.grid-main-post {
    height: 320px;
    position: relative;
    overflow: hidden;
    border-radius: 5px;
}

@media (min-width: 1024px) {
    .grid-main-post {
        height: 480px;
    }
}

.grid-sub-post {
    height: 235px;
    position: relative;
    overflow: hidden;
    border-radius: 5px;
}