/* ============================================================
   ARCHIVE.CSS — 디스코그래피 플립 카드
   ============================================================ */

.archive-main {
  padding-top: 64px;
  min-height: 100vh;
}

.archive-header {
  padding: 0 40px;
}

.back-link {
  display: inline-block;
  margin-top: 32px;
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  color: var(--text-muted);
  transition: color 0.3s;
}
.back-link:hover { color: var(--gold); }

.archive-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  max-width: 480px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ── 필터 탭 ── */
.filter-tabs {
  display: flex;
  justify-content: center;
  gap: 8px;
  margin: 32px 0 48px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 8px 20px;
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  border: 1px solid var(--border);
  border-radius: 22px;
  color: var(--text-muted);
  background: transparent;
  transition: all 0.3s;
  cursor: pointer;
}

.filter-btn:hover,
.filter-btn.active {
  border-color: var(--gold);
  color: var(--gold);
  background: rgba(201,168,76,0.05);
}

/* ── 앨범 그리드 ── */
.album-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 24px;
  padding: 0 40px 80px;
  max-width: 1400px;
  margin: 0 auto;
}

/* ── 플립 카드 ── */
.album-card {
  perspective: 1000px;
  aspect-ratio: 1;
  cursor: pointer;
  opacity: 0;
  transform: translateY(20px);
}

.album-card.visible {
  opacity: 1;
  transform: translateY(0);
  transition: opacity 0.5s var(--ease-out), transform 0.5s var(--ease-out);
}

.album-card.hidden {
  display: none;
}

.card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.6s var(--ease-in-out);
}

.album-card:hover .card-inner,
.album-card.flipped .card-inner {
  transform: rotateY(180deg);
}

.card-front,
.card-back {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  border-radius: 4px;
  overflow: hidden;
}

/* 앞면 */
.card-front {
  background: var(--bg-card);
}

.card-front img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.6s var(--ease-out);
}

.album-card:hover .card-front img {
  transform: scale(1.04);
}

.card-overlay {
  position: absolute;
  bottom: 0; left: 0; right: 0;
  padding: 16px;
  background: linear-gradient(to top, rgba(0,0,0,0.8) 0%, transparent 100%);
}

.card-year {
  font-size: 0.7rem;
  letter-spacing: 0.2em;
  color: var(--gold);
}

/* 뒷면 */
.card-back {
  background: var(--bg-card2);
  border: 1px solid var(--border);
  transform: rotateY(180deg);
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.card-back h3 {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  color: var(--text);
  line-height: 1.3;
}

.card-year-back {
  font-size: 0.65rem;
  letter-spacing: 0.15em;
  color: var(--gold);
  text-transform: uppercase;
}

.track-list {
  list-style: none;
  flex: 1;
  overflow: hidden;
}

.track-list li {
  font-size: 0.75rem;
  color: var(--text-muted);
  padding: 4px 0;
  border-bottom: 1px solid rgba(255,255,255,0.04);
  display: flex;
  justify-content: space-between;
  gap: 8px;
}

.track-list li span {
  color: var(--text-muted);
  opacity: 0.6;
  font-size: 0.65rem;
  text-align: right;
  flex-shrink: 0;
}

.card-cta {
  font-size: 0.7rem;
  letter-spacing: 0.15em;
  color: var(--gold);
  text-transform: uppercase;
  border-top: 1px solid var(--border);
  padding-top: 10px;
  transition: opacity 0.3s;
}

.card-cta:hover { opacity: 0.7; }