.day09-grid {
    display: grid;
    grid-template-columns: 175px 40px 175px 40px 175px;
    grid-template-rows: auto;
    justify-content: center;
}

.day09-grid > div {
    align-self: center;
    text-align: center;
}

@media only screen and (max-width: 770px) {
    .day09-grid {
        display: grid;
        grid-template-columns: 175px 40px 175px 40px;
        grid-template-rows: auto auto;
        justify-content: center;
        row-gap: 10px;
    }

    .day09-grid > div:nth-child(5) {
        grid-column-start: 1;
        grid-column-end: 4;
    }
}

@media only screen and (max-width: 450px) {
    .day09-grid {
        display: grid;
        grid-template-columns: auto;
        grid-template-rows: auto;
        justify-content: center;
        row-gap: 10px;
    }

    .day09-grid > div {
        grid-column-start: 1;
        grid-column-end: 1;
    }
}

.day12-image2 {
    height: 310px;
    max-height: 310px;
    background: url(/img/writeup/hackvent/2019/day12_ida2.jpg) no-repeat center top;
}

.day12-image3 {
    height: 200px;
    background: url(/img/writeup/hackvent/2019/day12_ida3.jpg) no-repeat center top;
}

.day12-image4 {
    height: 200px;
    background: url(/img/writeup/hackvent/2019/day12_ida4.jpg) no-repeat center top;
}

.day16-image {
    height:220px;
    background: url(/img/writeup/hackvent/2019/day16_ida2.jpg) no-repeat center top;
}

.day20-image1 {
    height:250px; max-height:250px;
    background: url(/img/writeup/hackvent/2019/day20_ida1.jpg) no-repeat center top;
}
.day20-image2 {
    height:250px; max-height:250px;
    background: url(/img/writeup/hackvent/2019/day20_ida2.jpg) no-repeat center top;
}
.day20-image3 {
    height:250px; max-height:250px;
    background: url(/img/writeup/hackvent/2019/day20_ida3.jpg) no-repeat center top;
}