:root {
    --primary: #81C784;
    --secondary: #A1887F;
    --neutral: #FFF3E0;
    --accent-blue: #BBDEFB;
    --accent-orange: #FFCC80;
    --text-dark: #333;
    --text-medium: #555;
    --text-light: #fff;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 8px rgba(0,0,0,0.2);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --transition: all 0.3s ease;
  }

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

  body {
    font-family: 'Open Sans', sans-serif;
    line-height: 1.6;
    color: var(--text-medium);
    background: var(--neutral);
    background-image: radial-gradient(circle at 10% 20%, rgba(129,199,132,0.1) 0%, rgba(255,243,224,1) 90%);
    padding: 0;
    margin: 0;
    overflow-x: hidden;
  }

  .notice {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(0,0,0,0.8);
    color: white;
    text-align: center;
    padding: 10px;
    z-index: 1000;
    font-size: 14px;
  }

  .hero {
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary) 30%, var(--secondary) 70%);
    color: var(--text-light);
    padding: 60px 20px;
    position: relative;
    overflow: hidden;
    margin-top: 40px;
  }

  .hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample1.png') no-repeat center right;
    background-size: contain;
    opacity: 0.2;
  }

  .hero-content {
    max-width: 800px;
    text-align: center;
    position: relative;
    z-index: 1;
  }

  .hero h1 {
    font-family: 'Roboto', sans-serif;
    font-size: 2.5rem;
    margin-bottom: 20px;
    text-shadow: 0 2px 4px rgba(0,0,0,0.3);
  }

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

  .scroll-down {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
    color: var(--text-light);
    font-size: 2rem;
  }

  @keyframes bounce {
    0%, 20%, 50%, 80%, 100% {transform: translateY(0) translateX(-50%);}
    40% {transform: translateY(-20px) translateX(-50%);}
    60% {transform: translateY(-10px) translateX(-50%);}
  }

  .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
  }

  article {
    background: white;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: 40px;
    margin-bottom: 40px;
  }

  article h2 {
    font-family: 'Roboto', sans-serif;
    color: var(--primary);
    font-size: 2rem;
    margin-bottom: 20px;
    position: relative;
    padding-bottom: 10px;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 3px;
    background: linear-gradient(90deg, var(--primary), var(--accent-orange));
    border-radius: 3px;
  }

  article h3 {
    font-family: 'Roboto', sans-serif;
    color: var(--secondary);
    font-size: 1.5rem;
    margin: 30px 0 15px;
  }

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

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    box-shadow: var(--shadow-sm);
    border-radius: var(--radius-sm);
    overflow: hidden;
  }

  table th {
    background: var(--primary);
    color: var(--text-light);
    padding: 12px;
    text-align: left;
  }

  table td {
    padding: 10px 12px;
    border-bottom: 1px solid rgba(0,0,0,0.1);
  }

  table tr:nth-child(even) {
    background: rgba(129,199,132,0.1);
  }

  table tr:hover {
    background: rgba(129,199,132,0.2);
  }

  pre {
    background: #f5f5f5;
    border-radius: var(--radius-sm);
    padding: 15px;
    margin: 20px 0;
    overflow-x: auto;
    box-shadow: var(--shadow-sm);
    position: relative;
  }

  pre::before {
    content: 'CSS';
    position: absolute;
    top: 0;
    right: 0;
    background: var(--primary);
    color: white;
    padding: 2px 8px;
    font-size: 0.8rem;
    border-bottom-left-radius: var(--radius-sm);
  }

  code {
    font-family: 'Courier New', monospace;
    color: #333;
  }

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

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

  .gallery-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 20px rgba(0,0,0,0.2);
  }

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

  .gallery-item::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to bottom, rgba(0,0,0,0.1), rgba(0,0,0,0.3));
    opacity: 0;
    transition: var(--transition);
  }

  .gallery-item:hover::after {
    opacity: 1;
  }

  .nav-tabs {
    display: flex;
    margin-bottom: 30px;
    border-bottom: 1px solid rgba(0,0,0,0.1);
  }

  .nav-tab {
    padding: 10px 20px;
    margin-right: 5px;
    background: white;
    border: 1px solid rgba(0,0,0,0.1);
    border-bottom: none;
    border-radius: var(--radius-sm) var(--radius-sm) 0 0;
    cursor: pointer;
    transition: var(--transition);
  }

  .nav-tab:hover {
    background: var(--accent-blue);
  }

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

  .tab-content {
    display: none;
    padding: 20px;
    background: white;
    border-radius: 0 var(--radius-sm) var(--radius-sm) var(--radius-sm);
    box-shadow: var(--shadow-sm);
  }

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

  .accordion {
    margin: 30px 0;
  }

  .accordion-item {
    margin-bottom: 10px;
    border-radius: var(--radius-sm);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
  }

  .accordion-header {
    padding: 15px 20px;
    background: var(--primary);
    color: white;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
  }

  .accordion-header:hover {
    background: #6ab06d;
  }

  .accordion-content {
    padding: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
    background: white;
  }

  .accordion-content-inner {
    padding: 20px;
  }

  .accordion-item.active .accordion-content {
    max-height: 500px;
  }

  .floating-btn {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 60px;
    height: 60px;
    background: var(--accent-orange);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 10px rgba(0,0,0,0.2);
    cursor: pointer;
    transition: var(--transition);
    z-index: 100;
  }

  .floating-btn:hover {
    transform: scale(1.1);
    box-shadow: 0 6px 15px rgba(0,0,0,0.3);
  }

  .floating-btn i {
    color: white;
    font-size: 1.5rem;
  }

  @media (max-width: 768px) {
    .hero h1 {
      font-size: 2rem;
    }
    
    .hero p {
      font-size: 1rem;
    }
    
    article {
      padding: 20px;
    }
    
    .gallery {
      grid-template-columns: 1fr;
    }
  }