:root {
    --primary: #001f3f;
    --secondary: #33cccc;
    --accent: #ff9933;
    --text: #333;
    --light: #f8f9fa;
    --dark: #212529;
    --gradient: linear-gradient(-45deg, #001f3f, #6600ff, #33cccc, #ff9933);
    --shadow: 0 4px 20px rgba(0,0,0,0.1);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  }

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

  body {
    font-family: 'Montserrat', 'Open Sans', sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: var(--light);
    overflow-x: hidden;
  }

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

  /* Header Styles */
  .hero {
    position: relative;
    height: 600px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: var(--gradient);
    background-size: 400% 400%;
    animation: gradientAnimation 15s ease infinite;
    color: white;
    text-align: center;
    padding: 0 20px;
  }

  @keyframes gradientAnimation {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
  }

  .hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
  }

  .hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.3);
  }

  .hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
  }

  .hero-decoration {
    position: absolute;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
    opacity: 0.1;
    z-index: 1;
  }

  /* Navigation */
  .navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(0, 31, 63, 0);
    transition: var(--transition);
    padding: 20px 0;
    z-index: 1000;
    backdrop-filter: blur(5px);
  }

  .navbar.scrolled {
    background: rgba(0, 31, 63, 0.8);
    box-shadow: var(--shadow);
    padding: 15px 0;
  }

  .nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
  }

  .logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: white;
    text-decoration: none;
  }

  .nav-links {
    display: flex;
    gap: 30px;
  }

  .nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
  }

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

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

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

  /* Main Content */
  main {
    padding: 100px 0;
    background: white;
  }

  section {
    margin-bottom: 80px;
  }

  .section-header {
    text-align: center;
    margin-bottom: 50px;
  }

  .section-header h2 {
    font-size: 2.5rem;
    color: var(--primary);
    margin-bottom: 15px;
    position: relative;
    display: inline-block;
  }

  .section-header h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: var(--secondary);
  }

  .section-header p {
    max-width: 700px;
    margin: 0 auto;
    color: #666;
  }

  /* Article Styles */
  article {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 20px;
  }

  article h2 {
    font-size: 2rem;
    color: var(--primary);
    margin: 40px 0 20px;
    position: relative;
    padding-bottom: 10px;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: var(--accent);
  }

  article h3 {
    font-size: 1.5rem;
    color: var(--primary);
    margin: 30px 0 15px;
  }

  article p {
    margin-bottom: 20px;
    font-size: 1.1rem;
    line-height: 1.8;
  }

  /* Code Blocks */
  pre {
    background: #2d2d2d;
    border-radius: 8px;
    padding: 20px;
    margin: 25px 0;
    overflow: auto;
    box-shadow: var(--shadow);
  }

  code {
    font-family: 'Courier New', monospace;
    color: #f8f8f2;
    font-size: 0.9rem;
  }

  .language-css {
    display: block;
    white-space: pre;
  }

  /* Card Grid */
  .card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin: 50px 0;
  }

  .card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
  }

  .card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.15);
  }

  .card-img {
    height: 200px;
    overflow: hidden;
  }

  .card-img img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
  }

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

  .card-content {
    padding: 25px;
  }

  .card h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: var(--primary);
  }

  .card p {
    color: #666;
    margin-bottom: 20px;
  }

  /* Image Gallery */
  .gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin: 50px 0;
  }

  .gallery-item {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
  }

  .gallery-item:hover {
    transform: scale(1.03);
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
  }

  .gallery-item img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
  }

  /* Footer */
  footer {
    background: var(--dark);
    color: white;
    padding: 60px 0 30px;
    text-align: center;
  }

  .footer-content {
    max-width: 800px;
    margin: 0 auto;
  }

  .footer-logo {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: white;
  }

  .footer-links {
    display: flex;
    justify-content: center;
    gap: 30px;
    margin-bottom: 30px;
  }

  .footer-links a {
    color: #ccc;
    text-decoration: none;
    transition: var(--transition);
  }

  .footer-links a:hover {
    color: var(--accent);
  }

  .copyright {
    color: #999;
    font-size: 0.9rem;
  }

  /* Responsive */
  @media (max-width: 768px) {
    .hero {
      height: 500px;
    }

    .hero h1 {
      font-size: 2.2rem;
    }

    .hero p {
      font-size: 1rem;
    }

    .nav-links {
      gap: 15px;
    }

    .section-header h2 {
      font-size: 2rem;
    }

    article h2 {
      font-size: 1.7rem;
    }

    article h3 {
      font-size: 1.3rem;
    }

    .card-grid {
      grid-template-columns: 1fr;
    }
  }

  @media (max-width: 480px) {
    .hero {
      height: 400px;
    }

    .hero h1 {
      font-size: 1.8rem;
    }

    .nav-container {
      flex-direction: column;
      gap: 15px;
    }

    .nav-links {
      flex-wrap: wrap;
      justify-content: center;
    }

    .section-header h2 {
      font-size: 1.7rem;
    }
  }

  /* Utility Classes */
  .btn {
    display: inline-block;
    padding: 12px 30px;
    background: var(--secondary);
    color: white;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(51, 204, 204, 0.3);
  }

  .btn:hover {
    background: var(--accent);
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(255, 153, 51, 0.4);
  }

  .text-center {
    text-align: center;
  }

  .mb-30 {
    margin-bottom: 30px;
  }

  .note {
    background: rgba(51, 204, 204, 0.1);
    border-left: 4px solid var(--secondary);
    padding: 20px;
    margin: 30px 0;
    border-radius: 0 8px 8px 0;
  }

  .note p {
    margin: 0;
  }

  /* Floating Elements */
  .floating {
    animation: floating 3s ease-in-out infinite;
  }

  @keyframes floating {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-15px); }
    100% { transform: translateY(0px); }
  }

  /* Decorative Elements */
  .decor-circle {
    position: absolute;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.1);
    z-index: 0;
  }

  .circle-1 {
    width: 300px;
    height: 300px;
    top: -150px;
    right: -150px;
    background: radial-gradient(circle, rgba(102, 0, 255, 0.2) 0%, transparent 70%);
  }

  .circle-2 {
    width: 200px;
    height: 200px;
    bottom: -100px;
    left: -100px;
    background: radial-gradient(circle, rgba(255, 153, 51, 0.2) 0%, transparent 70%);
  }