body{
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    flex-direction: column;
}

.container {
    display: flex;
    flex-wrap: wrap;
}

.container > div{
    border: 2px solid black;
    height: 20px;
    width: 20px;
    background-color: black;
}

.container > div:hover{

    background-color: brown;
}