:root {
    --background-color: #fafafa;
    --text-color: #333;
    --text-secondary: #555;
    --text-tertiary: #666;
    --border-color: #ddd;
    --hover-color: #f0f0f0;
    --active-color: #333;
    --font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Fira Code', 'Roboto Mono', monospace;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 40px 20px;
    line-height: 1.6;
}

.container {
    max-width: 900px;
    width: 100%;
}

h1 {
    font-size: 2.5rem;
    font-weight: 300;
    color: var(--text-color);
    margin-bottom: 2.5rem;
    text-align: center;
    letter-spacing: -0.5px;
}

.game-info {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 2rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    border: 1px solid var(--border-color);
    background: white;
}

.player-info {
    text-align: center;
}

.player-info h2 {
    font-size: 0.8rem;
    font-weight: 400;
    color: var(--text-tertiary);
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.score-label {
    font-size: 0.7rem;
    font-weight: 400;
    color: var(--text-tertiary);
    margin-bottom: 0.3rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.score {
    font-size: 2rem;
    font-weight: 300;
    color: var(--text-color);
}

.turn-info {
    text-align: center;
}

#turn-display {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 400;
    margin-bottom: 1rem;
}

.controls-container {
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.button-group {
    display: flex;
    gap: 0.5rem;
    justify-content: center;
    flex-wrap: wrap;
}

.button-group.ai-controls {
    padding-top: 0.5rem;
    border-top: 1px solid var(--border-color);
}

#reset-btn, #undo-btn, #ai-toggle-btn, #ai-difficulty {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
    font-family: var(--font-family);
    border: 1px solid var(--border-color);
    background: white;
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.15s ease;
    font-weight: 400;
}

#ai-difficulty {
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%23333' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 0.5rem center;
    padding-right: 2rem;
}

#reset-btn:hover, #undo-btn:hover, #ai-toggle-btn:hover, #ai-difficulty:hover {
    background-color: var(--hover-color);
    border-color: var(--text-color);
}

#ai-toggle-btn.active-ai {
    background-color: var(--text-color);
    color: white;
    border-color: var(--text-color);
}

.board {
    background: white;
    border: 1px solid var(--border-color);
    padding: 2rem;
    margin-bottom: 2rem;
    display: flex;
    align-items: stretch;
    justify-content: center;
    gap: 2rem;
}

.pits-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.store-container {
    display: flex;
    align-items: stretch;
    flex-shrink: 0;
}

.store {
    background: var(--background-color);
    border: 1px solid var(--border-color);
    width: 100px;
    min-height: 180px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    position: relative;
    transition: all 0.15s ease;
}

.store-label {
    position: absolute;
    top: 0.75rem;
    font-size: 0.7rem;
    color: var(--text-tertiary);
    font-weight: 400;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.store .seeds {
    font-size: 2rem;
    font-weight: 300;
    color: var(--text-color);
}

.row {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 0.75rem;
}

.pit {
    background: var(--background-color);
    border: 1px solid var(--border-color);
    aspect-ratio: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    transition: all 0.15s ease;
    position: relative;
}

.pit:hover {
    background: white;
    border-color: var(--text-color);
}

.pit.disabled {
    cursor: not-allowed;
    opacity: 0.4;
}

.pit.disabled:hover {
    background: var(--background-color);
    border-color: var(--border-color);
}

.pit.active {
    background: white;
}

.pit-number {
    position: absolute;
    top: 0.4rem;
    right: 0.5rem;
    font-size: 0.65rem;
    color: var(--text-tertiary);
    font-weight: 400;
}

.seeds {
    font-size: 1.5rem;
    font-weight: 300;
    color: var(--text-color);
}

.rules {
    background: white;
    border: 1px solid var(--border-color);
    padding: 2rem;
    text-align: left;
}

.rules h3 {
    color: var(--text-color);
    margin-bottom: 1rem;
    font-size: 1rem;
    font-weight: 400;
    letter-spacing: 0.5px;
}

.rules ul {
    list-style-position: outside;
    padding-left: 1.5rem;
    color: var(--text-secondary);
    line-height: 1.6;
    font-size: 0.85rem;
}

.rules li {
    margin-bottom: 0.5rem;
}

.rules strong {
    color: var(--text-color);
    font-weight: 500;
}

@media (max-width: 768px) {
    body {
        padding: 1rem;
    }

    h1 {
        font-size: 1.8rem;
        margin-bottom: 1.5rem;
    }

    .game-info {
        grid-template-columns: 1fr;
        gap: 1rem;
        padding: 1rem;
    }

    .board {
        flex-direction: column;
        padding: 1rem;
        gap: 1rem;
    }

    .store-container {
        order: 0;
    }

    .player2-store-container {
        order: 0;
    }

    .pits-container {
        order: 1;
    }

    .player1-store-container {
        order: 2;
    }

    .store {
        width: 100%;
        min-height: 60px;
        height: auto;
        flex-direction: row;
        justify-content: center;
        gap: 1rem;
    }

    .store-label {
        position: static;
    }

    .store .seeds {
        font-size: 1.5rem;
    }

    .pit {
        min-height: 60px;
    }

    .seeds {
        font-size: 1.2rem;
    }

    .rules {
        padding: 1.5rem;
    }

    .button-group {
        gap: 0.4rem;
    }

    #reset-btn, #undo-btn, #ai-toggle-btn, #ai-difficulty {
        font-size: 0.75rem;
        padding: 0.4rem 0.8rem;
    }
}