:root {
  --bg-parchment: #e8dfd1;
  --bg-parchment-outer: #d7cab6;
  --bg-panel: rgba(233, 224, 210, 0.78);
  --bg-card: #e5dccd;
  --plum-active: #3f2835;
  --plum-hover: #523546;
  --ink-dark: #2a221d;
  --ink-mid: #54483f;
  --ink-muted: #7c6f62;
  --line-border: #9e907f;
  --line-light: rgba(158, 144, 127, 0.42);
  --font-serif: 'Cinzel', 'Cormorant Garamond', 'Palatino Linotype', Georgia, serif;
  --font-mono: 'IBM Plex Mono', 'Courier New', Courier, monospace;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  width: 100%;
  min-height: 100vh;
  background-color: var(--bg-parchment);
  color: var(--ink-dark);
  font-family: var(--font-mono);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

@media (min-width: 1181px) {
  html, body {
    height: 100vh;
    overflow: hidden;
  }
}

/* =========================================================================
   AGED PARCHMENT BACKGROUND, GRAIN & ARCHITECTURAL DRAFTING GRID
   ========================================================================= */
.parchment-backdrop {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  background:
    radial-gradient(ellipse at 50% 48%, rgba(244, 238, 228, 0.85) 0%, rgba(230, 220, 204, 0.92) 58%, rgba(208, 194, 174, 0.98) 100%);
}

.drafting-grid {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 1;
  background-image:
    linear-gradient(to right, rgba(150, 136, 120, 0.09) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(150, 136, 120, 0.09) 1px, transparent 1px),
    linear-gradient(to right, rgba(150, 136, 120, 0.16) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(150, 136, 120, 0.16) 1px, transparent 1px);
  background-size: 28px 28px, 28px 28px, 140px 140px, 140px 140px;
}

.paper-noise {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 2;
  opacity: 0.28;
  mix-blend-mode: multiply;
}

/* =========================================================================
   OUTER ORNAMENTAL DOUBLE-LINE HERITAGE FRAME & FINIALS
   ========================================================================= */
.sheet-frame {
  position: relative;
  z-index: 5;
  width: calc(100vw - 24px);
  height: calc(100vh - 24px);
  margin: 12px auto;
  border: 1px solid var(--line-border);
  box-shadow: inset 0 0 0 3px var(--bg-parchment), inset 0 0 0 4px var(--line-light);
  display: grid;
  grid-template-columns: 308px 1fr 310px;
  grid-template-rows: 1fr;
  padding: 16px 22px;
  gap: 12px;
}

.corner-ornament {
  position: absolute;
  width: 18px;
  height: 18px;
  pointer-events: none;
  z-index: 10;
}
.corner-ornament.tl { top: -4px; left: -4px; }
.corner-ornament.tr { top: -4px; right: -4px; transform: scaleX(-1); }
.corner-ornament.bl { bottom: -4px; left: -4px; transform: scaleY(-1); }
.corner-ornament.br { bottom: -4px; right: -4px; transform: scale(-1, -1); }

.edge-finial {
  position: absolute;
  pointer-events: none;
  z-index: 10;
  background: var(--bg-parchment);
  display: flex;
  align-items: center;
  justify-content: center;
}
.edge-finial.top {
  top: 1.5px;
  left: 50%;
  transform: translate(-50%, -50%);
  padding: 0 8px;
}
.edge-finial.bottom {
  bottom: 1.5px;
  left: 50%;
  transform: translate(-50%, 50%);
  padding: 0 8px;
}
.edge-finial.left {
  left: 1.5px;
  top: 50%;
  transform: translate(-50%, -50%) rotate(90deg);
  padding: 0 8px;
}
.edge-finial.right {
  right: 1.5px;
  top: 50%;
  transform: translate(50%, -50%) rotate(90deg);
  padding: 0 8px;
}

/* =========================================================================
   LEFT COLUMN: BRANDING, TITLE, EXPLORE, VIEW MODE, CUSTOMIZATION, SPECS
   ========================================================================= */
.col-left {
  position: relative;
  z-index: 15;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 14px;
  height: 100%;
  pointer-events: auto;
  padding-right: 4px;
}

.left-header-group {
  display: flex;
  flex-direction: column;
}

.left-explore-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.left-bottom-group {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.brand-header {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 6px;
}

