body {
      margin: 0;
      background-color: #f5f5f5;
      font-family: sans-serif;
      text-align: center;
    }

    h1 {
      margin-top: 30px;
    }

    .iframe-container {
      position: relative;
      width: 90%;
      height: 90vh;
      margin: 30px auto;
      box-shadow: 0 4px 12px rgba(0,0,0,0.2);
    }

    iframe {
      width: 100%;
      height: 100%;
      border: none;
    }

.epub-beschreibung {
  max-width: 75%;
  margin: 40px auto;
  font-size: 1.1rem;
  line-height: 1.7;
  color: #003366;
  text-align: left;
}