:root {
  --bg: #0a0f14;
  --panel: #111820;
  --panel-2: #151f29;
  --panel-3: #0e151c;
  --line: #263342;
  --text: #edf3f8;
  --muted: #8fa0b0;
  --accent: #ffb24a;
  --accent-2: #71c8ff;
  --success: #62d7a5;
  --danger: #ff7b7b;
  --shadow: 0 18px 55px rgba(0,0,0,.28);
}
* { box-sizing: border-box; }
html, body { width: 100%; height: 100%; margin: 0; }
body {
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: radial-gradient(circle at 25% 0%, #16202b 0, #0a0f14 36%, #06090d 100%);
  color: var(--text);
  overflow: hidden;
}
button, input, select { font: inherit; }
button { color: inherit; }
.app-shell { height: 100dvh; display: flex; flex-direction: column; min-height: 0; }
.topbar {
  min-height: 84px;
  padding: 14px 20px;
  border-bottom: 1px solid var(--line);
  background: rgba(10,15,20,.92);
  backdrop-filter: blur(18px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}
.brand-block { min-width: 0; }
.eyebrow { color: var(--muted); font-size: 10px; font-weight: 800; letter-spacing: .16em; text-transform: uppercase; }
.title-row { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; margin-top: 5px; }
h1 { margin: 0; min-width: 0; font-size: clamp(20px, 2.2vw, 30px); letter-spacing: -.03em; font-weight: 700; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.badge { border: 1px solid var(--line); background: var(--panel-2); border-radius: 999px; color: var(--muted); font-size: 11px; font-weight: 800; padding: 5px 9px; white-space: nowrap; }
.top-actions { display: flex; align-items: center; gap: 10px; }
.field { display: flex; flex-direction: column; gap: 5px; color: var(--muted); font-size: 11px; font-weight: 700; }
.field select { min-width: 210px; }
select, input[type="search"] {
  color: var(--text);
  background: var(--panel-2);
  border: 1px solid var(--line);
  border-radius: 9px;
  padding: 9px 11px;
  outline: none;
}
select:focus, input[type="search"]:focus { border-color: #4a647f; box-shadow: 0 0 0 3px rgba(113,200,255,.08); }
.ghost-button, .tool-button, .primary-action, .secondary-action {
  border: 1px solid var(--line);
  background: var(--panel-2);
  border-radius: 9px;
  padding: 9px 12px;
  cursor: pointer;
  transition: .18s ease;
}
.ghost-button:hover, .tool-button:hover:not(:disabled), .secondary-action:hover { border-color: #4b6177; background: #1a2733; }
.tool-button:disabled { opacity: .35; cursor: default; }
.tool-button.primary, .primary-action { background: var(--accent); color: #211300; border-color: var(--accent); font-weight: 800; }
.workspace { flex: 1; display: grid; grid-template-columns: minmax(0, 1fr) 390px; min-height: 0; }
.viewer-panel { min-width: 0; min-height: 0; display: flex; flex-direction: column; background: linear-gradient(180deg, #0e151c, #0a1016); }
.viewer-toolbar, .viewer-footer {
  min-height: 56px;
  border-bottom: 1px solid var(--line);
  padding: 9px 14px;
  display: flex;
  align-items: center;
  gap: 10px;
  background: rgba(14,21,28,.92);
}
.viewer-footer { border-top: 1px solid var(--line); border-bottom: 0; justify-content: space-between; }
.metric { display: flex; flex-direction: column; min-width: 92px; padding-right: 12px; border-right: 1px solid var(--line); }
.metric span { color: var(--muted); font-size: 10px; text-transform: uppercase; letter-spacing: .09em; font-weight: 800; }
.metric strong { font-size: 13px; margin-top: 2px; max-width: 170px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.toolbar-spacer { flex: 1; }
.viewer-canvas-wrap { position: relative; flex: 1; min-height: 0; overflow: hidden; background: radial-gradient(circle at 50% 44%, #1b2732 0%, #111820 42%, #0b1117 100%); }
.viewer-canvas-wrap canvas { display: block; width: 100%; height: 100%; outline: none; }
