.box-galeria{ 
 width:100%; 
 float:left; 
}
.box-foto{ 
 width:100%; 
 float:left; 
 margin-bottom:4%; 
 background:#fff; 
 box-shadow: 1px 0px 1.2px 0px #e3e3e3; 
 border-radius:3px; 
 padding:0.5em;
 transition:0.7s; 
}
.box-foto:hover { background-color:#333333; }
@media (min-width:37em){
    .box-foto{ width:23.5%; margin-right:2%; margin-bottom:2%; }
    .box-foto:nth-of-type(4n+0) { margin-right:0; }
}