.brand-logo-svg {
  width: 26px;
  height: 26px;
  flex-shrink: 0;
}

.brand-text-wrap {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.brand-name {
  font-size: 9px;
  font-weight: 600;
  letter-spacing: 0.28em;
  color: var(--ink-dark);
  text-transform: uppercase;
}

.brand-sub {
  font-size: 7.5px;
  font-weight: 400;
  letter-spacing: 0.20em;
  color: var(--ink-muted);
  text-transform: uppercase;
}

.title-divider-svg {
  width: 100%;
  height: 12px;
  margin: 2px 0 7px 0;
  display: block;
}

.hero-title {
  font-family: var(--font-serif);
  font-weight: 600;
  color: var(--ink-dark);
  line-height: 0.96;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  margin-bottom: 9px;
}

.hero-title .line-1 { display: block; font-size: 32px; }
.hero-title .line-2 { display: block; font-size: 28px; margin-top: 2px; }
.hero-title .line-3 { display: block; font-size: 30px; margin-top: 2px; }
.hero-title .init-cap { font-size: 1.16em; }

.subtitle-banner {
  border-top: 1px solid var(--line-border);
  border-bottom: 1px solid var(--line-border);
  padding: 4.5px 0;
  text-align: center;
  font-size: 8.8px;
  font-weight: 500;
  letter-spacing: 0.28em;
  color: var(--ink-mid);
  text-transform: uppercase;
  margin-bottom: 9px;
}

.hero-desc {
  font-size: 9.5px;
  line-height: 1.50;
  color: var(--ink-mid);
  margin-bottom: 0;
}

/* BOXED PANEL SYSTEM */
.arch-box {
  border: 1px solid var(--line-border);
  background: var(--bg-panel);
  position: relative;
  padding: 9px 10px;
  margin-bottom: 0;
}

.arch-box::before,
.arch-box::after {
  content: '';
  position: absolute;
  width: 5px;
  height: 5px;
  border-color: var(--ink-mid);
  pointer-events: none;
}
.arch-box::before {
  top: 2px;
  left: 2px;
  border-top: 1px solid var(--ink-mid);
  border-left: 1px solid var(--ink-mid);
}
.arch-box::after {
  bottom: 2px;
  right: 2px;
  border-bottom: 1px solid var(--ink-mid);
  border-right: 1px solid var(--ink-mid);
}

.box-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 9px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-dark);
  padding-bottom: 6px;
  margin-bottom: 8px;
  border-bottom: 1px solid var(--line-light);
}

.box-header-left {
  display: flex;
  align-items: center;
  gap: 5px;
}

.box-header .diamond-bullet {
  color: var(--plum-active);
  font-size: 9.5px;
}

/* FULL-WIDTH SELF-DRIVE BAR + 3x2 EXPLORE GRID */
.drive-road-btn {
  width: 100%;
  height: 32px;
  margin-bottom: 6px;
  appearance: none;
  background: var(--bg-card);
  border: 1px solid var(--line-border);
  box-shadow: inset 0 0 0 2px var(--bg-parchment), inset 0 0 0 3px rgba(158, 144, 127, 0.30);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 7px;
  cursor: pointer;
  color: var(--ink-dark);
  font-family: var(--font-mono);
  font-size: 8.2px;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  transition: all 0.18s ease;
}

.drive-road-btn svg {
  width: 15px;
  height: 15px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.5;
}

.drive-road-btn:hover {
  border-color: var(--plum-active);
  background: #dfd4c2;
}

.drive-road-btn.active {
  background: var(--plum-active);
  border-color: #291822;
  box-shadow: inset 0 0 0 2px var(--plum-active), inset 0 0 0 3px rgba(232, 223, 209, 0.32);
  color: #f3ece0;
}

.explore-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.action-btn {
  appearance: none;
  background: var(--bg-card);
  border: 1px solid var(--line-border);
  box-shadow: inset 0 0 0 2px var(--bg-parchment), inset 0 0 0 3px rgba(158, 144, 127, 0.30);
  height: 38px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2.5px;
  cursor: pointer;
  color: var(--ink-dark);
  font-family: var(--font-mono);
  font-size: 7.6px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  transition: all 0.18s ease;
  padding: 3px;
}

.action-btn svg {
  width: 16px;
  height: 16px;
  stroke: currentColor;
  fill: none;
  stroke-width: 1.4;
}

.action-btn:hover {
  border-color: var(--plum-active);
  background: #dfd4c2;
}

.action-btn.active {
  background: var(--plum-active);
  border-color: #291822;
  box-shadow: inset 0 0 0 2px var(--plum-active), inset 0 0 0 3px rgba(232, 223, 209, 0.32);
  color: #f3ece0;
}