.viewer-help { position: absolute; left: 14px; top: 13px; z-index: 2; color: #91a3b4; font-size: 11px; padding: 7px 9px; border: 1px solid rgba(255,255,255,.08); border-radius: 8px; background: rgba(8,12,16,.58); pointer-events: none; }
.hotspot { position: absolute; z-index: 5; display: flex; align-items: center; gap: 8px; pointer-events: none; transform: translate(10px,-50%); }
.hotspot.hidden { display: none; }
.hotspot-dot { width: 9px; height: 9px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 5px rgba(255,178,74,.12); }
.hotspot-card { display: flex; flex-direction: column; gap: 2px; padding: 7px 9px; border: 1px solid #526273; border-radius: 8px; background: rgba(8,12,16,.92); box-shadow: var(--shadow); min-width: 130px; }
.hotspot-card strong { font-size: 11px; }
.hotspot-card span { color: var(--muted); font-size: 10px; }
.explode-play {
  border: 1px solid var(--line); background: var(--panel-2); color: var(--ink);
  border-radius: 8px; width: 30px; height: 30px; font-size: 11px; cursor: pointer;
  flex: 0 0 auto;
}
.explode-play:hover { border-color: var(--accent); color: var(--accent); }

.explode-control { display: flex; align-items: center; gap: 10px; color: var(--muted); font-weight: 800; font-size: 10px; letter-spacing: .08em; }
.explode-control input { width: min(34vw, 330px); accent-color: var(--accent); }
.explode-control output { min-width: 34px; text-align: right; color: var(--text); }
.viewer-status { color: var(--muted); font-size: 11px; display: flex; align-items: center; gap: 7px; white-space: nowrap; }
.status-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--success); box-shadow: 0 0 0 4px rgba(98,215,165,.08); }
.side-panel { min-width: 0; min-height: 0; border-left: 1px solid var(--line); background: var(--panel); display: flex; flex-direction: column; position: relative; }
.search-wrap { padding: 12px; border-bottom: 1px solid var(--line); }
.search-wrap input { width: 100%; }
.side-tabs { display: grid; grid-template-columns: 1fr 1fr; border-bottom: 1px solid var(--line); }
.tab { padding: 12px; border: 0; border-bottom: 2px solid transparent; color: var(--muted); background: transparent; cursor: pointer; font-weight: 750; }
.tab.active { color: var(--text); border-bottom-color: var(--accent); }
.tab-content { display: none; flex: 1; min-height: 0; overflow: auto; }
.tab-content.active { display: block; }
.parts-tree { padding: 8px 8px 28px; }
.group-block { margin-bottom: 6px; }
.group-heading { padding: 9px 8px 6px; color: #9fb0bf; font-size: 10px; font-weight: 850; text-transform: uppercase; letter-spacing: .11em; display: flex; justify-content: space-between; }
.group-heading button { background: none; border: 0; color: var(--muted); padding: 0; cursor: pointer; font-size: 10px; }
.part-row { width: 100%; display: grid; grid-template-columns: 30px minmax(0,1fr) auto; gap: 8px; align-items: center; border: 1px solid transparent; border-radius: 9px; padding: 9px 8px; background: transparent; cursor: pointer; text-align: left; }
.part-row:hover { background: #15202a; }
.part-row.active { background: rgba(255,178,74,.1); border-color: rgba(255,178,74,.28); }
.part-index { width: 28px; height: 28px; border: 1px solid var(--line); background: #0d141b; border-radius: 7px; display: grid; place-items: center; color: #9fb0bf; font-size: 10px; font-weight: 800; }
.part-main { min-width: 0; }
.part-name { display: block; font-size: 12px; font-weight: 720; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.part-number-small { display: block; color: var(--muted); font-size: 10px; margin-top: 2px; }
.part-state { font-size: 9px; color: var(--success); border: 1px solid rgba(98,215,165,.18); padding: 3px 6px; border-radius: 999px; white-space: nowrap; }
