:root {
  --primary-color: #0d47a1;
  --accent-color: #00e676;
  --secondary-color: #2979ff;
  --background-gradient: linear-gradient(135deg, #0d47a1, #6a1b9a);
  --card-bg: #1e2733;
  --text-color: #ffffff;
  --border-radius: 8px;
  --box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
  --transition: all 0.3s ease;
}

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

body {
  background: var(--background-gradient);
  color: var(--text-color);
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  padding: 0;
  margin: 0;
  min-height: 100%;
}

.header {
  text-align: center;
  padding: 2rem 0;
  position: relative;
  overflow: hidden;
}

.header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(135deg, rgba(13,71,161,0.8), rgba(106,27,154,0.8));
  z-index: -1;
}

.header h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  background: linear-gradient(90deg, var(--accent-color), var(--secondary-color));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 2px 4px rgba(0,0,0,0.2);
}

.notice {
  background: rgba(0,0,0,0.2);
  padding: 0.5rem;
  border-radius: var(--border-radius);
  font-size: 0.9rem;
  margin: 1rem auto;
  max-width: 800px;
  text-align: center;
  border: 1px solid var(--accent-color);
}

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

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

.card {
  background: var(--card-bg);
  border-radius: var(--border-radius);
  box-shadow: var(--box-shadow);
  transition: var(--transition);
  overflow: hidden;
  position: relative;
}

.card:hover {
  transform: translateY(-10px);
  box-shadow: 0 12px 20px rgba(0, 0, 0, 0.2);
}

.card-img {
  width: 100%;
  height: 200px;
  object-fit: cover;
  border-radius: var(--border-radius) var(--border-radius) 0 0;
  transition: var(--transition);
}

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

.card-content {
  padding: 1.5rem;
}

.card-title {
  font-size: 1.2rem;
  margin-bottom: 1rem;
  color: var(--accent-color);
}

.card-text {
  margin-bottom: 1.5rem;
  font-size: 0.95rem;
}

.article-container {
  background: rgba(30,39,51,0.8);
  border-radius: var(--border-radius);
  padding: 2rem;
  margin: 2rem 0;
  box-shadow: var(--box-shadow);
}

article h2 {
  font-size: 1.8rem;
  margin: 2rem 0 1rem;
  color: var(--accent-color);
  position: relative;
  padding-left: 1rem;
}

article h2::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  height: 100%;
  width: 4px;
  background: var(--accent-color);
  border-radius: 2px;
}

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

pre {
  background: rgba(0,0,0,0.3);
  border-radius: var(--border-radius);
  padding: 1rem;
  margin: 1.5rem 0;
  overflow-x: auto;
  border-left: 3px solid var(--accent-color);
}

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

.nav-tabs {
  display: flex;
  justify-content: center;
  margin: 2rem 0;
  flex-wrap: wrap;
}

.nav-tabs a {
  color: var(--text-color);
  text-decoration: none;
  padding: 0.5rem 1rem;
  margin: 0 0.5rem;
  border-radius: var(--border-radius);
  transition: var(--transition);
  border: 1px solid transparent;
}

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

.footer {
  text-align: center;
  padding: 2rem;
  margin-top: 3rem;
  background: rgba(0,0,0,0.2);
  border-radius: var(--border-radius);
}

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

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

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