.popup {
    display: none;
    position: fixed;
    z-index: 99999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,.7);
}

.popup-content {
    position: relative;
    width: 70%;
    max-width: 800px;
    margin: 30px auto;
    background: #fff;
    padding: 10px;
    border-radius: 8px;
    animation: zoom .3s;
}

.popup-content img{
    width:100%;
    height:auto;
}

.close {
    position:absolute;
    right:10px;
    top:5px;
    font-size:35px;
    cursor:pointer;
    color:red;
    font-weight:bold;
}

@keyframes zoom{
    from{transform:scale(.7);}
    to{transform:scale(1);}
}

@media(max-width:768px){
    .popup-content{
        width:95%;
        margin-top:20px;
    }
}