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);
}

.bd-wrap {
  position: relative;
  display: inline-block;
  width: 28px;
  height: 40px;
}

.bd-chevron {
  position: absolute;
  top: 8px;
  left: 0;
  display: block;
  width: 28px;
  height: 28px;
  border-bottom: 4px solid #fff7e6;
  border-right: 4px solid #fff7e6;
  transform: rotate(45deg) translateY(0);
}

@keyframes bd-bounce {
  0%, 100% {
    transform: rotate(45deg) translateY(0);
  }
  42% {
    transform: rotate(45deg) translateY(15px);
  }
  50% {
    transform: rotate(45deg) translateY(12px);
  }
}
.bd-chevron {
  animation: bd-bounce 1.4s cubic-bezier(0.2, 1.4, 0.4, 1) infinite;
}

.bd-trail {
  position: absolute;
  top: 4px;
  left: 7px;
  display: block;
  width: 14px;
  height: 14px;
  border-bottom: 3px solid #fff7e6;
  border-right: 3px solid #fff7e6;
  opacity: 0;
}

@keyframes bd-trail {
  0%, 100% {
    opacity: 0;
    transform: rotate(45deg) translateY(-4px) scale(0.6);
  }
  50% {
    opacity: 0.3;
    transform: rotate(45deg) translateY(6px) scale(0.8);
  }
}
.bd-trail {
  animation: bd-trail 1.4s cubic-bezier(0.2, 1.4, 0.4, 1) 90ms infinite;
}

@media (prefers-reduced-motion: reduce) {
  .bd-chevron {
    animation: none !important;
    transform: rotate(45deg) translateY(0) !important;
  }
  .bd-trail {
    animation: none !important;
    opacity: 0 !important;
  }
}