/* motion/uiextras.css — FAQ 过渡、滚动进度条、返回顶部。 */

.faq-list summary {
  transition: color 0.2s;
}

.faq-list summary:hover,
.faq-list details[open] summary {
  color: var(--mint);
}

.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 120;
  height: 2px;
  pointer-events: none;
  background: transparent;
}

.scroll-progress i {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--mint-strong), var(--mint));
  transform: scaleX(0);
  transform-origin: 0 50%;
}

.back-top {
  position: fixed;
  right: 22px;
  bottom: 22px;
  z-index: 90;
  width: 44px;
  height: 44px;
  padding: 0;
  display: grid;
  place-items: center;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  color: rgba(255, 255, 255, 0.7);
  background: rgba(13, 25, 22, 0.88);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.3s, transform 0.3s, color 0.2s, border-color 0.2s;
}

.back-top.back-top-in {
  opacity: 1;
  transform: translateY(0);
}

.back-top.back-top-in:hover {
  border-color: var(--mint);
  color: var(--mint);
  transform: translateY(-2px);
}

.back-top:focus-visible {
  outline: 3px solid rgba(185, 248, 211, 0.4);
  outline-offset: 3px;
}

.back-top svg {
  width: 18px;
  height: 18px;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.8;
  stroke-linecap: round;
}

@media (max-width: 760px) {
  .back-top {
    right: 14px;
    bottom: 14px;
    width: 40px;
    height: 40px;
  }
}

body.has-checkout-open .scroll-progress,
body.has-checkout-open .back-top {
  opacity: 0;
  pointer-events: none;
}

@media (prefers-reduced-motion: reduce) {
  .back-top {
    transition: none;
  }
}