#container {
    display: flex;
    flex-direction: column;
    width: 800px;
    aspect-ratio: 1;
}

.line-div {
    display: inline-flex;
    flex-direction:row;
}

.grid-div {
    box-sizing: border-box;
    background-color:antiquewhite;
    flex: auto;
    aspect-ratio: 1;
    
}

.grid-div:hover {
    background-color: black;
}