html, body {
  margin: 0;
  overflow: hidden;
}

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffffff;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.ni-wrap {
  position: relative;
  margin: 0;
  display: inline-block;
}

.ni-base,
.ni-negative {
  display: block;
  font: 800 clamp(20px, 6vw, 30px)/1.2 "Space Mono", "Courier New", monospace;
  letter-spacing: 0.02em;
}

.ni-base {
  color: #2f6df6;
}

.ni-negative {
  position: absolute;
  inset: 0;
  color: #ffffff;
  background: #2f6df6;
  padding: 4px 8px;
  margin: -4px -8px;
  border-radius: 4px;
}

@keyframes ni-flash {
  0%, 4% {
    opacity: 1;
  }
  9% {
    opacity: 0;
  }
  14% {
    opacity: 1;
  }
  19% {
    opacity: 0;
  }
  24% {
    opacity: 1;
  }
  32%, 100% {
    opacity: 0;
  }
}
.ni-wrap.is-demo .ni-negative {
  animation: ni-flash 2s ease-out infinite;
}

@media (prefers-reduced-motion: reduce) {
  .ni-negative,
  .ni-wrap.is-demo .ni-negative {
    animation: none !important;
    opacity: 0 !important;
  }
}