:root {
    --primary: #3498db;
    --secondary: #f39c12;
    --dark: #2c3e50;
    --light: #ecf0f1;
    --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: 'Montserrat', sans-serif;
    line-height: 1.8;
    color: var(--dark);
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8eb 100%);
    min-height: 100%;
    overflow-x: hidden;
  }
  .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
  }
  .header {
    text-align: center;
    padding: 40px 0;
    position: relative;
  }
  .header::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    border-radius: 2px;
  }
  h1, h2, h3, h4 {
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--dark);
  }
  h1 {
    font-size: 2.5rem;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
  }
  h2 {
    font-size: 1.8rem;
    position: relative;
    padding-bottom: 10px;
  }
  h2::after {
    content: "";
    position: absolute;
    bottom: 0;
    left: 0;
    width: 60px;
    height: 3px;
    background: var(--secondary);
  }
  h3 {
    font-size: 1.4rem;
    color: var(--primary);
  }
  p {
    margin-bottom: 20px;
    font-size: 1.1rem;
  }
  article {
    background: var(--white);
    border-radius: 10px;
    box-shadow: var(--shadow);
    padding: 40px;
    margin: 40px 0;
    position: relative;
    overflow: hidden;
  }
  article::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    width: 5px;
    height: 100%;
    background: linear-gradient(to bottom, var(--primary), var(--secondary));
  }
  .note {
    background: rgba(52, 152, 219, 0.1);
    border-left: 4px solid var(--primary);
    padding: 20px;
    margin: 30px 0;
    border-radius: 0 5px 5px 0;
    font-style: italic;
  }
  pre {
    background: #2c3e50;
    color: #ecf0f1;
    padding: 20px;
    border-radius: 5px;
    margin: 20px 0;
    overflow-x: auto;
    font-family: 'Courier New', monospace;
    position: relative;
  }
  pre::before {
    content: "CSS";
    position: absolute;
    top: 0;
    right: 0;
    background: var(--secondary);
    color: white;
    padding: 2px 10px;
    font-size: 0.8rem;
    border-radius: 0 0 0 5px;
  }
  code {
    font-family: 'Courier New', monospace;
    background: rgba(52, 152, 219, 0.1);
    padding: 2px 5px;
    border-radius: 3px;
    color: var(--primary);
  }
  table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    box-shadow: var(--shadow);
  }
  th, td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid #ddd;
  }
  th {
    background: var(--primary);
    color: white;
  }
  tr:nth-child(even) {
    background: rgba(52, 152, 219, 0.05);
  }
  tr:hover {
    background: rgba(52, 152, 219, 0.1);
  }
  .gallery {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin: 30px 0;
  }
  .gallery img {
    width: 100%;
    height: auto;
    border-radius: 8px;
    box-shadow: var(--shadow);
    transition: var(--transition);
  }
  .gallery img:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
  }
  .design-ref {
    position: fixed;
    bottom: 20px;
    right: 20px;
    background: var(--primary);
    color: white;
    padding: 10px 15px;
    border-radius: 30px;
    font-size: 0.9rem;
    z-index: 100;
    box-shadow: 0 4px 15px rgba(52, 152, 219, 0.3);
  }
  @media (max-width: 768px) {
    h1 {
      font-size: 2rem;
    }
    h2 {
      font-size: 1.5rem;
    }
    article {
      padding: 30px 20px;
    }
  }