:root {
  --primary: #0074D9;
  --secondary: #001f3f;
  --accent: #FF851B;
  --highlight: #2ECC40;
  --text: #FFFFFF;
  --bg-gradient: linear-gradient(135deg, var(--secondary), var(--primary));
}

body {
  margin: 0;
  padding: 0;
  font-family: 'Roboto', 'Helvetica', sans-serif;
  background: var(--bg-gradient);
  color: var(--text);
  line-height: 1.6;
}

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

.header {
  text-align: center;
  padding: 60px 0;
  position: relative;
}

.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: -1;
  border-radius: 20px;
}

h1, h2, h3, h4 {
  font-weight: 600;
  margin-top: 2rem;
}

h1 {
  font-size: 2.5rem;
  background: linear-gradient(90deg, var(--accent), var(--highlight));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  margin-bottom: 1.5rem;
}

h2 {
  font-size: 2rem;
  border-bottom: 3px solid var(--accent);
  padding-bottom: 10px;
  display: inline-block;
}

h3 {
  font-size: 1.5rem;
  color: var(--highlight);
}

.article-content {
  background: rgba(0, 31, 63, 0.7);
  padding: 40px;
  border-radius: 20px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
  margin-bottom: 40px;
}

.code-block {
  background: rgba(0, 0, 0, 0.3);
  border-left: 4px solid var(--accent);
  padding: 20px;
  border-radius: 5px;
  overflow-x: auto;
  margin: 20px 0;
  font-family: 'Courier New', monospace;
  font-size: 0.9rem;
}

.code-block pre {
  margin: 0;
}

.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  margin: 40px 0;
}

.image-card {
  background: rgba(255, 255, 255, 0.1);
  border-radius: 15px;
  overflow: hidden;
  transition: transform 0.3s, box-shadow 0.3s;
}

.image-card:hover {
  transform: translateY(-10px);
  box-shadow: 0 15px 30px rgba(0, 0, 0, 0.4);
}

.image-card img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: 15px 15px 0 0;
}

.image-caption {
  padding: 15px;
  text-align: center;
}

.note {
  background: rgba(255, 133, 27, 0.2);
  border-left: 4px solid var(--accent);
  padding: 15px;
  margin: 20px 0;
  border-radius: 0 5px 5px 0;
}

@media (max-width: 768px) {
  .container {
    padding: 10px;
  }
  
  .article-content {
    padding: 20px;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  h3 {
    font-size: 1.2rem;
  }
}

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

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

.decorative-line {
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--accent), transparent);
  margin: 40px 0;
  border: none;
}

.navbar {
  position: sticky;
  top: 0;
  background: rgba(0, 31, 63, 0.9);
  backdrop-filter: blur(10px);
  padding: 15px 0;
  z-index: 100;
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.nav-logo {
  font-size: 1.5rem;
  font-weight: bold;
  color: var(--text);
  text-decoration: none;
}

.nav-links {
  display: flex;
  list-style: none;
  gap: 20px;
}

.nav-links a {
  color: var(--text);
  text-decoration: none;
  transition: color 0.3s;
  position: relative;
}

.nav-links a:hover {
  color: var(--highlight);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -5px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--highlight);
  transition: width 0.3s;
}

.nav-links a:hover::after {
  width: 100%;
}

.footer {
  text-align: center;
  padding: 30px 0;
  margin-top: 60px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.reference-note {
  background: rgba(255, 255, 255, 0.1);
  padding: 15px;
  border-radius: 10px;
  text-align: center;
  margin: 40px 0;
  font-style: italic;
}

.color-swatch {
  display: inline-block;
  width: 20px;
  height: 20px;
  border-radius: 50%;
  margin-right: 5px;
  vertical-align: middle;
}