:root {
    --primary: #3B82F6;
    --secondary: #60A5FA;
    --accent: #BFDBFE;
    --background: #1E3A8A;
    --surface: #2563EB;
    --text: #F3F4F6;
    --text-muted: #9CA3AF;
    --disc-black: #111827;
    --disc-white: #F9FAFB;
    --board-bg: #1F2937;
    --board-grid: #374151;
    --valid-move: rgba(59, 130, 246, 0.4);
    --valid-move-hover: rgba(59, 130, 246, 0.7);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-family);
    background-color: var(--background);
    color: var(--text);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.app-container {
    width: 100%;
    max-width: 800px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

header {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
    background-color: rgba(30, 58, 138, 0.8);
    backdrop-filter: blur(10px);
    padding: 20px;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

h1 {
    margin: 0;
    font-size: 2.5rem;
    font-weight: 800;
    letter-spacing: -0.05em;
    background: linear-gradient(135deg, var(--secondary), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.controls {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    justify-content: center;
    align-items: center;
}

.control-group {
    display: flex;
    align-items: center;
    gap: 8px;
}

label {
    font-size: 0.9rem;
    color: var(--text-muted);
}

select {
    background-color: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: var(--text);
    padding: 6px 12px;
    border-radius: 6px;
    outline: none;
    cursor: pointer;
    transition: all 0.2s;
}

select:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.btn {
    padding: 8px 16px;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.2s;
}

.btn.primary {
    background-color: var(--primary);
    color: white;
}

.btn.primary:hover {
    background-color: var(--secondary);
    transform: translateY(-1px);
}

.btn.secondary {
    background-color: rgba(255, 255, 255, 0.1);
    color: var(--text);
}

.btn.secondary:hover {
    background-color: rgba(255, 255, 255, 0.2);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.game-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    max-width: 600px;
    margin-bottom: 10px;
}

.player-score {
    display: flex;
    align-items: center;
    gap: 10px;
    background-color: rgba(255, 255, 255, 0.05);
    padding: 8px 16px;
    border-radius: 8px;
}

.disc {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    box-shadow: 0 2px 4px rgba(0,0,0,0.3);
}

.disc.black {
    background-color: var(--disc-black);
    border: 2px solid #333;
}

.disc.white {
    background-color: var(--disc-white);
    border: 2px solid #ddd;
}

.turn-indicator {
    font-weight: 600;
    color: var(--accent);
    padding: 6px 12px;
    border-radius: 20px;
    background-color: rgba(59, 130, 246, 0.15);
}

.board-container {
    position: relative;
    padding: 10px;
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: 12px;
    box-shadow: var(--shadow);
}

canvas {
    display: block;
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    cursor: pointer;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.8);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    opacity: 1;
    visibility: visible;
    transition: opacity 0.3s, visibility 0.3s;
}

.modal.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.modal-content {
    background-color: #1F2937;
    padding: 30px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
    transform: translateY(0);
    transition: transform 0.3s;
}

.modal.hidden .modal-content {
    transform: translateY(20px);
}

.modal h2 {
    margin-top: 0;
    color: var(--accent);
}

.modal p {
    font-size: 1.2rem;
    margin-bottom: 20px;
}

/* Responsive */
@media (max-width: 600px) {
    header {
        padding: 15px;
    }

    h1 {
        font-size: 2rem;
    }

    .game-info {
        flex-direction: column;
        gap: 10px;
    }

    .turn-indicator {
        order: -1;
    }

    .controls {
        flex-direction: column;
        align-items: stretch;
    }
}