.empty-state { padding: 70px 34px 30px; text-align: center; color: var(--muted); }
.empty-icon { width: 52px; height: 52px; margin: 0 auto 14px; border: 1px solid var(--line); border-radius: 14px; display: grid; place-items: center; font-size: 24px; color: #6f8294; }
.empty-state h3 { margin: 0 0 8px; color: var(--text); font-size: 16px; }
.empty-state p { margin: 0; font-size: 12px; line-height: 1.55; }
.details-card { padding: 18px; }
.hidden { display: none !important; }
.details-heading { display: flex; gap: 10px; justify-content: space-between; align-items: flex-start; }
.details-heading h2 { margin: 5px 0 0; font-size: 20px; letter-spacing: -.02em; }
.status-pill { padding: 5px 8px; border-radius: 999px; font-size: 9px; font-weight: 850; text-transform: uppercase; background: rgba(98,215,165,.1); color: var(--success); border: 1px solid rgba(98,215,165,.18); white-space: nowrap; }
.part-number { margin-top: 9px; font-size: 13px; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; color: var(--accent); }
.description { color: #aebdca; font-size: 12px; line-height: 1.55; margin: 14px 0 18px; }
.data-grid { margin: 0; display: grid; gap: 0; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.data-grid > div { display: grid; grid-template-columns: 42% 58%; border-bottom: 1px solid var(--line); min-height: 43px; }
.data-grid > div:last-child { border-bottom: 0; }
.data-grid dt, .data-grid dd { margin: 0; padding: 10px; font-size: 11px; }
.data-grid dt { color: var(--muted); background: #0f171f; }
.data-grid dd { color: var(--text); overflow-wrap: anywhere; }
.detail-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; margin-top: 14px; }
.dev-panel { border-top: 1px solid var(--line); background: #090f14; padding: 12px; max-height: 210px; overflow: auto; }
.dev-title { color: var(--accent-2); font-size: 10px; font-weight: 900; letter-spacing: .13em; margin-bottom: 8px; }
.dev-row { display: grid; grid-template-columns: 92px minmax(0,1fr); gap: 8px; padding: 4px 0; font-size: 10px; }
.dev-row span { color: var(--muted); }
.dev-row code { color: #cde9ff; overflow-wrap: anywhere; }
@media (max-width: 900px) {
  body { overflow: auto; }
  .app-shell { height: auto; min-height: 100dvh; }
  .topbar { align-items: flex-start; flex-direction: column; }
  .top-actions { width: 100%; }
  .compact-field { flex: 1; }
  .field select { width: 100%; min-width: 0; }
  .workspace { grid-template-columns: 1fr; grid-template-rows: 60dvh auto; }
  .side-panel { border-left: 0; border-top: 1px solid var(--line); min-height: 520px; }
  .viewer-panel { min-height: 0; }
  .viewer-toolbar { gap: 6px; }
  .metric { min-width: 70px; }
  .tool-button { padding: 8px 9px; font-size: 11px; }
  .viewer-footer { flex-direction: column; align-items: stretch; gap: 7px; }
  .explode-control input { flex: 1; width: auto; }
  .viewer-status { white-space: normal; }
}
@media (max-width: 520px) {
  .topbar { padding: 12px; }
  .top-actions { display: grid; grid-template-columns: 1fr auto; }
  .viewer-toolbar { min-height: 48px; padding: 7px 8px; }
  .metric:nth-child(2) { display: none; }
  .viewer-help { left: 8px; top: 8px; font-size: 9px; }
  .tool-button { padding: 7px 8px; }
  .workspace { grid-template-rows: 56dvh auto; }
}

/* V2: illustrated-parts-catalogue additions */
.three-tabs { grid-template-columns: repeat(3, 1fr); }
.asset-badge { color: #cde9ff; border-color: rgba(113,200,255,.24); background: rgba(113,200,255,.07); }
.bom-wrap { padding: 10px 8px 28px; }
.bom-head {
  display: grid;
  grid-template-columns: 44px minmax(0,1fr) 40px;
  gap: 8px;
  padding: 8px 9px;
  color: var(--muted);
  font-size: 9px;
  font-weight: 850;
  letter-spacing: .1em;
  border-bottom: 1px solid var(--line);
}
.bom-row {
  width: 100%;
  display: grid;
