#chessBoard {
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    grid-template-rows: repeat(8, 1fr);
    border: 0px;
}

.chessSquare {
    background-color: inherit;
    position: relative;
}

.chessSquare.light {
    background: #ccc;
}

.chessSquare.dark {
    background: #656770;
}

.chessPiece {
    width: 90%;
    height: 90%;
    display: block;
    margin: auto;
}

.chessSquare.selected {
    border: 4px solid red;
    box-sizing: border-box;
}

.legalOverlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none; /* Let clicks go through */
    box-sizing: border-box;
    border: 4px dashed red;
    z-index: 10;
}

#chessBoard.flipped {
    transform: rotate(180deg);
}

.chessSquare.light.previous-start {
    background: linear-gradient(rgba(0, 88, 171, 0.3), rgba(0, 88, 171, 0.3)), #ccc;
}

.chessSquare.light.previous-end {
    background: linear-gradient(rgba(0, 88, 171, 0.3), rgba(0, 88, 171, 0.3)), #ccc;
}

.chessSquare.dark.previous-start {
    background: linear-gradient(rgba(0, 88, 171, 0.3), rgba(0, 88, 171, 0.3)), #656770;
}

.chessSquare.dark.previous-end {
    background: linear-gradient(rgba(0, 88, 171, 0.3), rgba(0, 88, 171, 0.3)), #656770;
}

#promotionModal {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: #1e1e1e;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0,0,0,0.6);
    color: white;
    z-index: 1000;
    text-align: center;
}

#promotionModal p {
    margin-bottom: 15px;
    font-size: 18px;
    font-weight: bold;
}

#promotionBtnContainer {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
    justify-content: center;
}

#promotionBtnContainer button {
    background-color: #2c2c2c;
    border: none;
    padding: 10px;
    border-radius: 8px;
    cursor: pointer;
    transition: transform 0.2s ease;
}

#promotionBtnContainer button:hover {
    transform: scale(1.1);
    background-color: #3a3a3a;
}

#promotionBtnContainer img {
    width: 50px;
    height: 50px;
    pointer-events: none; /* ensures img doesn't steal the click */
}

#difficultyModal {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: #1e1e1e;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0,0,0,0.6);
    color: white;
    z-index: 1000;
    text-align: center;
}

#difficultyModal p {
    margin-bottom: 15px;
    font-size: 18px;
    font-weight: bold;
}

#difficultyButtonContainer {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 10px;
    justify-content: center;
}

#difficultyButtonContainer button {
    background-color: #2c2c2c;
    border: none;
    padding: 10px;
    border-radius: 8px;
    cursor: pointer;
    transition: transform 0.2s ease;
    color: white;
}

#difficultyButtonContainer button:hover {
    transform: scale(1.1);
    background-color: #3a3a3a;
}

#difficultyButtonContainer img {
    width: 50px;
    height: 50px;
    pointer-events: none; /* ensures img doesn't steal the click */
}

#colorModal {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background-color: #1e1e1e;
    padding: 20px;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0,0,0,0.6);
    color: white;
    z-index: 1000;
    text-align: center;
}

#colorModal p {
    margin-bottom: 15px;
    font-size: 18px;
    font-weight: bold;
}

#colorButtonContainer {
    display: flex;
    gap: 10px;
    justify-content: center;
}

#colorButtonContainer button {
    background-color: #2c2c2c;
    border: none;
    padding: 10px 18px;
    border-radius: 8px;
    cursor: pointer;
    transition: transform 0.2s ease;
    color: white;
}

#colorButtonContainer button:hover {
    transform: scale(1.1);
    background-color: #3a3a3a;
}

.chessSquare .coordinate-label {
    position: absolute;
    font-size: 1.2vw;
    font-weight: bold;
    pointer-events: none;
    user-select: none;
}

.chessSquare.light .coordinate-label {
    color: #656770;
}

.chessSquare.dark .coordinate-label {
    color: #ccc;
}

.chessSquare .row-label {
    top: 2px;
    left: 4px;
}

.chessSquare .col-label {
    bottom: 2px;
    right: 4px;
}