html, body {
  margin: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #0f1720;
  color: #ecf3f1;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}
.viewer-shell {
  position: relative;
  width: 100vw;
  height: 100vh;
  min-height: 640px;
}
canvas {
  width: 100%;
  height: 100%;
  display: block;
  cursor: grab;
}
canvas.dragging {
  cursor: grabbing;
}
.hud {
  position: absolute;
  z-index: 3;
  display: flex;
  gap: 8px;
  align-items: center;
  border: 1px solid rgba(178, 200, 193, .24);
  background: rgba(15, 23, 32, .82);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-radius: 8px;
  padding: 9px 10px;
  box-shadow: 0 12px 32px rgba(0, 0, 0, .24);
}
.top-left { top: 12px; left: 12px; flex-direction: column; align-items: flex-start; }
.top-left strong { white-space: nowrap; }
.top-right { top: 12px; right: 12px; }
.bottom-left {
  left: 12px;
  bottom: 12px;
  max-width: calc(100vw - 24px);
  flex-wrap: wrap;
}
.hud span, .hud label {
  color: #b8c7c1;
  font-size: 12px;
}
button, select, input {
  font: inherit;
}
button, select {
  min-height: 30px;
  border: 1px solid rgba(178, 200, 193, .28);
  background: rgba(255, 255, 255, .08);
  color: #f8faf9;
  border-radius: 6px;
  padding: 0 10px;
}
button:hover {
  background: rgba(31, 118, 109, .45);
}
input[type="range"] {
  width: 180px;
}
.info {
  position: absolute;
  right: 14px;
  bottom: 14px;
  width: 310px;
  border: 1px solid rgba(178, 200, 193, .24);
  background: rgba(15, 23, 32, .92);
  border-radius: 8px;
  padding: 12px;
  line-height: 1.55;
  box-shadow: 0 14px 40px rgba(0, 0, 0, .32);
  z-index: 4;
}
.info strong {
  display: block;
  color: #ffffff;
  margin-bottom: 6px;
}
.hidden {
  display: none;
}