/* VIEW MODE SECTION (ISO, SIDE, FRONT, REAR) */
.view-mode-section {
  margin-bottom: 0;
}

.section-line-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 6px;
}

.section-line-header span {
  font-size: 9px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-dark);
  white-space: nowrap;
}

.section-line-header .h-line {
  flex: 1;
  height: 1px;
  background: var(--line-border);
  position: relative;
}
.section-line-header .h-line::after {
  content: '◇';
  position: absolute;
  right: -2px;
  top: -6px;
  font-size: 9px;
  color: var(--ink-mid);
}

.view-mode-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px;
}

.view-card {
  appearance: none;
  background: var(--bg-card);
  border: 1px solid var(--line-border);
  padding: 4px 3px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  height: 58px;
  cursor: pointer;
  color: var(--ink-dark);
  font-family: var(--font-mono);
  font-size: 8px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  transition: all 0.16s ease;
}

.view-card img {
  width: 100%;
  height: 34px;
  object-fit: contain;
  pointer-events: none;
}

.view-card:hover {
  border-color: var(--plum-active);
  background: #dfd4c2;
}

.view-card.active {
  background: var(--plum-active);
  border-color: #291822;
  box-shadow: inset 0 0 0 2px var(--plum-active), inset 0 0 0 3px rgba(232, 223, 209, 0.28);
  color: #f3ece0;
}

/* =========================================================================
   BESPOKE CARRIAGE CUSTOMIZATION LAUNCHER & FLOATING BOTTOM ATELIER DOCK
   ========================================================================= */
.reset-btn {
  appearance: none;
  background: var(--bg-card);
  border: 1px solid var(--line-border);
  padding: 2.5px 7px;
  font-family: var(--font-mono);
  font-size: 7.5px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-dark);
  cursor: pointer;
  transition: all 0.15s ease;
}
.reset-btn:hover {
  background: var(--plum-active);
  border-color: var(--plum-active);
  color: #f3ece0;
}

/* LEFT-SIDEBAR BESPOKE ATELIER CARD & 1-CLICK THEME PRESETS */
.preset-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 5px;
  margin-bottom: 7px;
}

.preset-chip {
  appearance: none;
  background: var(--bg-card);
  border: 1px solid var(--line-border);
  padding: 5px 6px;
  display: flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 7.4px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-dark);
  transition: all 0.15s ease;
  text-align: left;
}

.preset-chip:hover {
  border-color: var(--plum-active);
  background: #dfd4c2;
}

.preset-chip.active {
  background: var(--plum-active);
  border-color: #291822;
  color: #f3ece0;
}

.preset-dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
  border: 1px solid rgba(255, 255, 255, 0.45);
  box-shadow: 0 0 0 1px rgba(42, 34, 29, 0.45);
  flex-shrink: 0;
}

.atelier-launcher-summary {
  font-size: 7.4px;
  line-height: 1.4;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-mid);
  margin-bottom: 7px;
  padding: 4px 6px;
  background: rgba(216, 206, 190, 0.42);
  border: 1px dashed var(--line-border);
  text-align: center;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.atelier-open-btn {
  width: 100%;
  height: 31px;
  appearance: none;
  background: var(--bg-card);
  border: 1px solid var(--line-border);
  box-shadow: inset 0 0 0 2px var(--bg-parchment), inset 0 0 0 3px rgba(158, 144, 127, 0.30);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  cursor: pointer;
  color: var(--ink-dark);
  font-family: var(--font-mono);
  font-size: 7.8px;
  font-weight: 600;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  transition: all 0.18s ease;
}

.atelier-open-btn:hover {
  border-color: var(--plum-active);
  background: #dfd4c2;
}

.atelier-open-btn.active {
  background: var(--plum-active);
  border-color: #291822;
  box-shadow: inset 0 0 0 2px var(--plum-active), inset 0 0 0 3px rgba(232, 223, 209, 0.32);
  color: #f3ece0;
}

/* FLOATING BOTTOM ARCHITECTURAL CONFIGURATOR DOCK (REFINED UX) */
.atelier-dock {
  position: absolute;
  bottom: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: min(97%, 810px);
  z-index: 28;
  background: rgba(236, 229, 216, 0.97);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--ink-mid);
  box-shadow: 0 10px 32px rgba(32, 24, 18, 0.24), inset 0 0 0 2px var(--bg-parchment), inset 0 0 0 3px var(--line-light);
  padding: 9px 13px 11px 13px;
  transition: all 0.22s cubic-bezier(0.22, 1, 0.36, 1);
}

