:root {
  color-scheme: dark;
  --ink: #eef4f7;
  --muted: #9caeb7;
  --faint: #6f828d;
  --bg: #0b1116;
  --panel: #111a21;
  --panel-strong: #16222b;
  --line: #263743;
  --line-soft: rgba(143, 174, 188, .16);
  --accent: #56c7b5;
  --accent-strong: #92eddd;
  --accent-dark: #173b38;
  --amber: #edb86a;
  --danger: #ff8d88;
  --shadow: 0 24px 70px rgba(0, 0, 0, .28);
  --radius: 14px;
}

* { box-sizing: border-box; }

html, body { min-height: 100%; }

body {
  margin: 0;
  background:
    radial-gradient(circle at 8% 0%, rgba(61, 139, 129, .13), transparent 30rem),
    radial-gradient(circle at 92% 8%, rgba(61, 100, 139, .12), transparent 32rem),
    var(--bg);
  color: var(--ink);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.45;
}

button, input { font: inherit; }
button, a { -webkit-tap-highlight-color: transparent; }
button { color: inherit; }

a { color: inherit; }

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: fixed;
  left: 1rem;
  top: -5rem;
  z-index: 100;
  padding: .75rem 1rem;
  border-radius: 8px;
  background: var(--accent-strong);
  color: #07211e;
  font-weight: 800;
}

.skip-link:focus { top: 1rem; }

.app-shell {
  width: min(1720px, 100%);
  min-height: 100vh;
  margin: 0 auto;
  padding: 0 22px;
}

.topbar {
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  border-bottom: 1px solid var(--line-soft);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}

.brand span:last-child { display: grid; gap: 1px; }
.brand strong { font-size: .95rem; letter-spacing: .02em; }
.brand small { color: var(--muted); font-size: .75rem; }

.brand-mark {
  width: 36px;
  height: 36px;
  border: 2px solid var(--accent);
  border-top-color: var(--amber);
  border-radius: 9px;
  transform: rotate(9deg);
  box-shadow: inset 0 0 0 6px rgba(86, 199, 181, .08);
}

.top-actions { display: flex; gap: 8px; }

.icon-button,
.toolbar-button,
.text-button,
.segmented button,
.views button {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(17, 26, 33, .88);
  cursor: pointer;
  transition: border-color .16s ease, background .16s ease, color .16s ease, transform .16s ease;
}

.icon-button:hover,
.toolbar-button:hover,
.text-button:hover,
.segmented button:hover,
.views button:hover { border-color: #4e6a78; background: #1a2832; }

button:focus-visible,
a:focus-visible,
input:focus-visible {
  outline: 2px solid var(--accent-strong);
  outline-offset: 2px;
}

.icon-button {
  min-height: 38px;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 0 12px;
}

.workspace {
  display: grid;
  grid-template-columns: 258px minmax(460px, 1fr) 250px;
  gap: 18px;
  padding: 22px 0 18px;
}

.sidebar,
.info-column { display: flex; flex-direction: column; gap: 14px; min-width: 0; }

.panel {
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background: rgba(17, 26, 33, .86);
  box-shadow: 0 16px 38px rgba(0, 0, 0, .12);
  padding: 18px;
}

.eyebrow {
  color: var(--accent);
  font-size: .69rem;
  font-weight: 850;
  letter-spacing: .13em;
  text-transform: uppercase;
}

h1, h2, p { margin-top: 0; }
h1 { margin-bottom: 8px; font-size: 1.55rem; letter-spacing: -.025em; }
h2 { margin-bottom: 8px; font-size: 1.05rem; }

.project-panel > p,
.download-note,
.help-panel,
.privacy-panel,
#project-description { color: var(--muted); }

.project-panel > p { font-size: .84rem; margin-bottom: 16px; }

.project-list { display: grid; gap: 8px; }

.project-card {
  width: 100%;
  position: relative;
  display: grid;
  grid-template-columns: 48px minmax(0, 1fr);
  align-items: center;
  gap: 10px;
  padding: 8px;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: #0e171d;
  color: var(--ink);
  text-align: left;
  cursor: pointer;
}

