:root {
  --brand-bg: #0A0A0A;
  --brand-bg-elevated: #141414;
  --brand-text: #FFFFFF;
  --brand-text-dim: rgba(255, 255, 255, 0.62);
  --brand-text-faint: rgba(255, 255, 255, 0.38);
  --brand-accent: #C8A84B;
  --brand-accent-soft: rgba(200, 168, 75, 0.18);
  --brand-divider: rgba(255, 255, 255, 0.08);
  --brand-row-hover: rgba(255, 255, 255, 0.04);
  --gradient-top: #D5E6EC;
  --gradient-bottom: #C7CEC7;

  --panel-width-desktop: 320px;
  --panel-handle-height-mobile: 56px;
  --panel-half-height-mobile: 56vh;
  --panel-full-height-mobile: 88vh;

  --easing: cubic-bezier(0.32, 0.72, 0, 1);
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  width: 100%;
  overflow: hidden;
  overscroll-behavior: none;
  -webkit-user-select: none;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  font-family: "Nunito", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  color: #1a1a1a;
}

body {
  background: linear-gradient(to bottom, var(--gradient-top) 0%, var(--gradient-bottom) 100%);
  background-attachment: fixed;
}

.is-hidden {
  display: none !important;
}

/* -------- 3D canvas -------- */
#viewer-canvas {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
  touch-action: none;
}

/* -------- Loading overlay (rebranded) -------- */
#loading-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 18px;
  background: var(--brand-bg);
  z-index: 50;
  transition: opacity 320ms ease;
}
#loading-overlay.hidden {
  opacity: 0;
  pointer-events: none;
}
.loading-logo {
  width: 132px;
  height: auto;
  opacity: 0.95;
  margin-bottom: 8px;
}
.spinner {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 2.5px solid rgba(255, 255, 255, 0.14);
  border-top-color: var(--brand-accent);
  animation: spin 0.9s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }
.loading-text { text-align: center; line-height: 1.4; }
.loading-label {
  font-size: 13px;
  color: var(--brand-text-dim);
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.loading-pct {
  font-size: 22px;
  font-weight: 600;
  color: var(--brand-text);
  margin-top: 4px;
  font-variant-numeric: tabular-nums;
}

/* -------- Error overlay (rebranded) -------- */
#error-overlay {
  position: fixed;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: rgba(10, 10, 10, 0.92);
  z-index: 60;
}
.error-box {
  max-width: 360px;
  padding: 24px;
  border-radius: 12px;
  background: var(--brand-bg-elevated);
  border: 1px solid var(--brand-divider);
  text-align: center;
  color: var(--brand-text);
}
.error-title {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 8px;
}
.error-detail {
  font-size: 13px;
  color: var(--brand-text-dim);
  line-height: 1.5;
  word-break: break-word;
}

/* -------- View toolbar (top of screen, 6 view buttons) -------- */
.view-toolbar {
  position: fixed;
  top: 12px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 25;
  display: flex;
  gap: 4px;
  padding: 4px;
  background: rgba(10, 10, 10, 0.86);
  border: 1px solid var(--brand-divider);
  border-radius: 12px;
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.32);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.view-btn {
  -webkit-appearance: none;
  appearance: none;
  background: transparent;
  border: none;
  color: var(--brand-text);
  cursor: pointer;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1px;
  padding: 6px 8px;
  border-radius: 8px;
  min-width: 48px;
  transition: background-color 140ms ease, color 140ms ease;
  font-family: "Nunito", -apple-system, BlinkMacSystemFont, sans-serif;
}
.view-btn:hover {
  background: rgba(255, 255, 255, 0.06);
}
.view-btn:active,
.view-btn.is-active {
  background: var(--brand-accent-soft);
  color: var(--brand-accent);
}
.view-btn svg {
  width: 20px;
  height: 20px;
  display: block;
}
.view-label {
  font-size: 9px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--brand-text-dim);
  line-height: 1;
  margin-top: 1px;
}
.view-btn:active .view-label,
.view-btn.is-active .view-label {
  color: var(--brand-accent);
}