/* When collapsed, it remains a sleek, unobtrusive Quick-Tab Pill Bar at the bottom center! */
.atelier-dock.collapsed {
  padding: 6px 10px;
  width: auto;
  max-width: 96%;
}

.atelier-dock.collapsed .atelier-dock-body {
  display: none;
}

.atelier-dock.collapsed .atelier-tab-btn.active {
  background: var(--bg-card);
  color: var(--ink-dark);
  border-color: var(--line-border);
}

.atelier-dock-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  flex-wrap: nowrap;
}

.atelier-dock:not(.collapsed) .atelier-dock-bar {
  padding-bottom: 7px;
  margin-bottom: 9px;
  border-bottom: 1px solid var(--line-border);
}

.atelier-dock-title {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 8.5px;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--ink-dark);
  cursor: pointer;
  user-select: none;
  white-space: nowrap;
}

.atelier-dock-title .diamond-bullet {
  color: var(--plum-active);
  font-size: 10px;
}

.atelier-tabs-row {
  display: flex;
  align-items: center;
  gap: 5px;
}

.atelier-tab-btn {
  appearance: none;
  background: var(--bg-card);
  border: 1px solid var(--line-border);
  padding: 4.5px 10px;
  font-family: var(--font-mono);
  font-size: 7.8px;
  font-weight: 600;
  letter-spacing: 0.10em;
  text-transform: uppercase;
  color: var(--ink-mid);
  cursor: pointer;
  transition: all 0.15s ease;
  white-space: nowrap;
}

.atelier-tab-btn:hover {
  border-color: var(--plum-active);
  color: var(--ink-dark);
  background: #dfd4c2;
}

.atelier-tab-btn.active {
  background: var(--plum-active);
  border-color: #291822;
  color: #f3ece0;
  box-shadow: 0 1px 4px rgba(41, 24, 34, 0.22);
}

.atelier-dock-actions {
  display: flex;
  align-items: center;
  gap: 5px;
  white-space: nowrap;
}

.atelier-tab-pane {
  display: none;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  align-items: stretch;
}

.atelier-tab-pane.active {
  display: grid;
}

/* Grouped Sub-Cards inside each tab for clear visual hierarchy */
.atelier-subcard {
  background: rgba(218, 208, 192, 0.45);
  border: 1px solid var(--line-border);
  padding: 8px 11px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  gap: 7px;
}

.subcard-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px dashed rgba(158, 144, 127, 0.55);
  padding-bottom: 4px;
  margin-bottom: 1px;
}

.subcard-title {
  font-size: 7.6px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--ink-dark);
}

.subcard-hint {
  font-size: 6.8px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

.custom-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 10px;
  min-height: 24px;
}

.custom-label-stack {
  display: flex;
  align-items: baseline;
  gap: 6px;
  min-width: 0;
}

.custom-label {
  font-size: 8px;
  font-weight: 600;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--ink-dark);
  white-space: nowrap;
}

.custom-subval {
  font-size: 7.3px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--plum-active);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.color-pills {
  display: flex;
  align-items: center;
  gap: 6px;
}

.color-pill {
  width: 20px;
  height: 20px;
  border-radius: 3px;
  border: 1px solid rgba(42, 34, 29, 0.60);
  cursor: pointer;
  position: relative;
  transition: transform 0.14s ease, box-shadow 0.14s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

.color-pill:hover {
  transform: scale(1.13);
}

.color-pill.active {
  border-color: var(--ink-dark);
  box-shadow: 0 0 0 1.5px var(--bg-parchment), 0 0 0 3px var(--plum-active);
}

.color-pill.active::after {
  content: '';
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: #f5efe4;
  box-shadow: 0 0 2px rgba(0, 0, 0, 0.75);
}

.seg-pills {
  display: flex;
  align-items: center;
  gap: 4px;
}

.seg-pill {
  appearance: none;
  background: var(--bg-card);
  border: 1px solid var(--line-border);
  padding: 3.5px 7.5px;
  font-family: var(--font-mono);
  font-size: 7.4px;
  font-weight: 600;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--ink-dark);
  cursor: pointer;
  transition: all 0.14s ease;
  white-space: nowrap;
}

