/* ============================================================
   VISION BOOK — dedicated immersive experience
   Reuses design tokens (:root) and base type/reset from styles.css
   ============================================================ */

.vb-app-body {
  margin: 0;
  background: var(--linen);
  color: var(--olive-black);
}
.vb-app { min-height: 100vh; }

/* ============================================================
   SIDEBAR NAVIGATION (desktop)
   ============================================================ */
.vb-sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 272px;
  display: flex;
  flex-direction: column;
  padding: 2.5rem 2rem;
  background: var(--linen);
  border-right: 1px solid var(--limestone);
  z-index: 50;
}
.vb-sidebar-top { margin-bottom: 3.5rem; }
.vb-sidebar-logo {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-serif);
  font-size: 1.05rem;
  letter-spacing: 0.14em;
  color: var(--olive-black);
  margin-bottom: 0.9rem;
}
.vb-sidebar-logo img { width: 24px; height: 24px; object-fit: contain; flex-shrink: 0; }
.vb-sidebar-subtitle {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--olive);
}
.vb-sidebar-nav { display: flex; flex-direction: column; gap: 1.5rem; flex: 1; }
.vb-sidebar-nav a {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 0.84rem;
  color: var(--walnut);
  transition: color var(--transition-fast);
}
.vb-nav-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  border: 1px solid var(--limestone);
  flex-shrink: 0;
  transition: background var(--transition-fast), border-color var(--transition-fast), transform var(--transition-fast);
}
.vb-sidebar-nav a:hover { color: var(--olive-black); }
.vb-sidebar-nav a.is-active { color: var(--olive-black); font-weight: 600; }
.vb-sidebar-nav a.is-active .vb-nav-dot {
  background: var(--olive);
  border-color: var(--olive);
  transform: scale(1.4);
}
.vb-sidebar-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.76rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--olive-black);
  padding-top: 1.5rem;
  margin-top: 1.5rem;
  border-top: 1px solid var(--limestone);
  transition: gap var(--transition-fast);
}
.vb-sidebar-cta:hover { gap: 0.9rem; }

/* ============================================================
   MOBILE TOP BAR + NAV (hidden on desktop)
   ============================================================ */
.vb-mobile-bar { display: none; }
.vb-mobile-nav { display: none; }

/* ============================================================
   MAIN CONTENT SHELL
   ============================================================ */
.vb-main { margin-left: 272px; }
.vb-chapter {
  min-height: 100vh;
  padding: clamp(3.5rem, 7vw, 6rem) clamp(2.5rem, 5.5vw, 5.5rem);
  display: flex;
  flex-direction: column;
  justify-content: center;
  border-bottom: 1px solid var(--limestone);
}
.vb-chapter-index {
  display: block;
  font-family: var(--font-serif);
  font-size: 0.85rem;
  letter-spacing: 0.2em;
  color: var(--mushroom);
  margin-bottom: 1.25rem;
}
.vb-chapter-head { max-width: 640px; margin-bottom: clamp(3rem, 6vw, 5rem); }
.vb-chapter-head .rule { margin: 1.25rem 0 1.5rem; }
.vb-chapter-head .body-text { max-width: 34rem; }
.vb-drag-hint {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: 1.5rem;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--olive);
}

/* ============================================================
   CHAPTER 01 — OVERVIEW (HERO)
   ============================================================ */
.vb-chapter--hero {
  flex-direction: row;
  align-items: stretch;
  gap: clamp(2rem, 4vw, 4rem);
  padding: 0;
}
.vb-hero-content {
  flex: 0 0 36%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: clamp(2rem, 4vw, 4rem);
}
.vb-hero-content h1 { margin-bottom: 0; }
.vb-hero-content .rule { margin: 1.5rem 0; }
.vb-hero-media { flex: 1; overflow: hidden; }
.vb-hero-media img { width: 100%; height: 100%; object-fit: cover; }

