:root {
      --primary-color: #2c3e50;
      --accent-color: #3498db;
      --bg-color: #ecf0f1;
      --card-bg: #ffffff;
      --font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
      --border-radius: 8px;
      --shadow: 0 2px 8px rgba(0,0,0,0.1);
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: var(--font-family);
      background-color: var(--bg-color);
      color: var(--primary-color);
      line-height: 1.6;
    }
    header {
      background: linear-gradient(135deg, var(--primary-color) 0%, #34495e 100%);
      color: white;
      padding: 3rem 1rem;
      text-align: center;
      box-shadow: var(--shadow);
    }
    header h1 {
      margin: 0;
      font-size: 2.5rem;
      font-weight: 600;
    }
    header p {
      margin: 0.5rem 0 0;
      font-size: 1.3rem;
      opacity: 0.95;
    }
    main {
      padding: 2rem 1rem;
      max-width: 1100px;
      margin: 0 auto;
    }
    .instructor-bio {
      background: var(--card-bg);
      border-radius: var(--border-radius);
      box-shadow: var(--shadow);
      padding: 1.5rem;
      margin-bottom: 2rem;
      border-left: 4px solid var(--accent-color);
      display: flex;
      align-items: center;
      gap: 1rem;
    }
    .instructor-bio img {
      width: 80px;
      height: 80px;
      border-radius: 50%;
      object-fit: cover;
      flex-shrink: 0;
    }
    .instructor-bio p {
      margin: 0;
      font-size: 0.95rem;
      line-height: 1.5;
    }
    .grid {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
      gap: 1.5rem;
      margin-top: 2rem;
    }
    .card {
      background-color: var(--card-bg);
      border-radius: var(--border-radius);
      box-shadow: var(--shadow);
      padding: 1.5rem;
      transition: transform 0.2s, box-shadow 0.2s;
      display: flex;
      flex-direction: column;
    }
    .card:hover {
      transform: translateY(-4px);
      box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    }
    .card h3 {
      margin-top: 0;
      margin-bottom: 0.5rem;
      color: var(--primary-color);
      font-size: 1.3rem;
    }
    .card a {
      color: var(--accent-color);
      text-decoration: none;
      font-weight: bold;
      font-size: 1.1rem;
    }
    .card a:hover {
      text-decoration: underline;
    }
    .card p {
      margin: 0.5rem 0;
      font-size: 0.95rem;
      color: #555;
      flex-grow: 1;
    }
    .card .meta {
      font-size: 0.85rem;
      color: #777;
      margin-top: 1rem;
      padding-top: 1rem;
      border-top: 1px solid #e0e0e0;
    }
    footer {
      text-align: center;
      padding: 2rem 1rem;
      font-size: 0.9rem;
      color: #777;
      background: white;
      margin-top: 2rem;
      box-shadow: 0 -2px 8px rgba(0,0,0,0.05);
    }
    footer a {
      color: var(--accent-color);
      text-decoration: none;
    }
    footer a:hover {
      text-decoration: underline;
    }
    @media (min-width: 1400px) {
      body {
        position: relative;
      }
      .instructor-bio {
        position: fixed;
        right: 2rem;
        top: 8rem;
        width: 280px;
        margin-bottom: 0;
      }
    }
    @media (max-width: 768px) {
      header h1 {
        font-size: 1.8rem;
      }
      .instructor-bio {
        padding: 1rem;
        font-size: 0.9rem;
        flex-direction: column;
        text-align: center;
      }
      .instructor-bio img {
        width: 60px;
        height: 60px;
      }
      .grid {
        grid-template-columns: 1fr;
      }
    }