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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #17141a;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.nav {
  display: inline-block;
  padding: 8px 16px;
  border-radius: 8px;
  color: #fff7e6;
  text-decoration: none;
  font-weight: 700;
  font-size: clamp(16px, 4.6vw, 22px);
  line-height: 1;
  font-family: inherit;
  background: linear-gradient(90deg, #2f6df6, #2f6df6);
  background-repeat: no-repeat;
  background-position: left center;
  background-size: 0% 100%;
  animation: fill-thickness 2s ease-out infinite;
}

@keyframes fill {
  0% {
    background-size: 0% 100%;
  }
  25% {
    background-size: 100% 100%;
  }
  75% {
    background-size: 100% 100%;
  }
  100% {
    background-size: 0% 100%;
  }
}
@keyframes fill-thickness {
  0% {
    background-size: 0% 100%;
  }
  6% {
    background-size: 22% 92%;
  }
  12% {
    background-size: 44% 96%;
  }
  18% {
    background-size: 68% 88%;
  }
  25% {
    background-size: 100% 104%;
  }
  32% {
    background-size: 100% 96%;
  }
  45% {
    background-size: 100% 101%;
  }
  60% {
    background-size: 100% 94%;
  }
  75% {
    background-size: 100% 102%;
  }
  82% {
    background-size: 74% 97%;
  }
  90% {
    background-size: 38% 93%;
  }
  100% {
    background-size: 0% 100%;
  }
}
@media (prefers-reduced-motion: reduce) {
  .nav {
    animation: none;
    background-size: 100% 100%;
  }
}