uccser/cs-field-guide

.pixel-grid {
    padding: 20px;
}

.div-square {
    display: inline-block;
    width: 25px;
    height: 25px;
    border: 1px solid;
    border-color: black;
    border-radius: 0px;
    padding: 0.1rem;
    text-align: center;
    color: black;
    background-color: white;
}

@media (max-width: 535px) {
    .div-square {
        width: 20px;
        height: 20px;
        font-size: 0.8rem;
    }
}

@media (max-width: 435px) {
    .div-square {
        width: 15px;
        height: 15px;
        font-size: 0.5rem;
    }
}

.div-square.active {
    color: white;
    background-color: black;
}