/* === Sudoku Styles === */
.game-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-6);
    min-height: calc(100vh - var(--nav-height));
    padding-top: calc(var(--nav-height) + var(--space-8));
}

.game-header {
    text-align: center;
}

.difficulty-selector {
    display: flex;
    justify-content: center;
}

.difficulty-buttons {
    display: flex;
    gap: var(--space-2);
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-full);
    padding: 4px;
}

.difficulty-btn {
    padding: var(--space-2) var(--space-5);
    border-radius: var(--radius-full);
    font-size: var(--text-sm);
    font-weight: var(--weight-medium);
    color: var(--text-secondary);
    transition: all var(--transition-fast);
    cursor: pointer;
    border: none;
    background: none;
    font-family: var(--font-body);
}

.difficulty-btn:hover {
    color: var(--text-primary);
}

.difficulty-btn--active {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-sm);
}

.status-bar {
    display: flex;
    align-items: center;
    gap: var(--space-6);
    padding: var(--space-3) var(--space-6);
    background: var(--bg-card);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-xl);
}

.status-bar__item {
    display: flex;
    align-items: center;
    gap: var(--space-2);
}

.status-bar__value {
    font-family: var(--font-mono);
    font-size: var(--text-xl);
    font-weight: var(--weight-bold);
    color: var(--accent-cyan);
    min-width: 3ch;
    text-align: center;
}

/* Board */
.sudoku-board {
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    width: min(90vw, 400px);
    aspect-ratio: 1;
    background: rgba(255, 255, 255, 0.06);
    border: 2px solid var(--accent-primary-bright);
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.sudoku-cell {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: clamp(1rem, 4vw, 1.4rem);
    font-family: var(--font-mono);
    font-weight: var(--weight-bold);
    cursor: pointer;
    border: 1px solid rgba(255, 255, 255, 0.06);
    transition: all var(--transition-fast);
    background: var(--bg-card);
    color: var(--text-primary);
    padding: 0;
    aspect-ratio: 1;
}

.sudoku-cell:hover:not(.sudoku-cell--given) {
    background: var(--bg-card-hover);
}

.sudoku-cell--given {
    color: var(--text-primary);
    cursor: default;
    font-weight: var(--weight-black);
}

.sudoku-cell--selected {
    background: rgba(99, 102, 241, 0.2) !important;
    box-shadow: inset 0 0 0 2px var(--accent-primary-bright);
    z-index: 1;
}

.sudoku-cell--highlight {
    background: rgba(99, 102, 241, 0.08);
}

.sudoku-cell--error {
    color: var(--error) !important;
    background: rgba(248, 113, 113, 0.1) !important;
}

.sudoku-cell--user {
    color: var(--accent-cyan);
}

.sudoku-cell--hint {
    color: var(--success);
}

/* 3x3 box borders */
.sudoku-cell:nth-child(3n) {
    border-right: 2px solid rgba(99, 102, 241, 0.3);
}

.sudoku-cell:nth-child(9n+1) {
    border-left: 2px solid rgba(99, 102, 241, 0.3);
}

.sudoku-cell:nth-child(n+19):nth-child(-n+27) {
    border-bottom: 2px solid rgba(99, 102, 241, 0.3);
}

.sudoku-cell:nth-child(n+46):nth-child(-n+54) {
    border-bottom: 2px solid rgba(99, 102, 241, 0.3);
}

.sudoku-cell:nth-child(-n+9) {
    border-top: 2px solid rgba(99, 102, 241, 0.3);
}

.sudoku-cell:nth-child(n+73) {
    border-bottom: 2px solid rgba(99, 102, 241, 0.3);
}

/* Numpad */
.numpad {
    display: flex;
    gap: var(--space-2);
    flex-wrap: wrap;
    justify-content: center;
    max-width: 400px;
}

.numpad-btn {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-md);
    font-size: var(--text-lg);
    font-weight: var(--weight-bold);
    font-family: var(--font-mono);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    border: 1px solid var(--glass-border);
    background: var(--bg-card);
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.numpad-btn:hover {
    background: var(--bg-card-hover);
    border-color: rgba(99, 102, 241, 0.3);
    transform: scale(1.05);
}

.numpad-btn--active {
    background: var(--gradient-primary);
    border-color: transparent;
    color: white;
}

.numpad-btn--erase {
    background: rgba(248, 113, 113, 0.15);
    border-color: rgba(248, 113, 113, 0.3);
    color: var(--error);
}

.numpad-btn--disabled {
    opacity: 0.3;
    cursor: default;
    pointer-events: none;
}

.game-actions {
    display: flex;
    gap: var(--space-3);
}

@media (max-width:480px) {
    .numpad-btn {
        width: 36px;
        height: 36px;
        font-size: var(--text-base);
    }
}