.product-section {
    background: #f7f9fa;
}

.product-filter {
    padding: 34px;
    border-top: 4px solid var(--red);
    background: var(--white);
    box-shadow: var(--shadow);
}

.filter-heading {
    margin-bottom: 22px;
}

.filter-heading h2 {
    font-size: 32px;
}

.filter-fields {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
}

.filter-fields label {
    display: flex;
    flex: 1 1 210px;
    flex-direction: column;
    gap: 7px;
    color: var(--navy);
    font-weight: 700;
}

.filter-status {
    min-height: 24px;
    margin-top: 10px;
    color: var(--steel);
}

.filter-actions {
    display: flex;
    gap: 12px;
    margin-top: 18px;
}

.product-layout {
    display: flex;
    align-items: flex-start;
    gap: 28px;
    padding-top: 42px;
}

.part-tree {
    flex: 0 0 260px;
    padding: 24px;
    border: 1px solid var(--line);
    background: var(--white);
}

.part-tree h2 {
    padding-bottom: 16px;
    border-bottom: 2px solid var(--red);
    font-size: 22px;
}

.part-tree-status {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 20px 0;
    color: var(--muted);
}

.part-group {
    border-bottom: 1px solid var(--line);
}

.part-group-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 14px 0;
    border: 0;
    color: var(--navy);
    background: transparent;
    font-weight: 700;
    text-align: left;
}

.part-group-toggle svg {
    width: 16px;
    fill: none;
    stroke: currentColor;
    stroke-linecap: round;
    stroke-linejoin: round;
    stroke-width: 2;
    transition: transform 180ms ease;
}

.part-group-toggle[aria-expanded="true"] svg {
    transform: rotate(180deg);
}

.part-items {
    padding: 0 0 12px 10px;
}

.part-items a,
.part-load-state {
    display: block;
    padding: 8px 6px;
    color: var(--muted);
    font-size: 13px;
}

.part-items a:hover,
.part-items a:focus-visible,
.part-items a.is-active {
    color: var(--red);
}

.part-load-state {
    display: flex;
    align-items: center;
    gap: 8px;
}

.product-results {
    position: relative;
    flex: 1 1 auto;
    min-width: 0;
}

.results-loading {
    display: flex;
    position: absolute;
    inset: 0;
    z-index: 5;
    align-items: flex-start;
    justify-content: center;
    gap: 10px;
    padding-top: 90px;
    background: rgba(247, 249, 250, 0.86);
    color: var(--navy);
    font-weight: 700;
}

.product-results .product-card {
    flex-basis: 100%;
}

@media (max-width: 900px) {
    .product-layout {
        flex-direction: column;
    }

    .part-tree {
        flex-basis: auto;
        width: 100%;
    }

    .product-results {
        width: 100%;
    }
}

@media (max-width: 640px) {
    .product-filter {
        padding: 26px 18px;
    }

    .filter-fields label,
    .filter-actions .button {
        flex-basis: 100%;
    }

    .filter-actions {
        flex-wrap: wrap;
    }
}