:root {
    --primary-dark: #1e3c72;
    --primary-light: #2a5298;
    --accent: #6a11cb;
    --highlight: #2575fc;
    --text-light: #ffffff;
    --text-dark: #333333;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  }

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

  body {
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8f0 100%);
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
  }

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

  /* Header Styles */
  header {
    background: rgba(30, 60, 114, 0.95);
    position: fixed;
    width: 100%;
    z-index: 1000;
    box-shadow: var(--shadow);
    backdrop-filter: blur(10px);
  }

  .navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 0;
  }

  .logo {
    color: var(--text-light);
    font-size: 1.8rem;
    font-weight: 700;
    text-decoration: none;
    display: flex;
    align-items: center;
  }

  .logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(45deg, var(--highlight), var(--accent));
    border-radius: 50%;
    margin-right: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
  }

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

  .nav-links li {
    margin-left: 30px;
  }

  .nav-links a {
    color: var(--text-light);
    text-decoration: none;
    font-weight: 500;
    font-size: 1.1rem;
    transition: var(--transition);
    position: relative;
  }

  .nav-links a:hover {
    color: #ffd700;
  }

  .nav-links a::after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: -5px;
    left: 0;
    background: #ffd700;
    transition: var(--transition);
  }

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

  /* Hero Section */
  .hero {
    padding: 180px 0 100px;
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-light));
    position: relative;
    overflow: hidden;
  }

  .hero::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: 0.15;
    z-index: 0;
  }

  .hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: var(--text-light);
    max-width: 800px;
    margin: 0 auto;
  }

  .hero h1 {
    font-size: 3.5rem;
    margin-bottom: 20px;
    line-height: 1.2;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.3);
  }

  .hero p {
    font-size: 1.3rem;
    margin-bottom: 40px;
    opacity: 0.9;
  }

  .cta-button {
    display: inline-block;
    background: linear-gradient(45deg, var(--highlight), var(--accent));
    color: var(--text-light);
    padding: 15px 40px;
    border-radius: 50px;
    font-weight: 600;
    text-decoration: none;
    font-size: 1.1rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    transition: var(--transition);
    border: none;
    cursor: pointer;
  }

  .cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.3);
  }

  /* Main Content */
  .main-content {
    padding: 80px 0;
  }

  .section {
    margin-bottom: 80px;
    background: var(--text-light);
    border-radius: 15px;
    padding: 50px;
    box-shadow: var(--shadow);
    position: relative;
    overflow: hidden;
  }

  .section::after {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 200px;
    height: 200px;
    background: linear-gradient(45deg, rgba(106, 17, 203, 0.1), rgba(37, 117, 252, 0.1));
    border-radius: 50%;
    transform: translate(50px, -50px);
  }

  .section-title {
    font-size: 2.5rem;
    margin-bottom: 30px;
    color: var(--primary-dark);
    position: relative;
    display: inline-block;
  }

  .section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 0;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--highlight), var(--accent));
    border-radius: 2px;
  }

  .article-content {
    font-size: 1.1rem;
    line-height: 1.8;
  }

  .article-content p {
    margin-bottom: 25px;
  }

  .article-content h2, 
  .article-content h3 {
    margin: 40px 0 20px;
    color: var(--primary-dark);
  }

  .article-content h2 {
    font-size: 2rem;
  }

  .article-content h3 {
    font-size: 1.6rem;
  }

  /* Code Blocks */
  pre {
    background: #282c34;
    border-radius: 8px;
    padding: 20px;
    margin: 30px 0;
    overflow: auto;
    box-shadow: var(--shadow);
  }

  code {
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    color: #abb2bf;
  }

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

  /* Image Gallery */
  .image-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin: 40px 0;
  }

  .gallery-item {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    height: 300px;
  }

  .gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  }

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

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

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

  .feature-card {
    background: var(--text-light);
    border-radius: 15px;
    padding: 30px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
  }

  .feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(to bottom, var(--highlight), var(--accent));
  }

  .feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.15);
  }

  .feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(45deg, var(--highlight), var(--accent));
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    color: var(--text-light);
    font-size: 1.5rem;
  }

  .feature-card h3 {
    font-size: 1.4rem;
    margin-bottom: 15px;
    color: var(--primary-dark);
  }

  /* Footer */
  footer {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-light));
    color: var(--text-light);
    padding: 60px 0 30px;
  }

  .footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
  }

  .footer-column h4 {
    font-size: 1.3rem;
    margin-bottom: 20px;
    position: relative;
    display: inline-block;
  }

  .footer-column h4::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 40px;
    height: 3px;
    background: #ffd700;
  }

  .footer-column ul {
    list-style: none;
  }

  .footer-column li {
    margin-bottom: 12px;
  }

  .footer-column a {
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: var(--transition);
  }

  .footer-column a:hover {
    color: #ffd700;
    padding-left: 5px;
  }

  .copyright {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    font-size: 0.9rem;
    opacity: 0.7;
  }

  /* Responsive Design */
  @media (max-width: 992px) {
    .hero h1 {
      font-size: 2.8rem;
    }
    
    .hero p {
      font-size: 1.1rem;
    }
  }

  @media (max-width: 768px) {
    .navbar {
      flex-direction: column;
      padding: 15px 0;
    }

    .nav-links {
      margin-top: 20px;
    }

    .nav-links li {
      margin: 0 15px;
    }

    .hero {
      padding: 150px 0 80px;
    }

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

    .section {
      padding: 30px;
    }

    .section-title {
      font-size: 2rem;
    }
  }

  @media (max-width: 576px) {
    .hero h1 {
      font-size: 1.8rem;
    }

    .cta-button {
      padding: 12px 30px;
    }

    .section {
      padding: 25px;
    }

    .section-title {
      font-size: 1.8rem;
    }

    .article-content h2 {
      font-size: 1.6rem;
    }

    .article-content h3 {
      font-size: 1.3rem;
    }
  }

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

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

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

  .pulse {
    animation: pulse 4s ease-in-out infinite;
  }

  /* Utility Classes */
  .text-center {
    text-align: center;
  }

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

  .mt-50 {
    margin-top: 50px;
  }

  .reference-note {
    background: rgba(255, 215, 0, 0.1);
    border-left: 4px solid #ffd700;
    padding: 15px;
    margin: 30px 0;
    font-style: italic;
    border-radius: 0 8px 8px 0;
  }

  /* Particle Effect */
  .particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
  }

  .particle {
    position: absolute;
    background: rgba(255, 255, 255, 0.8);
    border-radius: 50%;
    animation: moveParticles linear infinite;
  }

  @keyframes moveParticles {
    0% {
      transform: translateY(0) translateX(0);
      opacity: 0;
    }
    10% {
      opacity: 1;
    }
    90% {
      opacity: 1;
    }
    100% {
      transform: translateY(-100vh) translateX(100px);
      opacity: 0;
    }
  }