:root {
  --primary-color: #0d47a1;
  --accent-color: #00bcd4;
  --highlight-color: #76ff03;
  --background-color: #121212;
  --text-color: #ffffff;
  --card-bg: rgba(255, 255, 255, 0.05);
  --section-padding: 80px;
}

body {
  background: var(--background-color);
  color: var(--text-color);
  font-family: 'Roboto', sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 0;
  transition: all 0.5s ease;
}

.header {
  background: linear-gradient(135deg, var(--primary-color), #000);
  padding: 40px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.header::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
  opacity: 0.2;
  z-index: 0;
}

.header-content {
  position: relative;
  z-index: 1;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

h1 {
  font-size: 3rem;
  margin: 0;
  background: linear-gradient(to right, var(--accent-color), var(--highlight-color));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-shadow: 0 0 10px rgba(0, 188, 212, 0.3);
}

.tagline {
  font-size: 1.2rem;
  margin: 20px 0 0;
  color: rgba(255, 255, 255, 0.8);
}

.note {
  background: rgba(255, 255, 255, 0.1);
  padding: 15px;
  border-radius: 8px;
  margin: 30px auto;
  max-width: 800px;
  text-align: center;
  border-left: 4px solid var(--highlight-color);
  font-size: 0.9rem;
}

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

article {
  margin: 60px 0;
}

h2 {
  font-size: 2.2rem;
  color: var(--accent-color);
  margin: 50px 0 20px;
  position: relative;
  padding-bottom: 15px;
}

h2::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100px;
  height: 3px;
  background: linear-gradient(to right, var(--accent-color), var(--highlight-color));
}

h3 {
  font-size: 1.8rem;
  color: var(--highlight-color);
  margin: 40px 0 15px;
}

p {
  font-size: 1.1rem;
  margin: 0 0 25px;
  color: rgba(255, 255, 255, 0.9);
}

strong {
  color: var(--highlight-color);
}

pre {
  background: rgba(0, 0, 0, 0.3);
  border-radius: 8px;
  padding: 20px;
  overflow-x: auto;
  margin: 30px 0;
  border-left: 4px solid var(--accent-color);
  box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

code {
  font-family: 'Courier New', monospace;
  color: var(--highlight-color);
  background: transparent;
  padding: 0;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 30px;
  margin: 40px 0;
}

.image-card {
  background: var(--card-bg);
  border-radius: 12px;
  overflow: hidden;
  transition: all 0.3s ease;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
}

.image-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 30px rgba(0, 188, 212, 0.3);
}

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

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

.nav-tabs {
  position: sticky;
  top: 0;
  background: rgba(18, 18, 18, 0.9);
  backdrop-filter: blur(10px);
  z-index: 1000;
  padding: 15px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.nav-tabs ul {
  display: flex;
  justify-content: center;
  list-style: none;
  padding: 0;
  margin: 0;
  gap: 30px;
}

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

.nav-tabs a:hover {
  color: var(--highlight-color);
  background: rgba(255, 255, 255, 0.1);
}

.nav-tabs a::after {
  content: "";
  position: absolute;
  bottom: -5px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--highlight-color);
  transition: width 0.3s ease;
}

.nav-tabs a:hover::after {
  width: 80%;
}

.footer {
  background: linear-gradient(to right, var(--primary-color), #000);
  padding: 40px 0;
  text-align: center;
  margin-top: 80px;
}

.footer p {
  color: rgba(255, 255, 255, 0.7);
  margin: 0;
}

@media (max-width: 768px) {
  h1 {
    font-size: 2.2rem;
  }
  
  h2 {
    font-size: 1.8rem;
  }
  
  h3 {
    font-size: 1.5rem;
  }
  
  .nav-tabs ul {
    flex-wrap: wrap;
    gap: 15px;
  }
  
  .image-grid {
    grid-template-columns: 1fr;
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-20px);
  }
}

.floating {
  animation: float 6s ease-in-out infinite;
}