:root {
    --primary-dark: #0d47a1;
    --primary-light: #42a5f5;
    --accent: #ff9800;
    --accent-hover: #fb8c00;
    --neutral-light: #f5f5f5;
    --neutral-dark: #333333;
    --white: #ffffff;
    --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: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--neutral-dark);
    background: var(--neutral-light);
    overflow-x: hidden;
  }

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

  /* Header Styles */
  .header {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-light));
    color: var(--white);
    padding: 2rem 0;
    position: relative;
    overflow: hidden;
    box-shadow: var(--shadow);
  }

  .header::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 10px;
    background: linear-gradient(90deg, var(--accent), transparent);
  }

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

  .logo {
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: 1px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.2);
  }

  .notice {
    background: rgba(255,255,255,0.2);
    padding: 10px 15px;
    border-radius: 30px;
    font-size: 0.9rem;
    backdrop-filter: blur(5px);
  }

  /* Navigation */
  .nav {
    display: flex;
    gap: 1.5rem;
  }

  .nav-link {
    color: var(--white);
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 30px;
    transition: var(--transition);
    position: relative;
  }

  .nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 2px;
    background: var(--accent);
    transition: var(--transition);
  }

  .nav-link:hover::after {
    width: 60%;
  }

  /* Hero Section */
  .hero {
    padding: 4rem 0;
    text-align: center;
    position: relative;
  }

  .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: 0.1;
    z-index: -1;
  }

  .hero-title {
    font-size: 2.5rem;
    margin-bottom: 1rem;
    background: linear-gradient(90deg, var(--primary-dark), var(--primary-light));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
  }

  .hero-subtitle {
    font-size: 1.2rem;
    max-width: 700px;
    margin: 0 auto 2rem;
    color: var(--neutral-dark);
  }

  /* Main Content */
  .main {
    padding: 3rem 0;
  }

  article {
    background: var(--white);
    border-radius: 12px;
    padding: 2.5rem;
    box-shadow: var(--shadow);
    margin-bottom: 3rem;
  }

  article h2 {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    color: var(--primary-dark);
    position: relative;
    padding-bottom: 0.5rem;
  }

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

  article h3 {
    font-size: 1.5rem;
    margin: 2rem 0 1rem;
    color: var(--primary-light);
  }

  article p {
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
    line-height: 1.8;
  }

  /* Code Blocks */
  pre {
    background: #2d2d2d;
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    overflow: auto;
    box-shadow: var(--shadow);
  }

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

  .language-css {
    display: block;
  }

  /* Image Gallery */
  .gallery {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
  }

  .gallery-item {
    border-radius: 12px;
    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);
  }

  /* Cards */
  .card-container {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
  }

  .card {
    background: var(--white);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border-top: 4px solid var(--primary-light);
  }

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

  .card-title {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
    color: var(--primary-dark);
  }

  .card-content {
    font-size: 0.95rem;
    color: var(--neutral-dark);
  }

  /* Footer */
  .footer {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-light));
    color: var(--white);
    padding: 2rem 0;
    text-align: center;
  }

  .footer-content {
    max-width: 600px;
    margin: 0 auto;
  }

  .footer-links {
    display: flex;
    justify-content: center;
    gap: 1.5rem;
    margin: 1rem 0;
  }

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

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

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

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

  /* Responsive Design */
  @media (max-width: 768px) {
    .header-content {
      flex-direction: column;
      gap: 1.5rem;
    }

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

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

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

    article {
      padding: 1.5rem;
    }

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

  @media (max-width: 480px) {
    .gallery {
      grid-template-columns: 1fr;
    }
  }