@media (max-width: 480px) {
  .view-toolbar { gap: 2px; padding: 3px; top: 8px; }
  .view-btn { min-width: 40px; padding: 5px 4px; }
  .view-btn svg { width: 18px; height: 18px; }
  .view-label { font-size: 8px; }
}

/* -------- Layer panel: shared base -------- */
.layer-panel {
  position: fixed;
  background: var(--brand-bg);
  color: var(--brand-text);
  z-index: 30;
  display: flex;
  flex-direction: column;
  font-family: "Nunito", -apple-system, BlinkMacSystemFont, sans-serif;
  transition: transform 320ms var(--easing);
  will-change: transform;
}

.panel-toggle {
  -webkit-appearance: none;
  appearance: none;
  background: transparent;
  border: none;
  color: var(--brand-text);
  font: inherit;
  cursor: pointer;
  display: flex;
  align-items: center;
  padding: 0;
  margin: 0;
  width: 100%;
}

.panel-logo { display: block; }
.panel-toggle-label {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--brand-text-dim);
}
.panel-chevron {
  width: 12px;
  height: 12px;
  border-right: 2px solid var(--brand-text-dim);
  border-bottom: 2px solid var(--brand-text-dim);
  transition: transform 220ms var(--easing);
}
.panel-handle {
  display: none;
}

.panel-body {
  flex: 1 1 auto;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
}
.panel-body::-webkit-scrollbar {
  width: 6px;
}
.panel-body::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.12);
  border-radius: 3px;
}

.layer-tree {
  padding: 8px 0 24px;
}

.layer-empty {
  padding: 28px 20px;
  color: var(--brand-text-faint);
  font-size: 13px;
  text-align: center;
}

/* -------- Layer tree rows -------- */
.layer-row {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px 9px 0;
  cursor: pointer;
  transition: background-color 120ms ease;
  position: relative;
}
.layer-row:hover {
  background: var(--brand-row-hover);
}

.layer-chevron {
  flex: 0 0 22px;
  height: 22px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  color: var(--brand-text-faint);
  transition: transform 180ms var(--easing);
  cursor: pointer;
}
.layer-chevron::before {
  content: "";
  display: block;
  width: 6px;
  height: 6px;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(-45deg);
}
.layer-row.is-expanded > .layer-chevron::before {
  transform: rotate(45deg);
}
.layer-chevron.is-spacer::before {
  display: none;
}

.layer-check {
  flex: 0 0 18px;
  width: 18px;
  height: 18px;
  border-radius: 4px;
  border: 1.5px solid var(--brand-text-faint);
  background: transparent;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: all 140ms ease;
  cursor: pointer;
}
.layer-check::after {
  content: "";
  display: none;
}
.layer-row[data-state="on"] .layer-check {
  background: var(--brand-accent);
  border-color: var(--brand-accent);
}
.layer-row[data-state="on"] .layer-check::after {
  display: block;
  width: 5px;
  height: 9px;
  border-right: 2px solid var(--brand-bg);
  border-bottom: 2px solid var(--brand-bg);
  transform: translateY(-1px) rotate(45deg);
}
.layer-row[data-state="partial"] .layer-check {
  background: var(--brand-accent-soft);
  border-color: var(--brand-accent);
}
.layer-row[data-state="partial"] .layer-check::after {
  display: block;
  width: 8px;
  height: 2px;
  background: var(--brand-accent);
  border: none;
  transform: none;
}

.layer-label {
  flex: 1 1 auto;
  font-size: 14px;
  font-weight: 500;
  color: var(--brand-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.layer-row[data-state="off"] .layer-label {
  color: var(--brand-text-faint);
}

