.board {
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    min-height: 800px;
}

.row {
    display: flex;
    justify-content: flex-start;
}

.square {
    width: 100%;
    min-height: 10px;
    background-color: red;
    border: 1px solid #dfdfdf;
}

.start {
    background-color: blueviolet;
}

.seen {
    background-color: burlywood;
}

.goal {
    background-color: green;
}

.slidecontainer {
    width: 100%;
}

.slider {
    -webkit-appearance: none;
    width: 90%;
    height: 25px;
    background: #d3d3d3;
    outline: none;
    opacity: 0.7;
    -webkit-transition: .2s;
    transition: opacity .2s;
    bottom: 0px;
}

.slider:hover {
    opacity: 1;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 25px;
    height: 25px;
    background: #4CAF50;
    cursor: pointer;
}

.slider::-moz-range-thumb {
    width: 25px;
    height: 25px;
    background: #4CAF50;
    cursor: pointer;
}