.main-content {
    padding: 20px;
}

.main-content > section img {
    width: 100%;
    padding: 1.8em;
    background: -webkit-radial-gradient(top left circle,transparent 1em,#282C2D 0) top left,-webkit-radial-gradient(top right circle,transparent 1em,#282C2D 0) top right,-webkit-radial-gradient(bottom right circle,transparent 1em,#282C2D 0) bottom right,-webkit-radial-gradient(bottom left circle,transparent 1em,#282C2D 0) bottom left;
    background: radial-gradient(circle at top left,transparent 1em,#282C2D 0) top left,radial-gradient(circle at top right,transparent 1em,#282C2D 0) top right,radial-gradient(circle at bottom right,transparent 1em,#282C2D 0) bottom right,radial-gradient(circle at bottom left,transparent 1em,#282C2D 0) bottom left;
    background-size: 51% 51%;
    background-repeat: no-repeat;
    outline: 1px dashed #fff;
    outline-offset: -1.2em;
    margin-bottom: 10px;
}