.loader {
   width: 100vw;
   height: 100vh;
   background: rgba(255, 255, 255, .75);
   position: fixed;
   top: 0;
   left: 0;
   z-index: 99999;
}
.loader > .loader-logo {
   position: absolute;
   top: 50%;
   left: 50%;
   transform: translate(-50%, -50%);
   width: 100px;
   height: 100px;
   background-image: url(../assets/img/sprite_siesa.png);
   background-position: 0 0;
   animation: sprite-logo steps(59) 1500ms infinite;
}
@keyframes sprite-logo {
   0% {
       background-position-y: 0;
   }
   100% {
       background-position-y: -5900px;
   }
}