@keyframes blur {
     from {background-color: rgba(255, 255, 255, 0); backdrop-filter: blur(0px);}
     to {background-color: rgba(0, 0, 0, 0.439); backdrop-filter: blur(5px); color: rgb(255, 255, 255);}
   }


#maindiv {
     height: 100vh;
     background-image: url("../img/hintergrund_buch.jpg");
     background-size: cover;
     background-position: center;
}
#titeldiv {
     width: 35%;
     margin-left: 10%;
     margin-top: 5%;
     animation-name: blur;
     animation-duration: 2s;
     animation-fill-mode: forwards;
}


.link-pdf {
     text-decoration: none;
     color: white;
}

@media (max-width: 991.98px) {
     #titeldiv {
          width: 97%;
          margin-left: auto;
           
     }

}