.chess-board {
    width: var(--board-size);
    height: var(--board-size);
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    grid-template-rows: repeat(8, 1fr);
    border: 1px solid #000;
    box-shadow: 0 8px 24px rgba(0,0,0,0.3);
    position: relative;
    min-height: 0; /* Prevents overflow */
}

/* Add board coordinates */
.chess-board::before,
.chess-board::after,
.square::before,
.square::after {
    position: absolute;
    color: rgba(0, 0, 0, 0.5);
    font-size: 0.7rem;
    font-weight: normal;
    z-index: 2;
    pointer-events: none;
    padding: 0 2px;
    border-radius: 2px;
    background-color: rgba(255, 255, 255, 0.3);
    line-height: 1;
    display: var(--show-coords, none);
}

/* Adjust color specifically for dark squares */
.square.dark::before,
.square.dark::after {
    color: rgba(255, 255, 255, 0.6);
    background-color: rgba(0, 0, 0, 0.2);
}

/* File coordinates (a-h) - Positioned slightly inside */
.square::before {
    bottom: 2px;
    left: 2px;
}
.square[data-col="0"]::before { content: 'a'; }
.square[data-col="1"]::before { content: 'b'; }
.square[data-col="2"]::before { content: 'c'; }
.square[data-col="3"]::before { content: 'd'; }
.square[data-col="4"]::before { content: 'e'; }
.square[data-col="5"]::before { content: 'f'; }
.square[data-col="6"]::before { content: 'g'; }
.square[data-col="7"]::before { content: 'h'; }

/* Rank coordinates (1-8) - Positioned slightly inside */
.square::after {
    top: 2px;
    right: 2px;
}
.square[data-row="7"]::after { content: '1'; }
.square[data-row="6"]::after { content: '2'; }
.square[data-row="5"]::after { content: '3'; }
.square[data-row="4"]::after { content: '4'; }
.square[data-row="3"]::after { content: '5'; }
.square[data-row="2"]::after { content: '6'; }
.square[data-row="1"]::after { content: '7'; }
.square[data-row="0"]::after { content: '8'; }

/* Hide file coordinate on a1 and rank coordinate on h8 for less clutter */
.square[data-row="7"][data-col="0"]::before { display: none !important; }
.square[data-row="0"][data-col="7"]::after { display: none !important; }

.square {
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    cursor: pointer;
    transition: all 0.15s ease;
    min-height: 0; /* Ensures squares don't expand too much */
    min-width: 0;
}

.square:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: -2px;
}

.square:hover {
    filter: brightness(1.08);
}

.square.light {
    background-color: var(--light-square);
    /* Subtle texture - reduced intensity */
    background-image: linear-gradient(rgba(255,255,255,0.01) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(255,255,255,0.01) 1px, transparent 1px);
    background-size: 4px 4px;
}

.square.dark {
    background-color: var(--dark-square);
    /* Subtle texture - reduced intensity */
    background-image: linear-gradient(rgba(0,0,0,0.02) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(0,0,0,0.02) 1px, transparent 1px);
    background-size: 4px 4px;
}

.square.selected {
    background-color: var(--selected-square);
    box-shadow: inset 0 0 15px rgba(255, 217, 0, 0.2);
    z-index: 1;
}

.square.possible-move::after {
    content: '';
    position: absolute;
    width: 25%;
    height: 25%;
    background-color: var(--possible-move-square);
    border-radius: 50%;
    pointer-events: none;
    animation: pulse 2s infinite;
    display: var(--show-possible-moves);
}

@keyframes pulse {
    0% { transform: scale(0.95); opacity: 0.6; }
    50% { transform: scale(1.05); opacity: 0.8; }
    100% { transform: scale(0.95); opacity: 0.6; }
}

.square.possible-move.light::after {
    box-shadow: 0 0 8px rgba(0, 0, 0, 0.5);
}

.square.possible-move.dark::after {
    box-shadow: 0 0 8px rgba(255, 255, 255, 0.5);
}

/* Highlight for the king in check */
.square.in-check {
    background-color: var(--check-square);
    animation: check-pulse 1.5s ease infinite alternate;
}

@keyframes check-pulse {
    from { box-shadow: inset 0 0 5px rgba(255, 0, 0, 0.3); }
    to { box-shadow: inset 0 0 15px rgba(255, 0, 0, 0.5); }
}

/* Last move indication - using corner markers */
.square.last-move-from::before,
.square.last-move-to::before,
.square.last-move-from::after,
.square.last-move-to::after {
    content: '';
    position: absolute;
    width: 12%;
    height: 12%;
    background-color: rgba(70, 130, 180, 0.5); /* Steel Blue - more transparent */
    z-index: 1;
    display: var(--show-last-move); /* Control visibility */
}

/* Top-left corner */
.square.last-move-from::before {
    top: 0;
    left: 0;
    border-bottom-right-radius: 5px;
}

/* Bottom-right corner */
.square.last-move-from::after {
    bottom: 0;
    right: 0;
    border-top-left-radius: 5px;
}

/* Top-right corner */
.square.last-move-to::before {
    top: 0;
    right: 0;
    border-bottom-left-radius: 5px;
}

/* Bottom-left corner */
.square.last-move-to::after {
    bottom: 0;
    left: 0;
    border-top-right-radius: 5px;
}