*,
*::before,
*::after {
  box-sizing: border-box;
  font-family: Arial, Helvetica, sans-serif;
}

:root {
  --hue: 200;
  --saturation: 50%;
  --foreground-color: hsl(var(--hue), var(--saturation), 80%);
  --background-color: hsl(var(--hue), var(--saturation), 20%);
}

body {
  margin: 0;
  background: var(--background-color);
  overflow: hidden;
}

.scores {
  display: flex;
  justify-content: center;
  margin: 1rem 0;
}

.score {
  color: var(--foreground-color);
  padding: 0 1rem;
  font-size: 2rem;
  opacity: 0.5;
  flex: 1;
}

.score.player {
  color: var(--foreground-color);
  border-right: 0.2rem solid var(--foreground-color);
  text-align: right;
}

.paddle {
  --position: 50;

  position: absolute;
  aspect-ratio: 1/10;
  width: 1vh;
  background: var(--foreground-color);
  top: calc(var(--position) * 1vh);
  translate: 0 -50%;
}

.paddle.player {
  left: 1rem;
}
.paddle.computer {
  right: 1rem;
}

.ball {
  --x: 50;
  --y: 50;

  position: absolute;
  aspect-ratio: 1;
  width: 2vh;
  border-radius: 50%;
  background: var(--foreground-color);
  left: calc(var(--x) * 1vw);
  top: calc(var(--y) * 1vh);
  translate: -50% -50%;
}