:root {
    --primary: #1e3c72;
    --secondary: #2a5298;
    --accent: #7b2cbf;
    --text: #f8f9fa;
    --text-secondary: #dee2e6;
    --bg: #0a192f;
    --card-bg: rgba(30, 60, 114, 0.2);
    --transition: all 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
  }

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

  body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100%;
    display: flex;
    flex-direction: column;
  }

  .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    width: 100%;
  }

  .header {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    padding: 2rem 0;
    position: relative;
    overflow: hidden;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
  }

  .header::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: 0;
  }

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

  .header h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    background: linear-gradient(to right, #fff, #7b2cbf);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
  }

  .header p {
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto;
    color: var(--text-secondary);
  }

  .notice {
    background: rgba(123, 44, 191, 0.2);
    padding: 1rem;
    border-left: 4px solid var(--accent);
    margin: 2rem 0;
    font-size: 0.9rem;
    border-radius: 0 4px 4px 0;
  }

  .nav {
    display: flex;
    justify-content: center;
    background: rgba(10, 25, 47, 0.9);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 1rem 0;
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
  }

  .nav-link {
    color: var(--text);
    text-decoration: none;
    padding: 0.5rem 1.5rem;
    margin: 0 0.5rem;
    border-radius: 4px;
    transition: var(--transition);
    position: relative;
    font-weight: 500;
  }

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

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

  .nav-link:hover::after {
    width: 70%;
  }

  article {
    padding: 3rem 0;
  }

  article h2 {
    font-size: 2.2rem;
    margin-bottom: 1.5rem;
    color: var(--text);
    position: relative;
    padding-bottom: 0.5rem;
  }

  article h2::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 80px;
    height: 4px;
    background: linear-gradient(to right, var(--accent), transparent);
    border-radius: 2px;
  }

  article h3 {
    font-size: 1.8rem;
    margin: 2.5rem 0 1.5rem;
    color: var(--text);
  }

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

  .card {
    background: var(--card-bg);
    border-radius: 10px;
    padding: 2rem;
    margin: 2rem 0;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    border: 1px solid rgba(123, 44, 191, 0.1);
    transition: var(--transition);
  }

  .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.3);
  }

  .grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 2rem 0;
  }

  .grid-item {
    background: var(--card-bg);
    border-radius: 8px;
    padding: 1.5rem;
    transition: var(--transition);
    border: 1px solid rgba(123, 44, 191, 0.1);
  }

  .grid-item:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
  }

  .grid-item h4 {
    font-size: 1.3rem;
    margin-bottom: 1rem;
    color: var(--text);
  }

  .grid-item p {
    font-size: 1rem;
  }

  .image-container {
    display: flex;
    flex-wrap: wrap;
    gap: 1.5rem;
    margin: 2rem 0;
    justify-content: center;
  }

  .image-box {
    width: 300px;
    height: 300px;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.2);
    transition: var(--transition);
    position: relative;
  }

  .image-box:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
  }

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

  .image-box:hover img {
    transform: scale(1.1);
  }

  .image-box::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to top, rgba(10, 25, 47, 0.7), transparent);
  }

  pre {
    background: rgba(10, 25, 47, 0.7);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    overflow-x: auto;
    border-left: 4px solid var(--accent);
    font-family: 'Courier New', Courier, monospace;
    font-size: 0.95rem;
    line-height: 1.5;
    box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.3);
  }

  code {
    color: #7ee787;
    font-family: 'Courier New', Courier, monospace;
  }

  table {
    width: 100%;
    border-collapse: collapse;
    margin: 2rem 0;
    background: var(--card-bg);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
  }

  th, td {
    padding: 1rem;
    text-align: left;
    border-bottom: 1px solid rgba(123, 44, 191, 0.1);
  }

  th {
    background: rgba(123, 44, 191, 0.2);
    color: var(--text);
    font-weight: 600;
  }

  tr:hover {
    background: rgba(123, 44, 191, 0.1);
  }

  .footer {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    padding: 3rem 0;
    text-align: center;
    margin-top: 3rem;
  }

  .footer p {
    color: var(--text-secondary);
    font-size: 0.9rem;
  }

  @media (max-width: 768px) {
    .header h1 {
      font-size: 2.2rem;
    }
    
    .header p {
      font-size: 1rem;
    }
    
    article h2 {
      font-size: 1.8rem;
    }
    
    article h3 {
      font-size: 1.5rem;
    }
    
    .nav {
      flex-wrap: wrap;
    }
    
    .nav-link {
      padding: 0.5rem 1rem;
      margin: 0.25rem;
      font-size: 0.9rem;
    }
    
    .grid {
      grid-template-columns: 1fr;
    }
    
    .image-box {
      width: 100%;
      max-width: 300px;
    }
  }

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

  @keyframes pulse {
    0%, 100% {
      opacity: 1;
    }
    50% {
      opacity: 0.6;
    }
  }

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

  .pulsing {
    animation: pulse 2s ease-in-out infinite;
  }

  /* Particle effect */
  .particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    overflow: hidden;
  }

  .particle {
    position: absolute;
    background: #fff;
    border-radius: 50%;
    opacity: 0;
    animation: twinkle 5s infinite;
  }

  @keyframes twinkle {
    0% {
      opacity: 0;
      transform: translateY(0) translateX(0);
    }
    50% {
      opacity: 0.8;
    }
    100% {
      opacity: 0;
      transform: translateY(-100px) translateX(50px);
    }
  }

  /* Tooltip */
  .tooltip {
    position: relative;
    display: inline-block;
    border-bottom: 1px dotted var(--text-secondary);
    cursor: help;
  }

  .tooltip .tooltiptext {
    visibility: hidden;
    width: 200px;
    background-color: var(--secondary);
    color: var(--text);
    text-align: center;
    border-radius: 6px;
    padding: 5px;
    position: absolute;
    z-index: 1;
    bottom: 125%;
    left: 50%;
    margin-left: -100px;
    opacity: 0;
    transition: opacity 0.3s;
  }

  .tooltip:hover .tooltiptext {
    visibility: visible;
    opacity: 1;
  }