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);
}

.stage {
  position: relative;
  overflow: hidden;
}

.burger {
  position: absolute;
  top: clamp(14px, 5vmin, 20px);
  left: clamp(14px, 5vmin, 20px);
  z-index: 3;
  width: clamp(34px, 10vmin, 42px);
  height: clamp(34px, 10vmin, 42px);
  border: 0;
  border-radius: 12px;
  background: transparent;
  padding: 0;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
}

.bar {
  position: absolute;
  left: 50%;
  top: 50%;
  width: clamp(20px, 6.4vmin, 26px);
  height: 3px;
  border-radius: 2px;
  background: #fff7e6;
  transition: transform 220ms cubic-bezier(0.2, 0.8, 0.2, 1), opacity 220ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.bar1 {
  transform: translate(-50%, -50%) translateY(-7px) rotate(0deg);
}

.bar2 {
  transform: translate(-50%, -50%) scaleX(1);
  opacity: 1;
}

.bar3 {
  transform: translate(-50%, -50%) translateY(7px) rotate(0deg);
}

.panel {
  position: absolute;
  inset: 0;
  z-index: 2;
  display: grid;
  place-items: center;
  gap: clamp(10px, 3.4vmin, 16px);
  background: #ff4d1f;
  transform: translateY(100%);
  transition: transform 600ms cubic-bezier(0.2, 0.8, 0.2, 1);
}

.panel__title {
  font-weight: 600;
  font-size: clamp(11px, 3.4vmin, 13px);
  line-height: 1;
  font-family: inherit;
  color: rgba(255, 247, 230, 0.7);
  letter-spacing: 0.06em;
}

.panel__links {
  display: grid;
  gap: clamp(8px, 3vmin, 14px);
  text-align: center;
}

.panel__link {
  font-weight: 700;
  font-size: clamp(15px, 5.2vmin, 20px);
  line-height: 1;
  font-family: inherit;
  color: #fff7e6;
  text-decoration: none;
}

.stage.is-open .bar1 {
  transform: translate(-50%, -50%) translateY(0) rotate(45deg);
}

.stage.is-open .bar2 {
  transform: translate(-50%, -50%) scaleX(0);
  opacity: 0;
}

.stage.is-open .bar3 {
  transform: translate(-50%, -50%) translateY(0) rotate(-45deg);
}

.stage.is-open .panel {
  transform: translateY(0);
}

.stage.is-demo .bar1 {
  animation: bar1-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.stage.is-demo .bar2 {
  animation: bar2-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.stage.is-demo .bar3 {
  animation: bar3-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

.stage.is-demo .panel {
  animation: panel-loop 2s cubic-bezier(0.2, 0.8, 0.2, 1) infinite;
}

@keyframes bar1-loop {
  0% {
    transform: translate(-50%, -50%) translateY(-7px) rotate(0deg);
  }
  15% {
    transform: translate(-50%, -50%) translateY(0) rotate(45deg);
  }
  70% {
    transform: translate(-50%, -50%) translateY(0) rotate(45deg);
  }
  85% {
    transform: translate(-50%, -50%) translateY(-7px) rotate(0deg);
  }
  100% {
    transform: translate(-50%, -50%) translateY(-7px) rotate(0deg);
  }
}
@keyframes bar2-loop {
  0% {
    transform: translate(-50%, -50%) scaleX(1);
    opacity: 1;
  }
  15% {
    transform: translate(-50%, -50%) scaleX(0);
    opacity: 0;
  }
  70% {
    transform: translate(-50%, -50%) scaleX(0);
    opacity: 0;
  }
  85% {
    transform: translate(-50%, -50%) scaleX(1);
    opacity: 1;
  }
  100% {
    transform: translate(-50%, -50%) scaleX(1);
    opacity: 1;
  }
}
@keyframes bar3-loop {
  0% {
    transform: translate(-50%, -50%) translateY(7px) rotate(0deg);
  }
  15% {
    transform: translate(-50%, -50%) translateY(0) rotate(-45deg);
  }
  70% {
    transform: translate(-50%, -50%) translateY(0) rotate(-45deg);
  }
  85% {
    transform: translate(-50%, -50%) translateY(7px) rotate(0deg);
  }
  100% {
    transform: translate(-50%, -50%) translateY(7px) rotate(0deg);
  }
}
@keyframes panel-loop {
  0% {
    transform: translateY(100%);
  }
  25% {
    transform: translateY(0);
  }
  70% {
    transform: translateY(0);
  }
  85% {
    transform: translateY(100%);
  }
  100% {
    transform: translateY(100%);
  }
}
@media (prefers-reduced-motion: reduce) {
  .stage.is-demo .bar1, .stage.is-demo .bar2, .stage.is-demo .bar3, .stage.is-demo .panel {
    animation: none;
  }
  .bar, .panel {
    transition-duration: 1ms;
  }
}