html, body {
  height: 100%;
  margin: 0;
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
}

.topbar {
  display: flex;
  gap: 14px;
  align-items: center;
  padding: 10px 14px;
  border-bottom: 1px solid rgba(0,0,0,0.08);
}

.brand {
  font-weight: 700;
  letter-spacing: 0.2px;
}

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

.control select {
  padding: 6px 8px;
  border-radius: 10px;
  border: 1px solid rgba(0,0,0,0.18);
}

.hint {
  margin-left: auto;
  opacity: 0.75;
  font-size: 14px;
}

.main {
  height: calc(100% - 52px);
}

.viewer {
  width: 100%;
  height: 100%;
}

.crosshair {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 40px;
  height: 40px;
  pointer-events: none;
  z-index: 100;
}

.crosshair.hidden {
  display: none;
}

.room-info {
  position: fixed;
  top: 70px;
  right: 16px;
  width: 240px;
  background: rgba(0, 0, 0, 0.45);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  color: #fff;
  border-radius: 12px;
  padding: 14px 16px;
  z-index: 200;
  pointer-events: none;
}

.room-info.hidden {
  display: none;
}

.room-info-title {
  font-weight: 700;
  font-size: 15px;
  margin-bottom: 6px;
}

.room-info-desc {
  font-size: 13px;
  line-height: 1.5;
  opacity: 0.9;
}


.crosshair::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 0;
  width: 100%;
  height: 2px;
  background: rgba(255, 0, 0, 0.6);
  transform: translateY(-50%);
}

.crosshair::after {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  width: 2px;
  height: 100%;
  background: rgba(255, 0, 0, 0.6);
  transform: translateX(-50%);
}