  grid-template-columns: 44px minmax(0,1fr) 40px;
  gap: 8px;
  align-items: center;
  border: 1px solid transparent;
  border-radius: 9px;
  padding: 9px;
  background: transparent;
  color: var(--text);
  cursor: pointer;
  text-align: left;
}
.bom-row:hover { background: #15202a; }
.bom-row.active { background: rgba(255,178,74,.1); border-color: rgba(255,178,74,.28); }
.bom-item { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; color: #91a3b4; font-size: 10px; }
.bom-main { min-width: 0; }
.bom-part { display:block; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; color: var(--accent); font-size: 10px; font-weight: 800; }
.bom-name { display:block; margin-top: 2px; font-size: 12px; font-weight: 700; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.bom-qty { justify-self: center; color: #c9d4de; font-size: 11px; font-weight: 800; }
.model-loading {
  position:absolute; inset:0; z-index:6; display:grid; place-items:center; pointer-events:none;
  background:rgba(8,12,16,.16); color:#9fb0bf; font-size:11px; letter-spacing:.06em;
}

/* V3: inspection orbit, reference comparison, and aggregated fasteners */
.reference-overlay {
  position: absolute;
  z-index: 8;
  top: 10px;
  right: 10px;
  bottom: 10px;
  width: min(44%, 520px);
  min-width: 320px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  border: 1px solid #405165;
  border-radius: 12px;
  background: rgba(10,15,20,.96);
  box-shadow: 0 22px 60px rgba(0,0,0,.42);
  backdrop-filter: blur(16px);
}
.reference-head { display:flex; justify-content:space-between; gap:12px; align-items:flex-start; padding:12px 12px 10px; border-bottom:1px solid var(--line); }
.reference-head strong { display:block; margin-top:4px; font-size:13px; }
.reference-close { width:32px; height:32px; border:1px solid var(--line); border-radius:8px; background:#151f29; color:var(--text); cursor:pointer; font-size:20px; line-height:1; }
.reference-image-wrap { flex:1; min-height:0; display:grid; place-items:center; padding:12px; background:#e7ebee; }
.reference-image-wrap img { display:block; max-width:100%; max-height:100%; object-fit:contain; border-radius:5px; }
.reference-note { margin:0; padding:10px 12px; color:#a9b9c7; font-size:10px; line-height:1.45; border-top:1px solid var(--line); }
.reference-meta { display:flex; justify-content:space-between; align-items:center; gap:10px; padding:0 12px 10px; color:var(--muted); font-size:9px; }
.reference-meta a { color:var(--accent-2); text-decoration:none; }
.reference-nav { display:grid; grid-template-columns:1fr auto 1fr; align-items:center; gap:8px; padding:9px 12px 11px; border-top:1px solid var(--line); }
.reference-nav button { border:1px solid var(--line); border-radius:8px; padding:7px 9px; color:var(--text); background:#151f29; cursor:pointer; }
.reference-nav button:last-child { justify-self:end; }
.reference-nav span { color:var(--muted); font-size:10px; font-weight:800; }
.viewer-canvas-wrap.isolated-mode .viewer-help { color:#ffd08c; border-color:rgba(255,178,74,.22); background:rgba(38,24,7,.72); }
.part-row .part-qty-badge { color:var(--accent); font-size:9px; font-weight:850; margin-left:5px; }
.bom-row.active-group { background:rgba(113,200,255,.08); border-color:rgba(113,200,255,.25); }

@media (max-width: 760px) {
  .reference-overlay { left:8px; right:8px; top:8px; bottom:8px; width:auto; min-width:0; }
}

/* V4: white industrial UI + lower-gloss material presentation */
:root {
  --bg:#f5f6f7;
  --panel:#ffffff;
  --panel-2:#f4f6f7;
  --panel-3:#eef1f3;
  --line:#d8dde1;
  --text:#1d252c;
  --muted:#687782;
  --accent:#1769aa;
  --accent-2:#1769aa;
  --success:#2e7d54;
  --danger:#b44747;
  --shadow:0 12px 35px rgba(38,48,58,.12);
}
body { background:#f5f6f7; color:var(--text); }
