/* VERSION: 5.2.0 */
*,
*::before,
*::after {
    box-sizing: border-box;
}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: #1a1a1a;
    margin: 0;
    font-family: "Segoe UI", sans-serif;
    color: #fff;
}

#game-container {
    display: flex;
    gap: 10px;
    /* Reduced from 40px */
    align-items: flex-start;
    padding-top: 40px;
}

/* --- LEFT COLUMN (History + FEN) --- */
#left-column {
    width: 250px;
    background: #2a2a2a;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    display: flex;
    flex-direction: column;
    gap: 15px;
    height: 640px;
}

#history-panel {
    background: #222;
    border: 1px solid #444;
    border-radius: 4px;
    flex: 1;
    overflow-y: auto;
    padding: 10px;
    font-family: "Courier New", monospace;
    font-size: 14px;
    color: #ccc;
    text-align: left;
}

.history-row {
    display: flex;
    justify-content: space-between;
    padding: 4px 0;
    border-bottom: 1px solid #333;
}

.history-num {
    color: #888;
    width: 30px;
}

.history-move {
    width: 60px;
    text-align: left;
}

.side-btn {
    width: 100%;
    background: #333;
    border: 1px solid #555;
    color: #ddd;
    padding: 10px;
    cursor: pointer;
    font-size: 13px;
    border-radius: 4px;
    transition: background 0.2s;
    margin-bottom: 5px;
}

.side-btn:hover {
    background: #444;
    border-color: #888;
}

/* --- CENTER COLUMN (Graveyards + Board) --- */
#center-column {
    display: flex;
    flex-direction: column;
    gap: 10x;
    /* Reduced from 15px */
    align-items: center;
}

#board-frame {
    width: 640px;
    height: 640px;
    background-color: #333;
    padding: 20px;
    border-radius: 4px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
    position: relative;
}

#chessboard {
    width: 100%;
    height: 100%;
    display: grid;
    grid-template-columns: repeat(8, minmax(0, 1fr));
    grid-template-rows: repeat(8, minmax(0, 1fr));
    border: 5px solid #222;
    transition: opacity 0.2s;
}

#chessboard.board-locked {
    pointer-events: none;
    opacity: 0.7;
    cursor: wait;
}

.square {
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    overflow: hidden;
    font-size: 55px;
}

/* --- HIGHLIGHTING & SELECTION --- */
.square.selected {
    background-color: rgba(255, 215, 0, 0.6) !important;
    outline: 3px solid #ffd700;
    outline-offset: -3px;
}

.square.last-move {
    background-color: rgba(255, 255, 0, 0.3);
}

.square.valid-move::after {
    content: '';
    position: absolute;
    width: 25%;
    height: 25%;
    background-color: rgba(0, 0, 0, 0.3);
    border-radius: 50%;
    pointer-events: none;
}

.square.valid-move.capture-hint::after {
    width: 85%;
    height: 85%;
    background-color: transparent;
    border: 6px solid rgba(0, 0, 0, 0.3);
}

/* --- MARBLE TEXTURES --- */
.white-marble {
    background-color: #e0e0e0;
    color: #333;
    background-image:
        radial-gradient(circle at 50% 50%, rgba(255, 255, 255, 0.8), transparent),
        repeating-linear-gradient(45deg, transparent, transparent 10px, rgba(0, 0, 0, 0.05) 10px, rgba(0, 0, 0, 0.05) 12px);
}

.black-marble {
    background-color: #444;
    color: #f0f0f0;
    background-image:
        radial-gradient(circle at 50% 50%, rgba(255, 255, 255, 0.1), transparent),
        repeating-linear-gradient(45deg, transparent, transparent 10px, rgba(0, 0, 0, 0.1) 10px, rgba(0, 0, 0, 0.1) 12px);
}

/* --- PIECES --- */
.piece {
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: grab;
    user-select: none;
    line-height: 1;
    z-index: 2;
}

.piece:active {
    cursor: grabbing;
}

.piece.white {
    color: #fff;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
    filter: drop-shadow(0 0 1px #000);
}

