* {
      box-sizing: border-box;
    }

    body {
      margin: 0;
      padding: 0;
      background: linear-gradient(160deg, #0d0d0d 0%, #1a1a1a 100%);
      font-family: 'Amiri', serif;
      color: #d6c9b8;
      display: flex;
      flex-direction: column;
      align-items: center;
      min-height: 100vh;
    }

    h1 {
      margin: 20px 10px 10px;
      font-size: 26px;
      text-shadow: 1px 1px 2px black;
      text-align: center;
    }

    .intro {
      max-width: 700px;
      padding: 0 20px;
      font-size: 18px;
      color: #b0a89f;
      font-style: italic;
      text-align: center;
      margin-bottom: 20px;
      line-height: 1.8;
      transition: color 0.4s ease;
    }

    .intro:hover {
      color: #e0d5c0;
    }

    #book-container {
      position: relative;
      width: 90%;
      max-width: 800px;
      aspect-ratio: 3 / 4;
      overflow: hidden;
      border-radius: 12px;
      border: 1px solid #555;
      box-shadow: 0 0 20px rgba(0, 0, 0, 0.8);
      background-color: #2c2c2c;
    }

    #book-container img {
      width: 100%;
      height: 100%;
      object-fit: contain;
      display: none;
    }

    #book-container img.active {
      display: block;
    }

    .nav-buttons {
      margin: 20px;
      display: flex;
      flex-wrap: wrap;
      gap: 20px;
      justify-content: center;
    }

    .nav-buttons button {
      padding: 12px 24px;
      font-size: 16px;
      border: none;
      border-radius: 12px;
      background: #3b3b3b;
      color: #d6c9b8;
      cursor: pointer;
      transition: all 0.3s ease;
      box-shadow: 0 4px 10px rgba(0, 0, 0, 0.3);
    }

    .nav-buttons button:hover {
      background: #5a5a5a;
      transform: scale(1.05);
    }

    .back-link {
      margin: 40px 0 20px;
      font-size: 16px;
      color: #888;
      font-style: italic;
      text-align: center;
      transition: color 0.4s;
    }

    .back-link a {
      color: #bfa67a;
      text-decoration: none;
      border-bottom: 1px dashed #666;
      transition: color 0.3s;
    }

    .back-link a:hover {
      color: #f1e6d6;
    }

    @media (max-width: 600px) {
      h1 {
        font-size: 20px;
      }

      .intro {
        font-size: 16px;
      }

      .nav-buttons button {
        font-size: 14px;
        padding: 10px 18px;
      }

      #book-container {
        aspect-ratio: 3 / 5;
      }

      .back-link {
        font-size: 14px;
        padding: 0 20px;
      }
    }