css

.container .inner:first-child {
    top: 0;
    left: 0;
}

.container .inner:nth-child(2) {
    top: 0;
    right: 0;
}

.container .inner:nth-child(3) {
    bottom: 0;
    left: 0;
}

.container .inner:last-child {
    bottom: 0;
    right: 0;
}