/* ============================================================
   HorizontalScrollCards — components.md #26
   ============================================================ */
.ds-hscroll-title { font-family: var(--font-heading-cn); font-size: 1.4rem; font-weight: 900; margin: 0 0 0.5rem; }
.ds-hscroll-track { display: flex; gap: 24px; overflow-x: auto; scroll-snap-type: x mandatory; padding: 20px 0; -webkit-overflow-scrolling: touch; }
.ds-hscroll-track::-webkit-scrollbar { height: 4px; }
.ds-hscroll-track::-webkit-scrollbar-thumb { background: var(--brand-accent); border-radius: 2px; }
.ds-hscroll-card { min-width: 340px; max-width: 380px; flex-shrink: 0; scroll-snap-align: center; background: var(--surface-card); border-radius: var(--radius-lg); padding: 32px 28px; box-shadow: var(--shadow-md); position: relative; box-sizing: border-box; }
.ds-hscroll-num { position: absolute; top: 16px; right: 20px; font-family: var(--font-hand); font-size: 2rem; color: var(--brand-primary); opacity: 0.3; }
.ds-hscroll-card h3 { font-size: 1.1rem; font-weight: 700; margin: 0 0 12px; font-family: var(--font-heading-cn); }
.ds-hscroll-card p { font-size: 0.82rem; color: var(--text-secondary); line-height: 1.9; margin: 0; }
.ds-hscroll-hint { font-size: 0.75rem; color: var(--text-faint); margin-top: 1rem; font-family: var(--font-hand); }

/* ============================================================
   Accordion — components.md #28
   ============================================================ */
.ds-accordion { max-width: 600px; }
.ds-accordion-item { border-bottom: 1px solid var(--border-hairline-strong); }
.ds-accordion-header { display: flex; align-items: center; gap: 16px; padding: 18px 0; cursor: pointer; transition: all 0.2s; }
.ds-accordion-header:hover { padding-left: 8px; }
.ds-accordion-step { width: 32px; height: 32px; border-radius: 50%; background: var(--brand-primary); color: #fff; font-size: 0.8rem; font-weight: 700; display: flex; align-items: center; justify-content: center; flex-shrink: 0; }
.ds-accordion-header h4 { font-size: 0.95rem; font-weight: 700; margin: 0; flex: 1; }
.ds-accordion-arrow { margin-left: auto; font-size: 0.8rem; color: var(--text-faint); transition: transform 0.2s; }
.ds-accordion-item.open .ds-accordion-arrow { transform: rotate(180deg); }
.ds-accordion-body { padding: 0 0 18px 48px; display: none; }
.ds-accordion-item.open .ds-accordion-body { display: block; animation: ds-tabFadeIn 0.3s; }
.ds-accordion-body p { font-size: 0.82rem; color: var(--text-secondary); line-height: 1.9; margin: 0; }

/* ============================================================
   Carousel — components.md #29
   ============================================================ */
.ds-carousel { position: relative; width: 100%; max-width: 600px; margin: 0 auto; overflow: hidden; }
.ds-carousel-slides { display: flex; transition: transform 0.4s ease; }
.ds-carousel-slide { min-width: 100%; padding: 40px; text-align: center; box-sizing: border-box; }
.ds-carousel-icon { font-size: 2.5rem; margin-bottom: 1rem; }
.ds-carousel-slide h3 { font-size: 1.4rem; font-weight: 700; margin: 0 0 16px; font-family: var(--font-heading-cn); }
.ds-carousel-slide p { font-size: 0.85rem; color: var(--text-secondary); line-height: 2; max-width: 450px; margin: 0 auto; }
.ds-carousel-arrows { display: flex; justify-content: center; gap: 16px; margin-top: 2rem; }
.ds-carousel-arrow { width: 40px; height: 40px; border-radius: 50%; border: 1.5px solid var(--brand-accent); background: transparent; cursor: pointer; font-size: 1rem; color: var(--brand-primary); transition: all 0.2s; }
.ds-carousel-arrow:hover { background: var(--brand-primary); color: #fff; border-color: var(--brand-primary); }
.ds-carousel-dots { display: flex; justify-content: center; gap: 8px; margin-top: 1rem; }
.ds-carousel-dot { width: 8px; height: 8px; border-radius: 50%; background: var(--brand-accent); opacity: 0.4; transition: all 0.2s; display: inline-block; }
.ds-carousel-dot.active { opacity: 1; transform: scale(1.3); background: var(--brand-primary); }