.project-card:hover { background: #15232b; }
.project-card.active { border-color: var(--accent); background: var(--accent-dark); }

.project-card img {
  width: 48px;
  height: 42px;
  object-fit: cover;
  border-radius: 6px;
  background: #d8e0e2;
}

.project-card strong,
.project-card small { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.project-card strong { font-size: .83rem; }
.project-card small { color: var(--muted); font-size: .69rem; }

.panel-heading { display: flex; justify-content: space-between; gap: 10px; align-items: end; }
.panel-heading h2 { margin-bottom: 0; }
.text-button { padding: 5px 8px; color: var(--accent-strong); font-size: .7rem; }

.search-field { display: block; margin: 12px 0 8px; }
.search-field input {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 8px 10px;
  background: #0b1319;
  color: var(--ink);
  font-size: .78rem;
}
.search-field input::placeholder { color: #71848e; }

.parts-panel { flex: 1; min-height: 260px; }
.part-list { max-height: min(45vh, 460px); overflow: auto; scrollbar-color: #36505c transparent; }

.part-row {
  width: 100%;
  display: grid;
  grid-template-columns: 18px minmax(0, 1fr);
  gap: 7px;
  align-items: center;
  padding: 7px 5px;
  border: 0;
  border-bottom: 1px solid rgba(143, 174, 188, .08);
  background: transparent;
  color: #cfdae0;
  text-align: left;
  font-size: .73rem;
  cursor: pointer;
}

.part-row:hover { color: #fff; background: rgba(255,255,255,.035); }
.part-row[aria-pressed="false"] { color: #687b85; text-decoration: line-through; }
.visibility-dot { width: 9px; height: 9px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 3px rgba(86,199,181,.1); }
.part-row[aria-pressed="false"] .visibility-dot { background: #53636c; box-shadow: none; }
.part-empty { padding: 18px 5px; color: var(--faint); font-size: .78rem; }

.viewer-column { min-width: 0; }
.viewer-header {
  min-height: 82px;
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 18px;
  padding: 0 4px 14px;
}
.viewer-header h2 { margin: 2px 0 3px; font-size: clamp(1.25rem, 2vw, 1.7rem); }
#project-description { margin: 0; max-width: 760px; font-size: .8rem; }
.project-meta { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 6px; }
.meta-chip { padding: 5px 8px; border: 1px solid var(--line); border-radius: 99px; color: var(--muted); font-size: .67rem; white-space: nowrap; }

.viewer-card {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: #0c141a;
  box-shadow: var(--shadow);
}

.toolbar,
.viewer-controls,
.statusbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 10px 12px;
  background: rgba(17, 26, 33, .97);
}

.toolbar { border-bottom: 1px solid var(--line-soft); }
.segmented { display: flex; gap: 4px; }
.segmented button,
.views button,
.toolbar-button { padding: 6px 10px; font-size: .72rem; }
.segmented button.active,
.views button.active,
.toolbar-button[aria-pressed="true"] { border-color: var(--accent); background: var(--accent-dark); color: var(--accent-strong); }

.viewer {
  position: relative;
  min-height: 620px;
  background:
    radial-gradient(circle at 50% 40%, rgba(72, 104, 118, .19), transparent 45%),
    linear-gradient(180deg, #111b22 0%, #0b1217 100%);
  overflow: hidden;
  touch-action: none;
}

#cad-canvas { width: 100%; height: 100%; display: block; position: absolute; inset: 0; }

.loading,
.viewer-error {
  position: absolute;
  inset: 0;
  display: grid;
  place-content: center;
  justify-items: center;
  gap: 8px;
  padding: 24px;
  text-align: center;
  background: rgba(11, 18, 23, .82);
  z-index: 3;
}
.loading[hidden], .viewer-error[hidden] { display: none; }
.loading small, .viewer-error p { color: var(--muted); margin: 0; max-width: 420px; }
.spinner { width: 30px; height: 30px; border: 3px solid #2d424d; border-top-color: var(--accent); border-radius: 50%; animation: spin .8s linear infinite; }
.orientation-label { position: absolute; right: 12px; bottom: 12px; color: #8299a4; font: 700 .68rem ui-monospace, monospace; pointer-events: none; }

