:root {
  color-scheme: light dark;
}

body {
  margin: 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: #222;
  font-family: system-ui, sans-serif;
}

main {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
}

#board {
  width: min(90vw, 90vh, 640px);
  height: min(90vw, 90vh, 640px);
  background: #ddd;
  border-radius: 8px;
  touch-action: manipulation;
}

.knopf {
  stroke: rgba(0, 0, 0, 0.35);
  stroke-width: 0.03;
}

.arrow {
  pointer-events: none; /* decorative only - clicks go through to the hit-region beneath */
  transform-box: fill-box;
  transform-origin: center;
}

.arrow-arc {
  fill: none;
  stroke: rgba(255, 255, 255, 0.55);
  stroke-width: 0.05;
  stroke-linecap: round;
}

.arrow-head {
  fill: rgba(255, 255, 255, 0.55);
}

.credit {
  color: #999;
  font-size: 0.8rem;
  margin: 0;
  text-align: center;
}