/* ============================================================
   CHAPTER 02 — CHAPTER PREVIEW CAROUSEL
   ============================================================ */
.vb-preview-carousel {
  position: relative;
  overflow: hidden;
}
.vb-preview-track {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 2vw, 1.75rem);
  cursor: grab;
  touch-action: pan-y;
  will-change: transform;
  transition: transform 0.5s var(--ease);
}
.vb-preview-track.is-dragging { transition: none; cursor: grabbing; }
.vb-preview-card {
  flex: 0 0 clamp(210px, 25vw, 320px);
  opacity: 0.35;
  transform: scale(0.86);
  transition: opacity 0.4s var(--ease), transform 0.4s var(--ease);
}
.vb-preview-card.is-active { opacity: 1; transform: scale(1); }
.vb-preview-card-media {
  aspect-ratio: 3 / 4;
  overflow: hidden;
  margin-bottom: 1.25rem;
  box-shadow: 0 24px 48px -24px rgba(45, 48, 38, 0.3);
}
.vb-preview-card-media img { width: 100%; height: 100%; object-fit: cover; pointer-events: none; user-select: none; }
.vb-preview-caption { text-align: center; }
.vb-preview-num {
  display: block;
  font-family: var(--font-serif);
  font-size: 0.85rem;
  color: var(--mushroom);
  margin-bottom: 0.5rem;
}
.vb-preview-caption h3 { font-size: 1.1rem; margin-bottom: 0.5rem; }
.vb-preview-caption p { font-size: 0.85rem; color: var(--walnut); max-width: 20rem; margin: 0 auto; }
.vb-preview-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 2;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  border: 1px solid var(--limestone);
  background: var(--linen);
  color: var(--olive-black);
  transition: background var(--transition-fast), border-color var(--transition-fast), color var(--transition-fast);
}
.vb-preview-arrow--prev { left: 0; }
.vb-preview-arrow--next { right: 0; }
.vb-preview-arrow svg { width: 18px; height: 18px; }
.vb-preview-arrow:hover { background: var(--olive-black); border-color: var(--olive-black); color: var(--soft-white); }
.vb-preview-dots { display: flex; justify-content: center; gap: 0.55rem; margin-top: 2.5rem; }
.vb-preview-dots button {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--limestone);
  border: none;
  padding: 0;
  cursor: pointer;
  transition: background 0.2s, transform 0.2s;
}
.vb-preview-dots button.is-active { background: var(--olive-black); transform: scale(1.5); }

/* ============================================================
   CHAPTER 03 — EXPLORE A VISION BOOK (room grid + expanding panel)
   ============================================================ */
.vb-room-grid {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: 1rem;
}
.vb-room-tile {
  position: relative;
  aspect-ratio: 3 / 3.6;
  overflow: hidden;
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
}
.vb-room-tile img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 1s var(--ease), filter 0.3s var(--ease);
  filter: brightness(0.72);
}
.vb-room-tile span {
  position: absolute;
  left: 0.85rem;
  right: 0.85rem;
  bottom: 0.85rem;
  color: var(--soft-white);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  text-align: left;
}
.vb-room-tile:hover img { transform: scale(1.06); filter: brightness(0.6); }
.vb-room-tile.is-active { box-shadow: 0 0 0 2px var(--olive-black); }
.vb-room-tile.is-active img { filter: brightness(0.55); }

.vb-room-panel-wrap {
  margin-top: 2rem;
  background: var(--soft-white);
  box-shadow: 0 30px 60px -30px rgba(45, 48, 38, 0.3);
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.35s var(--ease), transform 0.35s var(--ease);
}
.vb-room-panel-wrap.is-visible { opacity: 1; transform: translateY(0); }
.vb-room-panel-inner { position: relative; display: grid; grid-template-columns: 0.85fr 1.15fr; }
.vb-room-panel-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 1px solid var(--limestone);
  background: var(--soft-white);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--olive-black);
  z-index: 2;
  transition: background var(--transition-fast), color var(--transition-fast);
}
.vb-room-panel-close svg { width: 16px; height: 16px; }
.vb-room-panel-close:hover { background: var(--olive-black); color: var(--soft-white); }
.vb-room-panel-media { overflow: hidden; min-height: 420px; }
.vb-room-panel-media img { width: 100%; height: 100%; object-fit: cover; transition: opacity 0.2s var(--ease); }
.vb-room-panel-media img.vb-fading { opacity: 0; }
.vb-room-panel-content { padding: clamp(2rem, 4vw, 3.5rem); }

.vb-room-detail { display: none; }
.vb-room-detail.is-active { display: block; animation: vbFadeUp 0.4s var(--ease); }
@keyframes vbFadeUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}
.vb-room-detail h3 { margin-bottom: 1rem; }
.vb-room-detail .body-text { max-width: none; }
.vb-room-detail-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem 2rem;
  margin-top: 2rem;
}
.vb-room-detail-grid h4 {
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--olive);
  margin-bottom: 0.6rem;
}
.vb-room-detail-grid ul { display: flex; flex-direction: column; gap: 0.4rem; }
.vb-room-detail-grid li { font-size: 0.9rem; color: var(--walnut); padding-left: 0.9rem; position: relative; }
.vb-room-detail-grid li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.5em;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--olive);
}
.vb-room-detail-grid p { font-size: 0.9rem; color: var(--walnut); }

