:root {
  --bg: #14161a;
  --bg-alt: #1c1f25;
  --border: #2c313a;
  --text: #e8eaed;
  --text-dim: #9aa2ad;
  --accent: #4f8cff;
  --accent-hover: #6ea0ff;
  --error: #ff6b6b;
}

* {
  box-sizing: border-box;
}

html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
}

#toolbar {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
  padding: 10px 16px;
  background: var(--bg-alt);
  border-bottom: 1px solid var(--border);
  z-index: 10;
}

.toolbar-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.toolbar-status {
  margin-left: auto;
  color: var(--text-dim);
  font-size: 0.85rem;
}

select, button {
  font: inherit;
  color: var(--text);
  background: #262a32;
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 7px 12px;
  cursor: pointer;
}

select:hover, button:hover {
  border-color: var(--accent);
}

button:active {
  background: #2f343d;
}

button#reset-btn {
  color: var(--text-dim);
}

#viewer-container {
  position: relative;
  flex: 1;
  min-height: 0;
}

#viewer-canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.dropzone {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
  text-align: center;
}

.dropzone-content {
  max-width: 420px;
  padding: 24px;
  color: var(--text-dim);
}

.dropzone-title {
  font-size: 1.4rem;
  font-weight: 600;
  color: var(--text);
  margin: 0 0 8px;
}

.hidden {
  display: none !important;
}

button[aria-expanded="true"],
button[aria-pressed="true"] {
  border-color: var(--accent);
  color: var(--accent-hover);
}

#viewer-canvas.picking {
  cursor: crosshair;
}

.explode-pick-panel {
  padding: 10px;
  margin-bottom: 12px;
  background: #14161a;
  border: 1px solid var(--border);
  border-radius: 8px;
}

.explode-pick-panel .setting-note {
  margin-bottom: 8px;
}

.explode-pick-panel .setting {
  margin-bottom: 8px;
}

#explode-gizmo-toggle,
#explode-pick-reset,
#explode-clear-btn {
  width: 100%;
}

#explode-gizmo-toggle {
  margin-bottom: 6px;
}

#explode-clear-btn {
  margin-bottom: 12px;
}

.settings-panel {
  position: absolute;
  top: 12px;
  right: 12px;
  width: 260px;
  max-width: calc(100% - 24px);
  max-height: calc(100% - 24px);
  overflow-y: auto;
  padding: 14px 16px;
  background: rgba(28, 31, 37, 0.94);
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 0.85rem;
  z-index: 5;
}

.settings-panel h2 {
  margin: 4px 0 10px;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.settings-panel h2:not(:first-child) {
  margin-top: 18px;
}

.setting {
  display: flex;
  flex-direction: column;
  gap: 4px;
  margin-bottom: 10px;
}

.setting > span {
  display: flex;
  justify-content: space-between;
}

.setting output {
  color: var(--text-dim);
  font-variant-numeric: tabular-nums;
}

.setting input[type="range"] {
  width: 100%;
  accent-color: var(--accent);
}

.setting-radio-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
  margin-bottom: 10px;
}

.setting-radio {
  display: flex;
  align-items: center;
  gap: 8px;
  cursor: pointer;
}

.setting-radio input[type="radio"] {
  accent-color: var(--accent);
}

.setting-inline {
  flex-direction: row;
  align-items: center;
  gap: 8px;
}

.setting-inline input[type="checkbox"] {
  accent-color: var(--accent);
}

.setting-inline input[type="color"] {
  width: 32px;
  height: 22px;
  padding: 0;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: none;
  cursor: pointer;
}

.setting-note {
  margin: 0 0 12px;
  color: var(--text-dim);
  font-size: 0.8rem;
  line-height: 1.4;
}

#settings-reset {
  width: 100%;
  margin-top: 4px;
}

.loading {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  background: rgba(20, 22, 26, 0.75);
  color: var(--text-dim);
}

.spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

.error-box {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  max-width: 90%;
  background: #3a1f1f;
  border: 1px solid var(--error);
  color: #ffd4d4;
  padding: 10px 16px;
  border-radius: 8px;
  font-size: 0.9rem;
}

.part-tooltip {
  position: absolute;
  transform: translate(-50%, -100%) translateY(-10px);
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 8px;
  background: rgba(28, 31, 37, 0.97);
  border: 1px solid var(--accent);
  border-radius: 8px;
  font-size: 0.82rem;
  white-space: nowrap;
  z-index: 8;
  pointer-events: auto;
}

.part-tooltip::after {
  content: "";
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  border: 6px solid transparent;
  border-top-color: var(--accent);
}

#part-tooltip-select {
  padding: 5px 10px;
  font-size: 0.8rem;
}