.viewer-controls { border-top: 1px solid var(--line-soft); }
.views { display: flex; flex-wrap: wrap; gap: 4px; }
.explode-control { min-width: 260px; display: grid; grid-template-columns: auto minmax(100px, 1fr) 42px; align-items: center; gap: 9px; color: var(--muted); font-size: .72rem; }
.explode-control input { accent-color: var(--accent); }
.explode-control output { text-align: right; color: var(--ink); font-variant-numeric: tabular-nums; }

.statusbar { border-top: 1px solid var(--line-soft); color: var(--faint); font-size: .67rem; }
#status-text { color: var(--accent); }

.download-list { display: grid; gap: 8px; margin-top: 12px; }
.download-link {
  display: grid;
  grid-template-columns: minmax(0,1fr) auto;
  gap: 8px;
  align-items: center;
  padding: 11px;
  border: 1px solid var(--line);
  border-radius: 9px;
  background: #0d161c;
  text-decoration: none;
}
.download-link:hover { border-color: var(--accent); background: var(--accent-dark); }
.download-link strong, .download-link small { display: block; }
.download-link strong { font-size: .78rem; }
.download-link small { color: var(--muted); font-size: .65rem; }
.download-icon { color: var(--accent-strong); font-size: 1.15rem; }
.download-note { margin: 12px 0 0; font-size: .72rem; }

.help-panel ol { padding-left: 1.15rem; margin: 10px 0 0; font-size: .75rem; }
.help-panel li + li { margin-top: 7px; }
.privacy-panel { display: flex; align-items: flex-start; gap: 10px; }
.privacy-panel p { margin: 0; font-size: .72rem; }
.privacy-dot { flex: 0 0 auto; width: 9px; height: 9px; margin-top: 5px; border-radius: 50%; background: var(--accent); box-shadow: 0 0 0 4px rgba(86,199,181,.09); }

footer {
  min-height: 60px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border-top: 1px solid var(--line-soft);
  color: var(--faint);
  font-size: .7rem;
}
footer nav { display: flex; flex-wrap: wrap; gap: 14px; }
footer a:hover { color: var(--accent-strong); }

.toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  z-index: 20;
  transform: translate(-50%, 16px);
  padding: 9px 13px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #17242c;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transition: opacity .18s ease, transform .18s ease;
  font-size: .78rem;
}
.toast.visible { opacity: 1; transform: translate(-50%, 0); }

@keyframes spin { to { transform: rotate(360deg); } }

@media (max-width: 1180px) {
  .workspace { grid-template-columns: 230px minmax(420px, 1fr); }
  .info-column { grid-column: 1 / -1; display: grid; grid-template-columns: 1.3fr 1fr 1fr; }
  .viewer { min-height: 560px; }
}

@media (max-width: 820px) {
  .app-shell { padding: 0 12px; }
  .workspace { grid-template-columns: 1fr; }
  .sidebar { display: grid; grid-template-columns: 1fr 1fr; }
  .parts-panel { min-height: 0; }
  .part-list { max-height: 260px; }
  .viewer-header { align-items: flex-start; flex-direction: column; }
  .project-meta { justify-content: flex-start; }
  .viewer { min-height: min(64vh, 560px); }
  .viewer-controls { align-items: stretch; flex-direction: column; }
  .explode-control { min-width: 0; }
  .info-column { grid-template-columns: 1fr; }
}

@media (max-width: 560px) {
  .button-label, .mouse-help { display: none; }
  .topbar { min-height: 64px; }
  .sidebar { grid-template-columns: 1fr; }
  .project-panel > p { display: none; }
  .viewer { min-height: 52vh; }
  .toolbar { align-items: stretch; flex-direction: column; }
  .segmented { display: grid; grid-template-columns: repeat(3, 1fr); }
  .views { display: grid; grid-template-columns: repeat(3, 1fr); }
  .views button:last-child { grid-column: span 2; }
  footer { align-items: flex-start; flex-direction: column; padding: 16px 0; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { scroll-behavior: auto !important; animation-duration: .001ms !important; transition-duration: .001ms !important; }
}