body {
  margin: 0;
  overflow: hidden;
  background: #000;
}

canvas {
  display: block;
}

.label {
  position: absolute;
  background: rgba(255, 255, 255, 0.9);
  color: #000;
  padding: 3px 5px;
  border-radius: 4px;
  font-family: Roboto, 'Helvetica Neue', Arial;
  font-size: 0.6rem;
  transform: translate(-50%, -50%);
  pointer-events: none;
  transition: opacity 0.18s, transform 0.18s;
  will-change: transform, opacity;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.25);
}

svg {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

line {
  stroke: white;
  stroke-width: 1.5;
  opacity: 0.8;
}

#fullscreen-btn {
    position: fixed;
    top: 10px;
    right: 10px;
    z-index: 10;
    background: rgba(255, 255, 255, 0.15);
    border: none;
    color: white;
    font-size: 22px;
    border-radius: 8px;
    padding: 6px 10px;
    cursor: pointer;
    backdrop-filter: blur(5px);
    transition: background 0.3s ease, transform 0.3s ease;
}

#fullscreen-btn:hover {
    background: rgba(255, 255, 255, 0.35);
    transform: scale(1.1);
}

#container.rotate {
    transform: rotate(90deg) scale(1);
    transform-origin: center center;
    transition: transform 0.4s ease-in-out;
}