.sudokugen-wrap {
    max-width: 720px;
    margin: 2rem auto;
    padding: 2rem;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    text-align: center;
    background: linear-gradient(135deg, #fff9f0 0%, #f0f4ff 100%);
    border-radius: 24px;
    box-shadow: 0 8px 32px rgba(0,0,0,0.08);
}

.sudokugen-title {
    font-size: 2rem;
    margin: 0 0 1.5rem;
    color: #333;
}

.sudokugen-section {
    margin-bottom: 1.5rem;
}

.sudokugen-section h3 {
    font-size: 1.05rem;
    color: #555;
    margin: 0 0 0.8rem;
    font-weight: 600;
}

.sudokugen-options {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

.sudokugen-card {
    background: #fff;
    border: 3px solid #e0e0e0;
    border-radius: 16px;
    padding: 14px 20px;
    font-size: 1.05rem;
    cursor: pointer;
    transition: all 0.2s ease;
    min-width: 90px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
    line-height: 1.45;
    font-family: inherit;
    color: #333;
}

.sudokugen-card:hover {
    border-color: #90CAF9;
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(0,0,0,0.1);
}

.sudokugen-card.active {
    border-color: #42A5F5;
    background: linear-gradient(135deg, #E3F2FD, #BBDEFB);
    box-shadow: 0 4px 16px rgba(66,165,245,0.3);
}

.sudokugen-card small {
    color: #888;
    font-size: 0.78rem;
    display: block;
    margin-top: 2px;
}

.sudokugen-checkbox-row {
    margin-top: 1.2rem;
}

.sudokugen-checkbox-label {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 1rem;
    color: #444;
    cursor: pointer;
}

.sudokugen-checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

.sudokugen-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
    margin: 1.8rem 0 0.5rem;
}

.sudokugen-btn {
    padding: 16px 32px;
    font-size: 1.1rem;
    border: none;
    border-radius: 14px;
    cursor: pointer;
    font-weight: 600;
    transition: all 0.2s ease;
    font-family: inherit;
    min-width: 220px;
}

.sudokugen-btn:hover:not(:disabled) {
    transform: translateY(-2px);
}

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

.sudokugen-btn:disabled {
    opacity: 0.7;
    cursor: wait;
}

.sudokugen-btn-primary {
    background: linear-gradient(135deg, #42A5F5, #1E88E5);
    color: #fff;
    box-shadow: 0 4px 12px rgba(33,150,243,0.4);
}

.sudokugen-btn-primary:hover:not(:disabled) {
    box-shadow: 0 6px 20px rgba(33,150,243,0.5);
}

.sudokugen-status {
    min-height: 1.4em;
    margin: 0.6rem 0 0;
    color: #666;
    font-size: 0.95rem;
}

.sudokugen-footer {
    margin: 1rem 0 0;
    color: #aaa;
    font-size: 0.85rem;
}

@media (max-width: 600px) {
    .sudokugen-wrap {
        padding: 1.2rem;
        margin: 1rem;
        border-radius: 18px;
    }
    .sudokugen-title {
        font-size: 1.6rem;
    }
    .sudokugen-card {
        padding: 12px 14px;
        min-width: 78px;
        font-size: 1rem;
    }
    .sudokugen-btn {
        min-width: 100%;
        padding: 14px 20px;
    }
}