body{margin:0;padding:0;background-image:url('background.webp');background-repeat:repeat;background-size:auto;background-color:#000}
.bild {
  display: block;
  margin: 0 auto;
  border-radius: 35px;
}
.center-wrapper {
  display: flex;
  justify-content: center; /* horizontal */
  align-items: center;     /* vertikal */
  height: 100vh;           /* volle Fensterhöhe */
}