#expolog {
     display: inline-block;
     position: fixed;
     z-index: 1000;
     width: 450px;
     height: 450px;
     bottom: 84px;
     left: 50%;
     transform: translate(-50%, 0%);
     -webkit-transform: translate(-50%, 0%);
 }

 #cerrar {
     display: block;
     position: absolute;
     width: 40px;
     height: 40px;
     right: 0;
     top: 0px;
     padding: 0;
     font-family: sans-serif;
     font-size: 2em;
     color: black;
     text-align: center;
     cursor: pointer;
     -webkit-transition: all 0.2s;
     -moz-transition: all 0.2s;
     transition: all 0.2s;
 }
#cerrar:hover{
    color: orange;
}      

 #expolog img {
     width: 100%;
 }

 @media (max-width: 700px) {
     #expolog {
         width: 350px;
         height 350px;
         bottom: 50px;
         ;
     }

 }