:root {
  --primary: #0d1b2a;
  --secondary: #1b263b;
  --accent: #00d2ff;
  --highlight: #3a7bd5;
  --text: #e0e1dd;
  --card-bg: rgba(255, 255, 255, 0.1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Montserrat', 'Open Sans', sans-serif;
}

body {
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  color: var(--text);
  line-height: 1.6;
  min-height: 100%;
  overflow-x: hidden;
}

.header {
  position: relative;
  height: 80vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 2rem;
  background: linear-gradient(rgba(13, 27, 42, 0.8), rgba(27, 38, 59, 0.8)), 
              url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
}

.header::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 100px;
  background: linear-gradient(to bottom, transparent, var(--primary));
}

.header h1 {
  font-size: 3.5rem;
  margin-bottom: 1.5rem;
  background: linear-gradient(45deg, var(--accent), var(--highlight));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 2px 10px rgba(0, 210, 255, 0.3);
}

.header p {
  font-size: 1.2rem;
  max-width: 800px;
  margin-bottom: 2rem;
}

.notice {
  position: fixed;
  top: 20px;
  right: 20px;
  background: var(--highlight);
  color: white;
  padding: 10px 20px;
  border-radius: 30px;
  font-size: 0.9rem;
  z-index: 1000;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(1); }
  50% { transform: scale(1.05); }
  100% { transform: scale(1); }
}

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

.article-container {
  background: rgba(27, 38, 59, 0.7);
  border-radius: 20px;
  padding: 3rem;
  margin: 3rem 0;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

article h2 {
  font-size: 2.2rem;
  margin: 2rem 0 1.5rem;
  color: var(--accent);
  position: relative;
  padding-bottom: 10px;
}

article h2::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100px;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--highlight));
}

article h3 {
  font-size: 1.8rem;
  margin: 1.8rem 0 1.2rem;
  color: var(--accent);
}

article p {
  font-size: 1.1rem;
  margin-bottom: 1.5rem;
  line-height: 1.8;
}

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

.image-card {
  position: relative;
  border-radius: 15px;
  overflow: hidden;
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.image-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.3);
}

.image-card img {
  width: 100%;
  height: 300px;
  object-fit: cover;
  display: block;
}

pre {
  background: rgba(0, 0, 0, 0.3);
  border-radius: 10px;
  padding: 1.5rem;
  margin: 2rem 0;
  overflow: auto;
  border-left: 4px solid var(--accent);
  font-family: 'Courier New', monospace;
  font-size: 0.95rem;
  line-height: 1.5;
}

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

.nav-tabs {
  display: flex;
  margin-bottom: 2rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-tab {
  padding: 0.8rem 1.5rem;
  margin-right: 0.5rem;
  background: transparent;
  border: none;
  color: var(--text);
  cursor: pointer;
  position: relative;
  font-size: 1rem;
  transition: all 0.3s ease;
}

.nav-tab.active {
  color: var(--accent);
}

.nav-tab.active::after {
  content: '';
  position: absolute;
  bottom: -1px;
  left: 0;
  width: 100%;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), var(--highlight));
}

.nav-tab:hover {
  color: var(--accent);
}

.footer {
  text-align: center;
  padding: 3rem 0;
  margin-top: 5rem;
  background: rgba(13, 27, 42, 0.8);
  position: relative;
}

.footer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
}

@media (max-width: 768px) {
  .header h1 {
    font-size: 2.5rem;
  }
  
  .article-container {
    padding: 2rem;
  }
  
  article h2 {
    font-size: 1.8rem;
  }
  
  article h3 {
    font-size: 1.5rem;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}