#popup {
   visibility: hidden;
   opacity: 0;
   margin-top: -300px;
}

 
#popup:target {
   visibility:visible;
   opacity: 1;
   background-color: rgba(0,0,0,0.8);
   position: fixed;
   top:0;
   left:0;
   right:0;
   bottom:0;
   margin:0;
   z-index: 999;
   -webkit-transition:all 1s;
   -moz-transition:all 1s;
   transition:all 1s;
}

#c1:target {
   visibility:visible;
   opacity: 1;
   background-color: rgba(0,0,0,0.8);
   position: fixed;
   top:0;
   left:0;
   right:0;
   bottom:0;
   margin:0;
   z-index: 999;
   -webkit-transition:all 1s;
   -moz-transition:all 1s;
   transition:all 1s;
}

.contenedor {
 
   margin:7% auto;
   padding:30px 50px;
   background-color: #fafafa;
   color:#333;
   border-radius: 3px;
   width:50%;
   
}
a.popup-cerrar {
   position: absolute;
   top:3px;
   right:31%;
   background-color: #333;
   padding:7px 10px;
   font-size: 20px;
   text-decoration: none;
   line-height: 1;
   color:#fff;
}

/* estilos para el enlace */
    
a.popup-link {
  text-align: center;
  display: block;
  margin: 30px 0;
}

@media only screen and (max-width: 768px) {
a.popup-cerrar {
   position: absolute;
   top:3px;
   right:0%;
   background-color: #333;
   padding:7px 10px;
   font-size: 20px;
   text-decoration: none;
   line-height: 1;
   color:#fff;
}
}
.custom-color {
  color: blue;
}