body {
  font-family: Arial, sans-serif;
  margin: 1em;
  align-items: center;
  line-height: 1.5;
  font-size: 1.2em
}

input[type="file"] {
  margin-bottom: 10px;
}

input[type="submit"] {
  cursor: pointer;
}
.popup {
  position: fixed;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background-color: rgba(0, 0, 0, 0.5);
  display: none;
}