.layer-count {
  flex: 0 0 auto;
  font-size: 11px;
  font-weight: 500;
  color: var(--brand-text-faint);
  font-variant-numeric: tabular-nums;
  padding-left: 6px;
}

.layer-children {
  overflow: hidden;
  transition: max-height 240ms var(--easing);
}
.layer-row + .layer-children.is-collapsed {
  display: none;
}

/* -------- Desktop layout: left drawer -------- */
@media (min-width: 769px) {
  .layer-panel {
    top: 0;
    left: 0;
    bottom: 0;
    width: var(--panel-width-desktop);
    border-right: 1px solid var(--brand-divider);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.18);
  }
  .layer-panel.is-collapsed {
    transform: translateX(calc(-1 * var(--panel-width-desktop)));
  }
  .panel-toggle {
    position: relative;
    padding: 18px 20px 16px;
    border-bottom: 1px solid var(--brand-divider);
    gap: 12px;
    justify-content: flex-start;
  }
  .panel-logo {
    width: 110px;
    height: auto;
  }
  .panel-toggle-label {
    display: none;
  }
  .panel-chevron {
    margin-left: auto;
    transform: rotate(135deg); /* points left when open */
  }
  .layer-panel.is-collapsed .panel-chevron {
    transform: rotate(-45deg);
  }
  .layer-panel.is-collapsed .panel-toggle {
    position: fixed;
    top: 18px;
    left: 18px;
    width: auto;
    background: var(--brand-bg);
    border: 1px solid var(--brand-divider);
    border-radius: 10px;
    padding: 10px 14px;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.22);
    z-index: 31;
  }
  .layer-panel.is-collapsed .panel-toggle .panel-logo {
    width: 80px;
  }

  #panel-scrim {
    display: none !important;
  }
}

/* -------- Mobile layout: bottom sheet -------- */
@media (max-width: 768px) {
  .layer-panel {
    left: 0;
    right: 0;
    bottom: 0;
    height: var(--panel-half-height-mobile);
    max-height: var(--panel-full-height-mobile);
    border-top-left-radius: 18px;
    border-top-right-radius: 18px;
    box-shadow: 0 -8px 32px rgba(0, 0, 0, 0.32);
    transform: translateY(calc(100% - var(--panel-handle-height-mobile)));
    transition: transform 320ms var(--easing), height 320ms var(--easing);
  }
  .layer-panel.is-half {
    transform: translateY(0);
    height: var(--panel-half-height-mobile);
  }
  .layer-panel.is-full {
    transform: translateY(0);
    height: var(--panel-full-height-mobile);
  }
  .layer-panel.is-collapsed {
    transform: translateY(calc(100% - var(--panel-handle-height-mobile)));
  }
  .panel-toggle {
    height: var(--panel-handle-height-mobile);
    padding: 0 20px;
    border-bottom: 1px solid var(--brand-divider);
    gap: 12px;
    position: relative;
  }
  .panel-handle {
    display: block;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    width: 38px;
    height: 4px;
    border-radius: 2px;
    background: rgba(255, 255, 255, 0.28);
  }
  .panel-logo {
    width: 88px;
    height: auto;
    margin-top: 4px;
  }
  .panel-toggle-label {
    display: inline-block;
    margin-top: 4px;
  }
  .panel-chevron {
    margin-left: auto;
    margin-top: 4px;
    transform: rotate(-135deg); /* points up when collapsed */
  }
  .layer-panel.is-half .panel-chevron,
  .layer-panel.is-full .panel-chevron {
    transform: rotate(45deg); /* points down when expanded */
  }

  #panel-scrim {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.42);
    z-index: 29;
    opacity: 0;
    transition: opacity 240ms ease;
    pointer-events: none;
  }
  #panel-scrim.is-visible {
    opacity: 1;
    pointer-events: auto;
  }

  .layer-row { padding-top: 11px; padding-bottom: 11px; } /* bigger touch target */
}