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

.stage {
  box-sizing: border-box;
  min-height: 100vh;
  display: grid;
  place-items: center;
  margin: 0;
  background: #ff4d1f;
  font-family: -apple-system, "Segoe UI", "Noto Sans KR", sans-serif;
  padding: clamp(8px, 4vw, 24px);
}

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

.page-mock {
  position: absolute;
  inset: 24px 40px auto 24px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.page-mock__line {
  display: block;
  height: 8px;
  border-radius: 4px;
  background: rgba(255, 255, 255, 0.18);
}

.page-mock__line:nth-child(1) {
  width: 70%;
}

.page-mock__line:nth-child(2) {
  width: 50%;
}

.footer-mock {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 64px;
  background: #17141a;
  transform: translateY(100%);
}

.stage.is-demo .footer-mock {
  animation: footer-rise 2s ease-out infinite;
}

@keyframes footer-rise {
  0%, 15% {
    transform: translateY(100%);
  }
  55%, 100% {
    transform: translateY(0);
  }
}
.totop {
  position: absolute;
  right: 24px;
  bottom: 24px;
  width: 48px;
  height: 48px;
  border: 0;
  border-radius: 999px;
  background: #ffffff;
  display: grid;
  place-items: center;
  box-shadow: 0 14px 24px rgba(23, 20, 26, 0.32);
  cursor: pointer;
  transform: translateY(calc(-1 * var(--lift, 0px)));
  transition: transform 220ms ease-out;
}

.stage.is-demo .totop {
  animation: totop-lift 2s ease-out infinite;
}

@keyframes totop-lift {
  0%, 15% {
    transform: translateY(0);
  }
  55%, 100% {
    transform: translateY(-72px);
  }
}
.totop__arrow {
  width: 22px;
  height: 22px;
  fill: none;
  stroke: #17141a;
  stroke-width: 2.4;
  stroke-linecap: round;
  stroke-linejoin: round;
}

@media (prefers-reduced-motion: reduce) {
  .footer-mock, .totop, .stage.is-demo .footer-mock, .stage.is-demo .totop {
    animation: none;
    transition: none;
  }
}