:root {
    --primary: #2c3e50;
    --secondary: #3498db;
    --accent: #f1c40f;
    --text: #ecf0f1;
    --bg-gradient: linear-gradient(135deg, rgba(135, 206, 235, 0.9) 0%, rgba(176, 224, 230, 0.9) 100%);
    --card-bg: rgba(255, 255, 255, 0.15);
    --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', 'Open Sans', sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg-gradient);
    min-height: 100%;
    padding: 2rem;
    position: relative;
    overflow-x: hidden;
  }

  body::before {
    content: "";
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('https://images.gptkong.com/demo/sample3.png') center/cover no-repeat;
    opacity: 0.05;
    z-index: -1;
  }

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

  .header {
    text-align: center;
    margin-bottom: 3rem;
    position: relative;
  }

  .header::after {
    content: "";
    display: block;
    width: 150px;
    height: 4px;
    background: var(--accent);
    margin: 1.5rem auto;
    border-radius: 2px;
  }

  .notice {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: rgba(0,0,0,0.7);
    color: white;
    padding: 10px 15px;
    border-radius: 5px;
    font-size: 0.8rem;
    z-index: 100;
    backdrop-filter: blur(5px);
  }

  h1, h2, h3, h4 {
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text);
  }

  h1 {
    font-size: 2.5rem;
    background: linear-gradient(90deg, var(--secondary), var(--accent));
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
  }

  h2 {
    font-size: 1.8rem;
    position: relative;
    padding-bottom: 0.5rem;
  }

  h2::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50px;
    height: 3px;
    background: var(--accent);
    border-radius: 3px;
  }

  h3 {
    font-size: 1.4rem;
    color: var(--accent);
  }

  p {
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
    color: rgba(255,255,255,0.9);
  }

  .card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 3rem 0;
  }

  .card {
    background: var(--card-bg);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    padding: 2rem;
    box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.15);
    border: 1px solid rgba(255, 255, 255, 0.18);
    transition: var(--transition);
  }

  .card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.2);
  }

  .card-img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 10px;
    margin-bottom: 1.5rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
    transition: var(--transition);
  }

  .card-img:hover {
    transform: scale(1.02);
  }

  pre {
    background: rgba(0, 0, 0, 0.3);
    border-radius: 8px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    overflow: auto;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    line-height: 1.5;
    border-left: 3px solid var(--accent);
  }

  code {
    color: #f8f8f2;
    background: transparent;
  }

  .nav-tabs {
    display: flex;
    flex-wrap: wrap;
    margin: 2rem 0;
    border-bottom: 1px solid rgba(255,255,255,0.1);
  }

  .nav-tab {
    padding: 0.8rem 1.5rem;
    cursor: pointer;
    transition: var(--transition);
    border-radius: 5px 5px 0 0;
    margin-right: 0.5rem;
    font-weight: 500;
  }

  .nav-tab:hover {
    background: rgba(255,255,255,0.1);
  }

  .nav-tab.active {
    background: rgba(255,255,255,0.2);
    color: var(--accent);
    border-bottom: 2px solid var(--accent);
  }

  .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); }
  }

  .float-img {
    float: right;
    width: 300px;
    margin: 0 0 1rem 2rem;
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0,0,0,0.2);
    shape-outside: circle(50%);
    transition: var(--transition);
  }

  .float-img:hover {
    transform: rotate(2deg);
  }

  .summary {
    background: rgba(0,0,0,0.2);
    padding: 2rem;
    border-radius: 15px;
    margin: 3rem 0;
    border-left: 5px solid var(--accent);
  }

  @media (max-width: 768px) {
    .card-grid {
      grid-template-columns: 1fr;
    }
    
    .float-img {
      float: none;
      width: 100%;
      margin: 1rem 0;
    }
    
    h1 {
      font-size: 2rem;
    }
    
    h2 {
      font-size: 1.5rem;
    }
  }

  .pulse {
    animation: pulse 2s infinite;
  }

  @keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(241, 196, 15, 0.4); }
    70% { box-shadow: 0 0 0 15px rgba(241, 196, 15, 0); }
    100% { box-shadow: 0 0 0 0 rgba(241, 196, 15, 0); }
  }

  .scroll-indicator {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 60px;
    border: 2px solid var(--accent);
    border-radius: 20px;
    opacity: 0.7;
    z-index: 99;
  }

  .scroll-indicator::before {
    content: "";
    position: absolute;
    top: 10px;
    left: 50%;
    width: 6px;
    height: 6px;
    background: var(--accent);
    border-radius: 50%;
    transform: translateX(-50%);
    animation: scroll 2s infinite;
  }

  @keyframes scroll {
    0% { opacity: 1; top: 10px; }
    100% { opacity: 0; top: 40px; }
  }