:root {
    --primary: #1E90FF;
    --secondary: #32CD32;
    --accent: #FF6B6B;
    --dark: #2C3E50;
    --light: #F5F7FA;
    --text: #333;
    --text-light: #7F8C8D;
  }

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

  body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    padding: 0;
    margin: 0;
    overflow-x: hidden;
  }

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

  .header {
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    padding: 30px 0;
    text-align: center;
    color: white;
    margin-bottom: 40px;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
  }

  .header::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample3.png') no-repeat center/cover;
    opacity: 0.1;
    z-index: 0;
  }

  .header-content {
    position: relative;
    z-index: 1;
  }

  h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.2);
  }

  .subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 800px;
    margin: 0 auto;
  }

  .design-notice {
    background: white;
    color: var(--dark);
    padding: 10px 20px;
    border-radius: 30px;
    display: inline-block;
    margin-top: 20px;
    font-weight: bold;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    animation: pulse 2s infinite;
  }

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

  .content-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 40px;
    margin-bottom: 60px;
  }

  article {
    background: white;
    border-radius: 15px;
    padding: 40px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    position: relative;
    overflow: hidden;
  }

  article::after {
    content: "";
    position: absolute;
    top: 0;
    right: 0;
    width: 100px;
    height: 100px;
    background: url('https://images.gptkong.com/demo/sample6.png') no-repeat center/contain;
    opacity: 0.1;
    z-index: 0;
  }

  article > * {
    position: relative;
    z-index: 1;
  }

  h2 {
    font-size: 2rem;
    color: var(--primary);
    margin-bottom: 25px;
    position: relative;
    padding-bottom: 10px;
  }

  h2::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: 2px;
  }

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

  p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 20px;
    color: var(--text);
  }

  .image-gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin: 30px 0;
  }

  .gallery-item {
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s, box-shadow 0.3s;
  }

  .gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0, 0, 0, 0.15);
  }

  .gallery-item img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.5s;
  }

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

  pre {
    background: #282C34;
    color: #ABB2BF;
    padding: 20px;
    border-radius: 8px;
    overflow-x: auto;
    margin: 25px 0;
    box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.5);
    font-family: 'Fira Code', monospace;
    font-size: 0.95rem;
    line-height: 1.5;
    position: relative;
  }

  pre::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary), var(--secondary));
  }

  code {
    font-family: 'Fira Code', monospace;
    background: rgba(30, 144, 255, 0.1);
    padding: 2px 6px;
    border-radius: 4px;
    color: var(--primary);
    font-size: 0.9em;
  }

  .nav-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 30px;
  }

  .nav-tab {
    padding: 10px 20px;
    background: white;
    border-radius: 30px;
    cursor: pointer;
    font-weight: 600;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
    transition: all 0.3s;
  }

  .nav-tab:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
  }

  .nav-tab.active {
    background: var(--primary);
    color: white;
  }

  .tab-content {
    display: none;
    animation: fadeIn 0.5s ease;
  }

  .tab-content.active {
    display: block;
  }

  @keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
  }

  .floating-shapes {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
  }

  .shape {
    position: absolute;
    border-radius: 50%;
    opacity: 0.1;
    filter: blur(30px);
  }

  .shape-1 {
    width: 300px;
    height: 300px;
    background: var(--primary);
    top: -100px;
    right: -100px;
    animation: float 15s infinite ease-in-out;
  }

  .shape-2 {
    width: 200px;
    height: 200px;
    background: var(--secondary);
    bottom: -50px;
    left: -50px;
    animation: float 12s infinite ease-in-out reverse;
  }

  @keyframes float {
    0% { transform: translate(0, 0) rotate(0deg); }
    50% { transform: translate(20px, 20px) rotate(180deg); }
    100% { transform: translate(0, 0) rotate(360deg); }
  }

  .highlight-box {
    background: linear-gradient(135deg, rgba(30, 144, 255, 0.1) 0%, rgba(50, 205, 50, 0.1) 100%);
    border-left: 4px solid var(--primary);
    padding: 25px;
    border-radius: 0 8px 8px 0;
    margin: 30px 0;
  }

  .footer {
    text-align: center;
    padding: 30px 0;
    color: var(--text-light);
    font-size: 0.9rem;
  }

  @media (max-width: 768px) {
    .container {
      padding: 15px;
    }
    
    article {
      padding: 25px;
    }
    
    h1 {
      font-size: 2rem;
    }
    
    h2 {
      font-size: 1.7rem;
    }
    
    h3 {
      font-size: 1.3rem;
    }
    
    .image-gallery {
      grid-template-columns: 1fr;
    }
  }