.topbar { background:rgba(255,255,255,.96); border-bottom-color:var(--line); backdrop-filter:blur(14px); }
.badge { background:#f4f6f7; color:#5f6d77; }
.asset-badge { color:#155b91; border-color:#bdd4e6; background:#eef7fd; }
select, input[type="search"] { color:var(--text); background:#fff; border-color:#cfd6db; }
select:focus, input[type="search"]:focus { border-color:#75a8cf; box-shadow:0 0 0 3px rgba(23,105,170,.10); }
.ghost-button, .tool-button, .primary-action, .secondary-action { background:#fff; border-color:#cfd6db; color:#26323a; }
.ghost-button:hover, .tool-button:hover:not(:disabled), .secondary-action:hover { border-color:#9eb5c6; background:#f6f9fb; }
.tool-button.primary, .primary-action { background:#1769aa; color:#fff; border-color:#1769aa; }
.viewer-panel { background:#fff; }
.viewer-toolbar, .viewer-footer { background:#fbfcfc; border-color:var(--line); }
.viewer-canvas-wrap { background:radial-gradient(circle at 50% 42%, #ffffff 0%, #f8f9fa 56%, #eef1f3 100%); }
.viewer-help { color:#66757f; border-color:#d8dde1; background:rgba(255,255,255,.88); }
.viewer-canvas-wrap.isolated-mode .viewer-help { color:#155b91; border-color:#b8d1e4; background:rgba(241,248,253,.94); }
.hotspot-dot { background:#1769aa; box-shadow:0 0 0 5px rgba(23,105,170,.12); }
.hotspot-card { border-color:#c8d1d7; background:rgba(255,255,255,.96); box-shadow:var(--shadow); }
.hotspot-card strong { color:#1e2830; }
.hotspot-card span { color:#63727d; }
.side-panel { background:#fff; border-left-color:var(--line); }
.search-wrap, .side-tabs { border-color:var(--line); }
.tab { color:#71808a; }
.tab.active { color:#1f2b33; border-bottom-color:#1769aa; }
.group-heading { color:#63727c; }
.part-row:hover, .bom-row:hover { background:#f5f8fa; }
.part-row.active, .bom-row.active { background:#eef6fc; border-color:#b7d3e7; }
.part-index { border-color:#d5dce0; background:#f7f8f9; color:#63727c; }
.part-state { color:#2e7d54; border-color:#c7e0d2; background:#f3faf6; }
.empty-icon { border-color:#d7dde1; color:#7d8991; background:#fafbfb; }
.status-pill { background:#f2f8f4; color:#2e7d54; border-color:#c9dfd2; }
.part-number, .bom-part { color:#155b91; }
.description { color:#586873; }
.data-grid { border-color:#d7dde1; }
.data-grid > div { border-color:#e0e4e7; }
.data-grid dt { color:#65747e; background:#f5f7f8; }
.data-grid dd { color:#26323a; background:#fff; }
.dev-panel { border-color:#d9dfe3; background:#f7f9fa; }
.dev-title, .dev-row code { color:#155b91; }
.bom-head { border-color:#d9dfe3; }
.bom-item { color:#75828b; }
.bom-qty { color:#3a464e; }
.reference-overlay { border-color:#c8d1d7; background:rgba(255,255,255,.98); box-shadow:0 18px 55px rgba(34,45,55,.18); }
.reference-head, .reference-nav { border-color:#d8dde1; }
.reference-image-wrap { background:#f1f3f4; }
.reference-note { color:#5e6d77; border-color:#d8dde1; }
.reference-meta { color:#6b7983; }
.reference-meta a { color:#155b91; }
.reference-nav button { border-color:#cfd6db; color:#28343c; background:#fff; }
.reference-close { border-color:#cfd6db; color:#28343c; background:#fff; }
.reference-nav span { color:#6c7982; }
.viewer-status { color:#63727c; }
.status-dot { background:#3a9368; box-shadow:0 0 0 4px rgba(58,147,104,.10); }
.explode-play {
  border: 1px solid var(--line); background: var(--panel-2); color: var(--ink);
  border-radius: 8px; width: 30px; height: 30px; font-size: 11px; cursor: pointer;
  flex: 0 0 auto;
}
.explode-play:hover { border-color: var(--accent); color: var(--accent); }

.explode-control { color:#66757f; }
.explode-control output { color:#26323a; }
.metric span { color:#6d7a83; }
.metric strong { color:#26323a; }

#viewer canvas { cursor: grab; }
#viewer canvas:active { cursor: grabbing; }