.select-image-dialog .grid {
    display: grid;
    grid-gap: 10px;
    grid-template-rows: masonry; /* not yet supported */
    grid-template-columns: repeat(4, 1fr);
    max-height: 800px;
    overflow: auto;
    padding: 10px;
}

.select-image-dialog .grid .grid-item {
    position: relative;
    width: 220px;
    height: 220px;
    box-sizing: border-box;
    padding: 10px;
    border: 3px solid lightgray;
    border-radius: 4px;
    background-color: black;
    margin-bottom: 10px;
}

.select-image-dialog .grid .grid-item.selected {
    background-color: #f0f2f4;
}

.select-image-dialog .grid .grid-item.background-dark {
    background-color: black;
}

.select-image-dialog .grid .grid-item.background-light {
    background-color: white;
}

.select-image-dialog .grid .grid-item:hover {
    box-shadow: 0 0 5px 5px #428bca;
    cursor: pointer;
}

.select-image-dialog .grid .grid-item img {
    max-width: 200px;
    max-height: 200px;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.select-image-dialog .grid .grid-item > button {
    width: calc(50% - 2px);
    position: absolute;
    display: none;
    bottom: 2px;
}

.select-image-dialog .grid .grid-item:hover > button {
    display: block;
}

.select-image-dialog .grid .grid-item > button:not([disabled]):hover {
    background-color: #ddd;
}

.select-image-dialog .grid .grid-item > button.remove {
    left: 1px;
}

.select-image-dialog .grid .grid-item > button.make-transparent {
    left: calc(50% + 1px);
}

.select-image-dialog .grid .grid-item .transparent-marker {
    font-size: 2em;
    position: absolute;
    left: -10px;
    top: -10px;
    background-color: white;
    color: grey;
}

.select-image-dialog .grid .grid-item .selected-marker {
    font-size: 4em;
    color: green;
    font-weight: bold;
    position: absolute;
    bottom: -20px;
    right: -20px;
}