.seg-pill:hover {
  border-color: var(--plum-active);
  background: #dfd4c2;
}

.seg-pill.active {
  background: var(--plum-active);
  border-color: #291822;
  color: #f3ece0;
}

.dim-slider-wrap {
  display: flex;
  align-items: center;
  gap: 8px;
  flex: 1;
  justify-content: flex-end;
}

.dim-slider {
  -webkit-appearance: none;
  appearance: none;
  width: 118px;
  height: 4px;
  background: rgba(158, 144, 127, 0.65);
  border-radius: 2px;
  outline: none;
  cursor: pointer;
}

.dim-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 12px;
  height: 12px;
  background: var(--plum-active);
  border: 1.5px solid var(--bg-parchment);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.35), 0 0 0 1px var(--ink-dark);
  border-radius: 2px;
  cursor: grab;
  transition: transform 0.12s ease;
}

.dim-slider::-webkit-slider-thumb:hover {
  transform: scale(1.18);
}

.dim-val-badge {
  font-family: var(--font-mono);
  font-size: 7.6px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--ink-dark);
  background: rgba(232, 223, 209, 0.75);
  border: 1px solid rgba(158, 144, 127, 0.55);
  padding: 2px 5px;
  min-width: 54px;
  text-align: right;
  white-space: nowrap;
  cursor: pointer;
  transition: all 0.14s ease;
}

.dim-val-badge:hover {
  border-color: var(--plum-active);
  background: #dfd4c2;
}

/* BOTTOM-LEFT TECHNICAL SPECS TABLE */
.specs-table {
  border-top: 1px solid var(--line-border);
  padding-top: 4px;
}

.spec-row {
  display: grid;
  grid-template-columns: 88px 1fr;
  padding: 3.5px 2px;
  border-bottom: 1px solid var(--line-light);
  font-size: 8.2px;
  letter-spacing: 0.15em;
  text-transform: uppercase;
}

.spec-row .spec-key { color: var(--ink-muted); }
.spec-row .spec-val { color: var(--ink-dark); font-weight: 600; }

/* =========================================================================
   CENTER STAGE: INTERACTIVE 3D CARRIAGE + DIMENSION LINES + 4 CALLOUTS
   ========================================================================= */
.col-center {
  position: relative;
  width: 100%;
  height: 100%;
  min-height: 540px;
  display: flex;
  align-items: center;
  justify-content: center;
}

#carriage-canvas-wrap {
  position: absolute;
  inset: 0;
  z-index: 4;
}

#carriage-canvas {
  width: 100%;
  height: 100%;
  display: block;
  cursor: grab;
}
#carriage-canvas:active {
  cursor: grabbing;
}

#annotation-svg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 8;
  overflow: visible;
}

.callout-item {
  position: absolute;
  z-index: 12;
  display: flex;
  align-items: flex-start;
  gap: 8px;
  cursor: pointer;
  pointer-events: auto;
  transition: transform 0.18s ease;
  max-width: 215px;
}

.callout-item:hover {
  transform: translateY(-1px);
}

.callout-badge {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  border: 1.2px solid var(--ink-dark);
  background: var(--bg-parchment);
  color: var(--ink-dark);
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 600;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 2px 6px rgba(42, 34, 29, 0.12);
  transition: all 0.18s ease;
}

.callout-item:hover .callout-badge,
.callout-item.active .callout-badge {
  background: var(--plum-active);
  border-color: var(--plum-active);
  color: #f3ece0;
}

.callout-text h4 {
  font-size: 9.5px;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-dark);
  margin-bottom: 2px;
}

.callout-text p {
  font-size: 9px;
  line-height: 1.38;
  color: var(--ink-mid);
}

#callout-1 { top: 6.5%; left: 2.0%; }
#callout-2 { top: 66.0%; left: 2.0%; }
#callout-3 { top: 24.0%; right: 1.5%; }
#callout-4 { top: 68.0%; right: 1.5%; }

/* =========================================================================
   RIGHT COLUMN: TECHNICAL ELEVATIONS & MATERIALS / DETAILS SWATCHES
   ========================================================================= */
.col-right {
  position: relative;
  z-index: 15;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  height: 100%;
  pointer-events: auto;
}

.elevations-box {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  margin-bottom: 10px;
  padding: 10px 12px;
}

.elevation-plate {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  cursor: pointer;
  padding: 2px 0;
  transition: opacity 0.16s ease;
}
.elevation-plate:hover {
  opacity: 0.85;
}

