html,
body {
    margin: 0;
    padding: 0;
    overflow: hidden;
    height: 100%;
    background: #222;
    font-family: 'Roboto', sans-serif;
    color: #f0f0f0;
}


#flipbook .page.even {
  justify-content: flex-start;  /* Trang bên trái → ảnh lệch phải */
}

#flipbook .page.odd {
  justify-content: flex-end;  /* Trang bên phải → ảnh lệch trái */
}
#flipbook .page {
  height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #111;
}

#flipbook .page img {
  max-height: 100%;
  max-width: 100%;
  object-fit: contain;
  display: block;
}
#page-footer {
    position: absolute;
    bottom: 0;
    width: 100%;
    text-align: right;
    font-size: 14px;
    color: #ccc;
    background-color: rgba(0, 0, 0, 0.7);
    padding: 0px 0;
    z-index: 999;
}





#nav-buttons {
    position: absolute;
    bottom: 20px;
    width: 100%;
    text-align: center;
    z-index: 1000;
}

#nav-buttons button {
    padding: 10px 20px;
    font-size: 16px;
    margin: 0 10px;
    border: none;
    border-radius: 6px;
    background-color: #fff;
    cursor: pointer;
}