:root {
  --color-bg: #000000;
  --color-fg: #6BFF6B;
}

html, body {
  background: var(--color-bg);
  color: var(--color-fg);
  font-family: "Courier New", Courier, monospace;
  text-shadow: 0 0 4px rgba(107, 255, 107, 0.5);
  height: 100%;
  margin: 0;
  padding: 0;
}

body {
  display: flex;
  align-items: center;
  justify-content: center;
}

.prompt {
  font-size: 40px;
  margin: 0;
}

.blinking {
  display: inline-block;
  width: 0.6em;
  height: 1em;
  background: var(--color-fg);
  vertical-align: -0.1em;
  animation: opacity 1s ease-in-out infinite;
}

@keyframes opacity {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}