:root {
    --primary: #1E3A8A;
    --secondary: #FF7E00;
    --accent: #3B82F6;
    --light: #F5F5F5;
    --dark: #333;
    --white: #fff;
    --shadow: 0 4px 20px rgba(0,0,0,0.1);
    --radius: 12px;
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  }

  @font-face {
    font-family: 'Montserrat';
    src: url('https://fonts.googleapis.com/css2?family=Montserrat:wght@400;700&display=swap');
  }

  @font-face {
    font-family: 'Roboto';
    src: url('https://fonts.googleapis.com/css2?family=Roboto:wght@300;400;500&display=swap');
  }

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

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

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

  /* Header Styles */
  header {
    background: linear-gradient(135deg, var(--primary), var(--accent));
    padding: 1.5rem 0;
    box-shadow: var(--shadow);
    position: relative;
    z-index: 100;
  }

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

  .logo {
    font-family: 'Montserrat', sans-serif;
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--white);
    text-decoration: none;
    display: flex;
    align-items: center;
  }

  .logo img {
    width: 40px;
    margin-right: 10px;
  }

  .notice {
    background: rgba(255,255,255,0.2);
    padding: 10px 20px;
    border-radius: 30px;
    color: var(--white);
    font-size: 0.9rem;
    text-align: center;
    margin-top: 20px;
  }

  /* Hero Section */
  .hero {
    padding: 5rem 0;
    background: linear-gradient(rgba(30,58,138,0.9), rgba(30,58,138,0.9)), 
                url('https://images.gptkong.com/demo/sample1.png') center/cover no-repeat;
    color: var(--white);
    text-align: center;
    position: relative;
    overflow: hidden;
  }

  .hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at 20% 50%, rgba(255,126,0,0.2) 0%, transparent 50%);
    z-index: 1;
  }

  .hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    margin: 0 auto;
  }

  .hero h1 {
    font-family: 'Montserrat', sans-serif;
    font-size: 3rem;
    margin-bottom: 1.5rem;
    line-height: 1.2;
    text-shadow: 0 2px 10px rgba(0,0,0,0.3);
  }

  .hero p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    opacity: 0.9;
  }

  /* Main Content */
  main {
    padding: 4rem 0;
  }

  article {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 3rem;
    margin-bottom: 3rem;
  }

  article h2 {
    font-family: 'Montserrat', sans-serif;
    color: var(--primary);
    font-size: 2rem;
    margin-bottom: 1.5rem;
    position: relative;
    padding-bottom: 10px;
  }

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

  article h3 {
    font-family: 'Montserrat', sans-serif;
    color: var(--primary);
    font-size: 1.5rem;
    margin: 2rem 0 1rem;
  }

  article p {
    margin-bottom: 1.5rem;
    font-size: 1.1rem;
    color: var(--dark);
  }

  /* Code Blocks */
  pre {
    background: #282c34;
    border-radius: var(--radius);
    padding: 1.5rem;
    margin: 2rem 0;
    overflow: auto;
    position: relative;
  }

  pre::before {
    content: 'CSS';
    position: absolute;
    top: 0;
    left: 0;
    background: var(--secondary);
    color: var(--white);
    padding: 0.2rem 1rem;
    border-radius: var(--radius) 0 var(--radius) 0;
    font-size: 0.8rem;
    font-weight: bold;
  }

  code {
    font-family: 'Courier New', monospace;
    color: #abb2bf;
    font-size: 0.9rem;
    line-height: 1.5;
  }

  /* Image Gallery */
  .gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
  }

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

  .gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.15);
  }

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

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

  /* Navigation */
  .nav-links {
    display: flex;
    gap: 2rem;
  }

  .nav-links a {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding: 0.5rem 0;
  }

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

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

  /* Footer */
  footer {
    background: var(--primary);
    color: var(--white);
    padding: 3rem 0;
    text-align: center;
  }

  .footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .footer-links {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    justify-content: center;
  }

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

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

  .copyright {
    opacity: 0.8;
    font-size: 0.9rem;
  }

  /* Responsive */
  @media (max-width: 768px) {
    .hero h1 {
      font-size: 2.2rem;
    }

    article {
      padding: 2rem;
    }

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

  /* Animations */
  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
  }

  .animate {
    animation: fadeIn 0.8s ease forwards;
  }

  .delay-1 { animation-delay: 0.2s; }
  .delay-2 { animation-delay: 0.4s; }
  .delay-3 { animation-delay: 0.6s; }

  /* Utility Classes */
  .text-center { text-align: center; }
  .mb-1 { margin-bottom: 1rem; }
  .mb-2 { margin-bottom: 2rem; }
  .mb-3 { margin-bottom: 3rem; }
  .mt-1 { margin-top: 1rem; }
  .mt-2 { margin-top: 2rem; }
  .mt-3 { margin-top: 3rem; }
  .py-1 { padding-top: 1rem; padding-bottom: 1rem; }
  .py-2 { padding-top: 2rem; padding-bottom: 2rem; }
  .py-3 { padding-top: 3rem; padding-bottom: 3rem; }