/* ============================================================
   StackedCards — components.md #30 (simplified reorder+transition
   re-interpretation of the source's fly-out-left animation)
   ============================================================ */
.ds-stack-container { position: relative; width: 380px; max-width: 100%; height: 280px; margin: 1.5rem auto; }
.ds-stack-card { position: absolute; inset: 0; background: var(--surface-card); border-radius: var(--radius-lg); padding: 32px; box-shadow: var(--shadow-md); transition: all 0.4s ease; cursor: pointer; box-sizing: border-box; }
.ds-stack-card h3 { font-size: 1.2rem; font-weight: 700; margin: 0 0 12px; font-family: var(--font-heading-cn); }
.ds-stack-card p { font-size: 0.82rem; color: var(--text-secondary); line-height: 1.9; margin: 0; }
.ds-stack-tag { display: inline-block; background: var(--brand-primary); color: #fff; font-size: 0.7rem; padding: 2px 8px; border-radius: 3px; margin-bottom: 10px; }
.ds-stack-hint { font-size: 0.75rem; color: var(--text-faint); text-align: center; margin-top: 1rem; font-family: var(--font-hand); }

/* ============================================================
   FlipCard — components.md #31 (click) + #37 (hover grid item)
   ============================================================ */
.ds-flip-scene { perspective: 1000px; width: 500px; max-width: 90vw; height: 320px; }
.ds-flip-card { width: 100%; height: 100%; position: relative; transform-style: preserve-3d; transition: transform 0.6s ease; cursor: pointer; }
.ds-flip-card.flipped { transform: rotateY(180deg); }
.ds-flip-front, .ds-flip-back { position: absolute; inset: 0; backface-visibility: hidden; border-radius: var(--radius-xl); display: flex; flex-direction: column; justify-content: center; align-items: center; padding: 40px; box-sizing: border-box; text-align: center; }
.ds-flip-front { background: var(--surface-card); box-shadow: var(--shadow-md); }
.ds-flip-front h2 { font-size: clamp(2.2rem, 5vw, 3.2rem); line-height: 1.6; font-family: var(--font-heading-cn); margin: 0; }
.ds-flip-hint { font-size: 0.75rem; color: var(--text-faint); margin-top: 2rem; }
.ds-flip-back { background: var(--brand-primary); color: #fff; transform: rotateY(180deg); }
.ds-flip-back h3 { font-size: 1rem; font-weight: 400; opacity: 0.8; margin: 0 0 1rem; }
.ds-flip-back p { font-size: 0.92rem; line-height: 2; max-width: 380px; margin: 0; }

.ds-flip-hover-scene { aspect-ratio: 3/4; position: relative; cursor: pointer; perspective: 1200px; }
.ds-flip-hover-inner { width: 100%; height: 100%; position: relative; transition: transform 0.6s; transform-style: preserve-3d; border-radius: var(--radius-md); }
.ds-flip-hover-scene:hover .ds-flip-hover-inner { transform: rotateY(180deg); }
.ds-flip-hover-front, .ds-flip-hover-back { position: absolute; inset: 0; backface-visibility: hidden; border-radius: var(--radius-md); overflow: hidden; box-sizing: border-box; }
.ds-flip-hover-front img { width: 100%; height: 100%; object-fit: cover; display: block; }
.ds-flip-hover-label { position: absolute; bottom: 0; left: 0; right: 0; padding: 10px 12px; background: linear-gradient(to top, rgba(0,0,0,.7), transparent); color: #fff; font-size: 0.72rem; font-weight: 600; }
.ds-flip-hover-back { transform: rotateY(180deg); background: var(--color-ink); padding: 20px; display: flex; flex-direction: column; justify-content: center; color: #fff; }

/* ============================================================
   HoverRevealCard — components.md #32
   ============================================================ */
.ds-reveal-card { position: relative; width: 550px; max-width: 100%; text-align: center; padding: 48px 40px; background: var(--surface-card); border-radius: var(--radius-xl); box-shadow: var(--shadow-sm); overflow: hidden; box-sizing: border-box; }
.ds-reveal-text { font-size: clamp(2.5rem, 6vw, 3.5rem); line-height: 1.5; color: var(--text-body); position: relative; z-index: 2; margin: 0; font-family: var(--font-heading-cn); }
.ds-reveal-sub { font-size: 0.8rem; color: var(--text-faint); margin-top: 0.5rem; letter-spacing: 0.1em; position: relative; z-index: 2; }
.ds-reveal-overlay { position: absolute; inset: 0; background: var(--brand-primary); color: #fff; display: flex; flex-direction: column; justify-content: center; align-items: center; padding: 40px; opacity: 0; transition: opacity 0.4s ease; z-index: 3; border-radius: var(--radius-xl); box-sizing: border-box; }
.ds-reveal-card:hover .ds-reveal-overlay { opacity: 1; }
.ds-reveal-overlay p { font-size: 0.9rem; line-height: 2; text-align: center; max-width: 380px; margin: 0; }
.ds-reveal-note { margin-top: 1rem; font-size: 0.82rem; opacity: 0.7; }
.ds-reveal-hint { font-size: 0.75rem; color: var(--text-faint); margin-top: 1rem; text-align: center; }

