.w4i-cost-basis-wrapper {
    max-width: 600px;
    margin: 1.5rem auto;
    padding: 1rem 1.25rem;
    border-radius: 12px;
    border: 1px solid #e3e6eb;
    background: #ffffff;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

.w4i-cb-title {
    margin-top: 0;
    margin-bottom: 0.75rem;
    font-size: 1.05rem;
}

.w4i-cb-intro {
    font-size: 0.85rem;
    margin-top: 0;
    margin-bottom: 1rem;
    color: #555;
}

.w4i-cb-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 0.75rem 1rem;
    margin-bottom: 1rem;
}

.w4i-cb-field {
    display: flex;
    flex-direction: column;
}

.w4i-cb-field label {
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 0.2rem;
}

.w4i-cb-field input {
    padding: 0.4rem 0.5rem;
    border-radius: 8px;
    border: 1px solid #d0d7de;
    font-size: 0.9rem;
}

.w4i-cb-field input:focus {
    outline: none;
    border-color: #ff9800;
    box-shadow: 0 0 0 1px rgba(255,152,0,0.3);
}

.w4i-cb-help {
    font-size: 0.75rem;
    color: #777;
    margin-top: 0.15rem;
}

.w4i-cb-btn {
    padding: 0.6rem 1.4rem;
    border-radius: 999px;
    border: none;
    background: linear-gradient(135deg, #ff9800, #f57c00);
    color: #fff;
    font-weight: 600;
    cursor: pointer;
    font-size: 0.9rem;
}

.w4i-cb-btn:hover {
    opacity: 0.96;
}

.w4i-cb-results {
    margin-top: 1rem;
    font-size: 0.9rem;
}

.w4i-cb-divider {
    margin: 1rem 0;
    border: none;
    border-top: 1px solid #e3e6eb;
}

.w4i-cb-results h4 {
    margin: 0 0 0.5rem 0;
    font-size: 0.95rem;
}

.w4i-cb-results p {
    margin: 0.25rem 0;
}

.w4i-cb-disclaimer {
    font-size: 0.75rem;
    color: #777;
    margin-top: 0.5rem;
}