/* Optional concept-to-reality slider, nested inside a room detail (e.g. Living Room) */
.vb-room-slider { margin-top: 2rem; }
.vb-slider-label {
  font-size: 0.74rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--olive);
  margin-bottom: 0.9rem;
}
.vb-slider-stage {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  cursor: ew-resize;
  user-select: none;
  box-shadow: 0 20px 40px -24px rgba(45, 48, 38, 0.3);
  touch-action: pan-y;
}
.vb-slider-img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  pointer-events: none;
}
.vb-slider-after-wrap { position: absolute; inset: 0; width: 50%; overflow: hidden; }
.vb-slider-after-wrap .vb-slider-img { top: 0; left: 0; right: auto; bottom: 0; width: auto; max-width: none; }
.vb-slider-handle {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 2px;
  background: var(--soft-white);
  transform: translateX(-50%);
}
.vb-slider-handle-grip {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--soft-white);
  color: var(--olive-black);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 8px 20px rgba(45, 48, 38, 0.25);
}
.vb-slider-handle-grip svg { width: 18px; height: 18px; }
.vb-slider-tag {
  position: absolute;
  bottom: 0.85rem;
  font-size: 0.66rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--soft-white);
  background: rgba(20, 18, 12, 0.55);
  padding: 0.4rem 0.75rem;
  pointer-events: none;
}
.vb-slider-tag--before { left: 0.85rem; }
.vb-slider-tag--after { right: 0.85rem; }

/* ============================================================
   CHAPTER 04 — DOWNLOAD
   ============================================================ */
.vb-chapter--download {
  flex-direction: row;
  align-items: center;
  gap: clamp(2rem, 5vw, 4rem);
}
.vb-download-content { flex: 1; }
.vb-download-content h2 { margin-bottom: 2rem; }
.vb-download-actions { display: flex; gap: 1.25rem; flex-wrap: wrap; }
.vb-download-media { flex: 0 0 40%; }
.vb-download-media img {
  width: 100%;
  height: auto;
  display: block;
  box-shadow: 0 40px 80px -40px rgba(45, 48, 38, 0.4);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 980px) {
  .vb-sidebar { display: none; }
  .vb-main { margin-left: 0; padding-top: 64px; }

  .vb-mobile-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 64px;
    padding: 0 1.5rem;
    background: rgba(248, 243, 236, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--limestone);
    z-index: 200;
  }
  .vb-mobile-logo {
    display: flex;
    align-items: center;
    gap: 0.55rem;
    font-family: var(--font-serif);
    font-size: 0.95rem;
    letter-spacing: 0.08em;
    color: var(--olive-black);
  }
  .vb-mobile-toggle {
    width: 36px;
    height: 36px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    background: none;
    border: none;
    padding: 0;
  }
  .vb-mobile-toggle span { display: block; height: 1px; background: var(--olive-black); margin: 0 auto; width: 20px; }

  .vb-mobile-nav {
    display: flex;
    flex-direction: column;
    position: fixed;
    inset: 64px 0 0 0;
    background: var(--linen);
    padding: 2rem 1.5rem;
    gap: 1.1rem;
    transform: translateY(-8px);
    opacity: 0;
    visibility: hidden;
    transition: opacity var(--transition-med), transform var(--transition-med), visibility var(--transition-med);
    z-index: 150;
    overflow-y: auto;
  }
  .vb-mobile-nav.is-open { opacity: 1; transform: translateY(0); visibility: visible; }
  .vb-mobile-nav a { font-family: var(--font-serif); font-size: 1.15rem; color: var(--olive-black); }
  .vb-mobile-nav a.is-active { color: var(--olive); }
  .vb-mobile-cta {
    margin-top: 1rem;
    font-family: var(--font-sans);
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--olive);
  }

  .vb-chapter { min-height: auto; padding: clamp(3rem, 8vw, 4rem) 1.5rem; }
  .vb-chapter--hero { flex-direction: column-reverse; }
  .vb-hero-content { flex: none; padding: 2rem 0 0; }
  .vb-hero-media { min-height: 320px; }
  .vb-room-grid { grid-template-columns: repeat(3, 1fr); }
  .vb-room-panel-inner { grid-template-columns: 1fr; }
  .vb-room-panel-media { min-height: 300px; }
  .vb-chapter--download { flex-direction: column-reverse; }
  .vb-download-media { flex: none; max-width: 360px; }
}

@media (max-width: 640px) {
  .vb-room-grid { grid-template-columns: repeat(2, 1fr); }
  .vb-room-detail-grid { grid-template-columns: 1fr; }
  .vb-slider-handle-grip { width: 36px; height: 36px; }
  .vb-preview-card { flex-basis: 72vw; }
}