.elevation-drawing-wrap {
  position: relative;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  border-bottom: 1px solid rgba(110, 98, 86, 0.35);
  padding-bottom: 2px;
}

.elevation-drawing-wrap::before,
.elevation-drawing-wrap::after {
  content: '';
  position: absolute;
  top: 4px;
  bottom: 0;
  width: 1px;
  background: rgba(110, 125, 135, 0.28);
  pointer-events: none;
}
.elevation-drawing-wrap::before { left: 12%; }
.elevation-drawing-wrap::after { right: 12%; }

.elev-img-side {
  width: 88%;
  max-height: 132px;
  object-fit: contain;
  display: block;
}

.elev-img-front,
.elev-img-rear {
  width: 58%;
  max-height: 136px;
  object-fit: contain;
  display: block;
}

.elev-dim-bar {
  width: 78%;
  display: flex;
  flex-direction: column;
  align-items: center;
  margin-top: 3px;
}

.elev-caption {
  font-size: 7.5px;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-mid);
  margin-bottom: 2px;
}

.elev-mm {
  font-size: 8px;
  font-weight: 600;
  letter-spacing: 0.16em;
  color: var(--ink-dark);
  margin-top: 1px;
}

.front-vert-dim {
  position: absolute;
  left: 11%;
  top: 6%;
  bottom: 8%;
  width: 16px;
  border-left: 1px solid var(--ink-mid);
  border-top: 1px solid rgba(110, 98, 86, 0.4);
  border-bottom: 1px solid rgba(110, 98, 86, 0.4);
  display: flex;
  align-items: center;
  justify-content: center;
}

.front-vert-dim span {
  writing-mode: vertical-rl;
  transform: rotate(180deg);
  font-size: 7.5px;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--ink-dark);
  background: var(--bg-parchment);
  padding: 3px 1px;
  margin-left: -14px;
}

/* MATERIALS & DETAILS BOX (BOTTOM RIGHT) */
.materials-box {
  margin-bottom: 0;
  padding: 9px 10px;
}

.swatches-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 7px;
}

.swatch-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  cursor: pointer;
  transition: transform 0.15s ease;
}
.swatch-item:hover {
  transform: translateY(-2px);
}

.swatch-frame {
  width: 100%;
  aspect-ratio: 1 / 1;
  border: 1px solid var(--line-border);
  padding: 2px;
  background: var(--bg-card);
  box-shadow: 0 2px 5px rgba(42, 34, 29, 0.10);
  margin-bottom: 5px;
}

.swatch-item.active .swatch-frame {
  border-color: var(--plum-active);
  box-shadow: 0 0 0 1.5px var(--plum-active);
}

.swatch-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.swatch-label {
  font-size: 6.8px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-mid);
  text-align: center;
  line-height: 1.2;
  white-space: nowrap;
}

#loading-banner {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 30;
  background: rgba(232, 223, 209, 0.94);
  border: 1px solid var(--line-border);
  padding: 12px 22px;
  font-size: 10px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-dark);
  box-shadow: 0 8px 24px rgba(42, 34, 29, 0.14);
  transition: opacity 0.35s ease;
}
#loading-banner.hidden {
  opacity: 0;
  pointer-events: none;
}

/* =========================================================================
   RESPONSIVE BREAKPOINTS (TABLET & MOBILE)
   ========================================================================= */
@media (max-width: 1180px) {
  .sheet-frame {
    height: auto;
    min-height: calc(100vh - 24px);
    grid-template-columns: 1fr 1fr;
    grid-template-rows: auto auto;
    gap: 18px;
    padding: 20px;
  }
  .col-center {
    grid-column: 1 / -1;
    order: -1;
    height: 540px;
  }
  #carriage-canvas-wrap {
    inset: 0;
  }
}

@media (max-width: 760px) {
  .sheet-frame {
    width: calc(100vw - 16px);
    margin: 8px auto;
    padding: 14px;
    grid-template-columns: 1fr;
  }
  .col-center {
    height: 430px;
    min-height: 430px;
  }
  .callout-item {
    max-width: 155px;
  }
  .callout-text p {
    display: none;
  }
  #callout-1 { top: 4%; left: 2%; }
  #callout-2 { top: 68%; left: 2%; }
  #callout-3 { top: 22%; right: 2%; }
  #callout-4 { top: 70%; right: 2%; }
}