px);
}

.footer {
  text-align: center;
  padding: 2rem;
  color: var(--text-light);
  font-size: 0.9rem;
}

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

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

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