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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ffd23f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

.ug {
  position: relative;
  width: min(240px, 82vw);
  padding-bottom: 12px;
}

.ug__label {
  display: block;
  margin-bottom: 8px;
  font-weight: 700;
  font-size: 13px;
  line-height: 1;
  font-family: inherit;
  color: rgba(23, 20, 26, 0.7);
}

.ug__input {
  box-sizing: border-box;
  width: 100%;
  border: 0;
  border-bottom: 2px solid rgba(23, 20, 26, 0.3);
  padding: 8px 4px;
  font-weight: 500;
  font-size: clamp(14px, 4vw, 16px);
  line-height: 1;
  font-family: inherit;
  color: #17141a;
  background: transparent;
}
.ug__input:focus {
  outline: none;
}

.ug__underline {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: #17141a;
  transform: scaleX(0);
  transform-origin: center;
  transition: transform 300ms cubic-bezier(0.2, 1.5, 0.35, 1);
}

.ug:focus-within .ug__underline {
  transform: scaleX(1);
}

.ug__bloom {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -10px;
  height: 30px;
  background: radial-gradient(ellipse 60% 100% at 50% 0%, rgba(23, 20, 26, 0.25) 0%, rgba(23, 20, 26, 0) 72%);
  opacity: 0;
  pointer-events: none;
}

.ug:focus-within .ug__bloom {
  animation: ug-bloom 300ms ease-out;
}

@keyframes ug-bloom {
  0% {
    opacity: 0;
    transform: scaleX(0.4);
  }
  40% {
    opacity: 1;
    transform: scaleX(1);
  }
  100% {
    opacity: 0;
    transform: scaleX(1.15);
  }
}
@media (prefers-reduced-motion: reduce) {
  .ug__underline {
    transition: none;
  }
  .ug:focus-within .ug__bloom {
    animation: none;
  }
}