/* nk-backfill: L5 넘버링 아코디언 / HD1 좌우 라벨+태그 / HR5 액센트 블록 / CT5 인라인 라인 x2 / FT2 2단 / CF7 원인결과형 */
.nk-backfill {
    --nk-primary: #7A2E3B;
    --nk-bg: #FDF5F7;
    --nk-accent: #2E6B7A;
    font-family: 'Gowun Dodum', sans-serif;
    background: var(--nk-bg);
    color: #4a2129;
}

.nk-backfill h1,
.nk-backfill h2,
.nk-backfill .nk-hd-label,
.nk-backfill .nk-ft-title {
    font-family: 'Inter', sans-serif;
}

/* HD1 */
.nk-backfill .nk-hd {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.75rem;
    padding-bottom: 0.9rem;
    border-bottom: 1px solid rgba(122, 46, 59, 0.18);
    margin-bottom: 2rem;
}

.nk-backfill .nk-hd-label {
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--nk-primary);
    letter-spacing: 0.02em;
}

.nk-backfill .nk-hd-tags {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.nk-backfill .nk-tag {
    background: rgba(46, 107, 122, 0.12);
    color: var(--nk-accent);
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    font-size: 0.78rem;
}

/* HR5: 액센트 컬러 블록 배경 + 흰색 텍스트 */
.nk-backfill .nk-hero {
    background: var(--nk-accent);
    color: #ffffff;
    padding: 2.5rem 2rem;
    border-radius: 0.75rem;
    margin-bottom: 2.5rem;
}

.nk-backfill .nk-hero h1 {
    font-size: 2rem;
    font-weight: 700;
    margin: 0 0 0.6rem;
    color: #ffffff;
}

.nk-backfill .nk-hero-sub {
    color: #eaf4f6;
    font-size: 1rem;
    margin: 0;
}

.nk-backfill .nk-body {
    margin-bottom: 2rem;
}

.nk-backfill .nk-body p {
    line-height: 1.85;
    margin: 0 0 1.1rem;
    color: #4a2129;
}

.nk-backfill .nk-body p:last-child {
    margin-bottom: 0;
}

/* L5: 넘버링 아코디언 (native details/summary) */
.nk-backfill .nk-accordion-group {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin: 2rem 0;
}

.nk-backfill .nk-accordion {
    background: #ffffff;
    border: 1px solid rgba(122, 46, 59, 0.2);
    border-radius: 0.5rem;
    overflow: hidden;
}

.nk-backfill .nk-accordion summary {
    cursor: pointer;
    padding: 1rem 1.25rem;
    font-weight: 700;
    color: var(--nk-primary);
    list-style: none;
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.nk-backfill .nk-accordion summary::-webkit-details-marker {
    display: none;
}

.nk-backfill .nk-accordion summary::before {
    content: '+';
    color: var(--nk-accent);
    font-weight: 700;
    font-size: 1.1rem;
    transition: transform 0.2s ease;
}

.nk-backfill .nk-accordion[open] summary::before {
    transform: rotate(45deg);
}

.nk-backfill .nk-accordion p {
    padding: 0 1.25rem 1.25rem;
    margin: 0;
    line-height: 1.85;
    color: #4a2129;
}

/* CT5: 인라인 CTA 라인 x2 */
.nk-backfill .nk-cta-line {
    border-top: 1px dashed rgba(122, 46, 59, 0.3);
    border-bottom: 1px dashed rgba(122, 46, 59, 0.3);
    padding: 0.85rem 0;
    margin: 2rem 0;
    font-size: 0.95rem;
    text-align: center;
    color: #4a2129;
}

.nk-backfill .nk-cta-line a {
    color: var(--nk-accent);
    font-weight: 700;
    text-decoration: underline;
}

.nk-backfill .nk-cta-line a:focus-visible {
    outline: 2px solid var(--nk-accent);
    outline-offset: 2px;
}

.nk-backfill .nk-figure {
    margin: 2.5rem auto;
    text-align: center;
}

.nk-backfill .nk-figure img {
    width: 100%;
    height: auto;
    border-radius: 0.5rem;
    display: block;
    margin: 0 auto;
}

.nk-backfill .nk-figure figcaption {
    font-size: 0.85rem;
    color: #8a5a63;
    margin-top: 0.5rem;
}

.nk-backfill .nk-link {
    color: var(--nk-accent);
    font-weight: 700;
    text-decoration: underline dotted;
    text-underline-offset: 2px;
    background: none;
    border: none;
    padding: 0;
    cursor: pointer;
    font-size: inherit;
}

.nk-backfill .nk-link:focus-visible {
    outline: 2px solid var(--nk-accent);
    outline-offset: 2px;
}

/* FT2: 2단 */
.nk-backfill .nk-ft {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.75rem;
    border-top: 1px solid rgba(122, 46, 59, 0.2);
    padding-top: 1.75rem;
    margin-top: 2.5rem;
}

.nk-backfill .nk-ft-title {
    display: block;
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--nk-primary);
    margin-bottom: 0.6rem;
}

.nk-backfill .nk-ft-note {
    font-size: 0.82rem;
    color: #8a5a63;
    line-height: 1.6;
    margin: 0.3rem 0 0;
}

@media (max-width: 640px) {
    .nk-backfill .nk-ft {
        grid-template-columns: 1fr;
    }
}

@media (prefers-reduced-motion: reduce) {
    .nk-backfill .nk-accordion summary::before {
        transition: none;
    }
}