/* ============================================================
   DarkReveal — components.md #33 (self-contained dark section)
   ============================================================ */
.ds-dark-reveal { position: relative; background: var(--color-dark-panel); color: #f0e9dc; padding: clamp(60px, 10vh, 120px) clamp(24px, 4vw, 60px); display: flex; align-items: center; justify-content: center; overflow: hidden; box-sizing: border-box; min-height: 60vh; }
.ds-dark-reveal-bgchar { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); font-size: clamp(14rem, 30vw, 26rem); color: rgba(255,255,255,.03); pointer-events: none; line-height: 1; font-family: var(--font-heading-cn); font-weight: 900; }
.ds-dark-reveal-content { position: relative; z-index: 1; text-align: center; max-width: 550px; }
.ds-dark-reveal-content h2 { font-size: clamp(2rem, 6vw, 3.2rem); line-height: 1.6; color: #fff; margin: 0 0 2rem; font-family: var(--font-heading-cn); }
.ds-dark-reveal-divider { width: 40px; height: 2px; background: var(--brand-accent); margin: 0 auto 2rem; }
.ds-dark-reveal-trans { font-size: 0.88rem; color: rgba(255,255,255,.6); line-height: 2; opacity: 0; transition: opacity 0.5s; min-height: 1.5em; }
.ds-dark-reveal-trans.show { opacity: 1; }
.ds-dark-reveal-btn { margin-top: 2rem; padding: 8px 20px; border: 1px solid var(--brand-accent); background: transparent; color: var(--brand-accent); border-radius: var(--radius-pill); font-size: 0.78rem; cursor: pointer; transition: all 0.2s; font-family: var(--font-body); }
.ds-dark-reveal-btn:hover { background: var(--brand-accent); color: var(--color-ink); }

/* ============================================================
   Checklist — components.md #35
   ============================================================ */
.ds-checklist { max-width: 550px; }
.ds-checklist-item { display: flex; align-items: flex-start; gap: 14px; padding: 14px 0; border-bottom: 1px solid var(--border-hairline); }
.ds-checklist-check { width: 22px; height: 22px; border-radius: 6px; border: 2px solid var(--brand-accent); flex-shrink: 0; margin-top: 2px; cursor: pointer; transition: all 0.2s; display: flex; align-items: center; justify-content: center; }
.ds-checklist-check.checked { background: var(--brand-primary); border-color: var(--brand-primary); }
.ds-checklist-check.checked::after { content: '✓'; color: #fff; font-size: 0.7rem; }
.ds-checklist-content { flex: 1; }
.ds-checklist-content h4 { font-size: 0.85rem; font-weight: 600; margin: 0 0 2px; }
.ds-checklist-content p { font-size: 0.78rem; color: var(--text-secondary); line-height: 1.7; margin: 0; }
.ds-checklist-tag { display: inline-block; font-size: 0.65rem; background: var(--surface-page-alt); color: var(--text-faint); padding: 2px 8px; border-radius: 3px; margin-top: 4px; }

/* ============================================================
   GalleryRail — components.md #36
   ============================================================ */
.ds-gallery-rail { display: flex; gap: 0; max-width: 850px; height: 420px; border-radius: var(--radius-lg); overflow: hidden; box-shadow: var(--shadow-lg); }
.ds-gallery-thumbs { width: 100px; background: var(--color-ink); display: flex; flex-direction: column; gap: 2px; flex-shrink: 0; overflow-y: auto; }
.ds-gallery-thumbs img { width: 100%; aspect-ratio: 1; object-fit: cover; cursor: pointer; transition: opacity 0.2s; display: block; }
.ds-gallery-main { flex: 1; position: relative; overflow: hidden; }
.ds-gallery-main img { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; transition: opacity 0.4s; }
.ds-gallery-panel { width: 280px; background: var(--surface-card); padding: 28px 20px; overflow-y: auto; flex-shrink: 0; border-left: 1px solid var(--border-hairline); box-sizing: border-box; }
.ds-gallery-panel h3 { font-size: 1rem; font-weight: 800; margin: 0 0 4px; font-family: var(--font-heading-cn); }
.ds-gallery-meta { font-size: 0.72rem; color: var(--brand-primary); font-weight: 600; margin: 0 0 12px; }
.ds-gallery-desc { font-size: 0.78rem; color: var(--text-secondary); line-height: 1.8; margin: 0; }
@media (max-width: 640px) {
  .ds-gallery-rail { flex-direction: column; height: auto; }
  .ds-gallery-thumbs { flex-direction: row; width: 100%; }
  .ds-gallery-panel { width: 100%; }
}