#popup-box {
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.2);
    box-sizing: border-box;
    padding-top: 100px;
    position: fixed;
    z-index: 1;
    top: 100px;
    left:0;
    box-shadow: 0px 0px 5px 0px #7f7c7c;
    display: none;
    overflow: auto;
}

    #popup-box .top-bar {
        width: 100%;
        background: red;
        position: relative;
    }

        #popup-box .top-bar #close-button {
            position: absolute;
            top: 15px;
            right: 35px;
            font-size: 20px;
            z-index:1;
           
        }

    #popup-box .content {
        width: 100%;
    }

/* Modal Content (Image) */
.modal-content {
    margin: auto;
    display: block;
    width: 80%;
    max-width: 700px;
}

/* Add Animation */
.modal-content, #caption {
    -webkit-animation-name: zoom;
    -webkit-animation-duration: 0.6s;
    animation-name: zoom;
    animation-duration: 0.6s;
}

@-webkit-keyframes zoom {
    from {
        -webkit-transform: scale(0)
    }

    to {
        -webkit-transform: scale(1)
    }
}

@keyframes zoom {
    from {
        transform: scale(0)
    }

    to {
        transform: scale(1)
    }
}

/* 100% Image Width on Smaller Screens */
@media only screen and (max-width: 700px) {
    .modal-content {
        width: 100%;
    }
}