:root {
    /* Default Theme Variables */
    --bg-color: #f4f4f9;
    --text-color: #333;
    --board-bg: #ffffff;
    --board-border: #333;
    --panel-bg: #fff;
    --panel-text: #333;
    --line-color: #999;
    --empty-node-fill: #fff;
    --empty-node-stroke: #ccc;
    --goat-fill: #2196f3;
    --goat-stroke: #0d47a1;
    --tiger-fill: #ff9800;
    --tiger-stroke: #e65100;
    --selected-ring: #4caf50;
    --last-move-from: rgba(255, 193, 7, 0.5);
    --last-move-to: rgba(255, 193, 7, 0.9);
    --turn-goat-bg: #e3f2fd;
    --turn-goat-text: #1565c0;
    --turn-tiger-bg: #fff3e0;
    --turn-tiger-text: #e65100;
    --winner-color: #d32f2f;
    --help-text: #666;
    --shadow-color: rgba(0,0,0,0.1);
}

/* Traditional Theme - Wooden Board & Stone Pieces */
[data-theme="traditional"] {
    --bg-color: #8b7355;
    --text-color: #2c1810;
    --board-bg: #d4a574;
    --board-border: #6b4423;
    --panel-bg: #f5e6d3;
    --panel-text: #2c1810;
    --line-color: #6b4423;
    --empty-node-fill: #d4a574;
    --empty-node-stroke: #6b4423;
    --goat-fill: #e8e8e8;
    --goat-stroke: #4a4a4a;
    --tiger-fill: #3a2a1a;
    --tiger-stroke: #1a0a00;
    --selected-ring: #ffd700;
    --last-move-from: rgba(139, 69, 19, 0.5);
    --last-move-to: rgba(139, 69, 19, 0.9);
    --turn-goat-bg: #c8b89d;
    --turn-goat-text: #2c1810;
    --turn-tiger-bg: #8b6f47;
    --turn-tiger-text: #2c1810;
    --winner-color: #8b0000;
    --help-text: #5a4a3a;
    --shadow-color: rgba(0,0,0,0.3);
}

/* High Contrast / Dark Mode Theme */
[data-theme="dark"] {
    --bg-color: #1a1a1a;
    --text-color: #ffffff;
    --board-bg: #2d2d2d;
    --board-border: #00ff00;
    --panel-bg: #2d2d2d;
    --panel-text: #ffffff;
    --line-color: #888;
    --empty-node-fill: #2d2d2d;
    --empty-node-stroke: #00ff00;
    --goat-fill: #00ff00;
    --goat-stroke: #00aa00;
    --tiger-fill: #ff00ff;
    --tiger-stroke: #cc00cc;
    --selected-ring: #ffff00;
    --last-move-from: rgba(0, 191, 255, 0.5);
    --last-move-to: rgba(0, 191, 255, 0.9);
    --turn-goat-bg: #003300;
    --turn-goat-text: #00ff00;
    --turn-tiger-bg: #330033;
    --turn-tiger-text: #ff00ff;
    --winner-color: #ffff00;
    --help-text: #cccccc;
    --shadow-color: rgba(0,255,0,0.2);
}

body {
    font-family: Arial, sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding: 20px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

h1 {
    margin-top: 0;
}

#game-container {
    display: flex;
    gap: 30px;
    align-items: flex-start;
    flex-wrap: wrap;
    justify-content: center;
}

canvas {
    background-color: var(--board-bg);
    border: 2px solid var(--board-border);
    border-radius: 8px;
    box-shadow: 0 4px 8px var(--shadow-color);
    cursor: pointer;
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

#ui-panel {
    background: var(--panel-bg);
    color: var(--panel-text);
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 4px 8px var(--shadow-color);
    width: 250px;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.status {
    font-size: 1.2em;
    font-weight: bold;
    margin-bottom: 15px;
    padding: 10px;
    border-radius: 4px;
    text-align: center;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.turn-G {
    background-color: var(--turn-goat-bg);
    color: var(--turn-goat-text);
}

.turn-T {
    background-color: var(--turn-tiger-bg);
    color: var(--turn-tiger-text);
}

.stats {
    margin-bottom: 10px;
    font-size: 1em;
}

.winner-msg {
    color: var(--winner-color);
    font-weight: bold;
    font-size: 1.2em;
    text-align: center;
    margin-top: 20px;
}

/* Theme Selector Styles */
#theme-selector {
    margin-bottom: 20px;
    display: flex;
    gap: 10px;
    align-items: center;
    flex-wrap: wrap;
    justify-content: center;
}

#theme-selector label {
    font-weight: bold;
    margin-right: 10px;
}

.theme-btn {
    padding: 8px 16px;
    border: 2px solid var(--board-border);
    background: var(--panel-bg);
    color: var(--panel-text);
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9em;
    transition: all 0.3s ease;
}

.theme-btn:hover {
    transform: scale(1.05);
    box-shadow: 0 2px 4px var(--shadow-color);
}

.theme-btn.active {
    background: var(--board-border);
    color: var(--board-bg);
    font-weight: bold;
}

.help-text {
    font-size: 0.9em;
    color: var(--help-text);
    margin-top: 30px;
    transition: color 0.3s ease;
}

/* Multiplayer UI Styles */
#multiplayer-menu {
    background: var(--panel-bg);
    color: var(--panel-text);
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 4px 12px var(--shadow-color);
    max-width: 500px;
    margin: 20px auto;
    transition: background-color 0.3s ease, color 0.3s ease;
}

.multiplayer-container h2 {
    margin-top: 0;
    text-align: center;
    color: var(--text-color);
}

.button-group {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: 15px;
}

.mode-btn {
    flex: 1;
    min-width: 150px;
    padding: 12px 20px;
    font-size: 1em;
    font-weight: bold;
    border: 2px solid var(--board-border);
    background: var(--tiger-fill);
    color: white;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.mode-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 8px var(--shadow-color);
}

.mode-btn:active {
    transform: translateY(0);
}

#join-room-section {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: center;
}

#room-code-input {
    flex: 1;
    min-width: 150px;
    padding: 10px;
    font-size: 1em;
    text-transform: uppercase;
    border: 2px solid var(--board-border);
    border-radius: 6px;
    background: var(--panel-bg);
    color: var(--panel-text);
    text-align: center;
    font-weight: bold;
    letter-spacing: 2px;
}

#room-code-input::placeholder {
    color: var(--help-text);
    letter-spacing: normal;
}

#multiplayer-status {
    margin-top: 20px;
    padding: 15px;
    background: var(--turn-goat-bg);
    color: var(--turn-goat-text);
    border-radius: 6px;
    text-align: center;
    font-weight: bold;
    display: none;
}

#room-code-display {
    margin-top: 20px;
}

#game-container.hidden {
    display: none;
}

/* Bot Mode Styles */
.bot-thinking {
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.6;
    }
}