.piece.black {
    color: #000;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.4);
    filter: drop-shadow(0 0 1px #fff);
}

.piece.dragging-clone {
    position: fixed;
    pointer-events: none;
    z-index: 9999;
    width: 80px;
    height: 80px;
    font-size: 65px;
    opacity: 0.9;
    transform: translate(-50%, -50%);
    cursor: grabbing;
}

/* --- GRAVEYARDS --- */
.graveyard {
    width: 640px;
    min-height: 60px;
    border-radius: 4px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    padding: 10px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.5);
    border: 2px solid #333;
}

.graveyard.black-marble {
    border-color: #555;
}

.graveyard.white-marble {
    border-color: #ccc;
}

.graveyard .piece {
    width: 40px;
    height: 40px;
    font-size: 30px;
    margin: 2px;
    cursor: default;
}

/* --- RIGHT SIDEBAR (Controls) --- */
#sidebar {
    width: 250px;
    background: #2a2a2a;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
    text-align: center;
}

#status-text {
    margin: 0 0 20px 0;
    font-size: 24px;
    border-bottom: 2px solid #444;
    padding-bottom: 10px;
}

#winner-display {
    font-size: 18px;
    margin-bottom: 20px;
    min-height: 24px;
    color: #ffd700;
}

.timers-container {
    margin-bottom: 20px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.timer {
    background-color: #111;
    color: #e0e0e0;
    font-family: 'Courier New', monospace;
    font-size: 32px;
    padding: 10px;
    border-radius: 4px;
    border: 2px solid #444;
}

.timer.active {
    border-color: #4CAF50;
    color: #fff;
    box-shadow: 0 0 10px rgba(76, 175, 80, 0.3);
}

.controls {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.settings-group h3 {
    margin-top: 0;
    margin-bottom: 10px;
    font-size: 16px;
    color: #ccc;
    text-align: left;
}

.mode-toggle {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 14px;
    margin-bottom: 5px;
    text-align: left;
}

.btn {
    padding: 10px 20px;
    font-size: 16px;
    cursor: pointer;
    border: none;
    border-radius: 4px;
    transition: background 0.2s, opacity 0.2s;
}

.btn:disabled {
    background-color: #555 !important;
    cursor: not-allowed;
    opacity: 0.6;
}

.btn.primary {
    background-color: #4CAF50;
    color: white;
}

.btn.primary:hover {
    background-color: #45a049;
}

.btn.warning {
    background-color: #f44336;
    color: white;
}

.btn.warning:hover {
    background-color: #da190b;
}

/* --- MODALS --- */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    z-index: 1000;
    justify-content: center;
    align-items: center;
}

.modal-content {
    background: #222;
    padding: 30px;
    border-radius: 8px;
    border: 1px solid #444;
    text-align: center;
    max-width: 400px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
}

/* README MODAL SPECIFIC */
.readme-content {
    background: #1a1a1a;
    padding: 30px;
    border-radius: 8px;
    border: 1px solid #444;
    text-align: left;
    max-width: 800px;
    width: 90%;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.8);
    position: relative;
    color: #ddd;
    line-height: 1.6;
}

.readme-content h2 {
    color: #ffd700;
    border-bottom: 1px solid #444;
    padding-bottom: 10px;
    margin-top: 0;
}

.readme-content h3 {
    color: #4CAF50;
    margin-top: 20px;
}

.readme-content ul {
    padding-left: 20px;
}

.readme-content code {
    background: #333;
    padding: 2px 5px;
    border-radius: 3px;
    font-family: monospace;
    color: #ff9800;
}

.readme-close {
    position: absolute;
    top: 15px;
    right: 20px;
    font-size: 24px;
    cursor: pointer;
    color: #888;
}

.readme-close:hover {
    color: #fff;
}

.promotion-options {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-top: 20px;
}

.promo-btn {
    width: 60px;
    height: 60px;
    font-size: 40px;
    background: #333;
    border: 2px solid #555;
    color: white;
    cursor: pointer;
    border-radius: 8px;
    display: flex;
    justify-content: center;
    align-items: center;
}

.promo-btn:hover {
    background: #444;
    border-color: #ffd700;
}