#chat-scroll {
  position: absolute;
  z-index: 1;
  inset-block-end: calc(100% + 9px);
  inset-inline-start: 50%;
  width: 44px;
  height: 44px;
  opacity: 0;
  visibility: hidden;
  transform: translate(-50%, 5px) scale(.94);
  pointer-events: none;
}

#chat-scroll[data-visible] {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%);
}

.chat-scroll-button {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: transparent;
  color: var(--focus);
  pointer-events: auto;
}

.chat-scroll-button::before {
  content: "";
  position: absolute;
  inset: 2px;
  border: 1px solid var(--glass-border);
  border-radius: inherit;
  background: var(--glass-fill), color-mix(in srgb, var(--surface) 60%, transparent);
  box-shadow: var(--glass-shadow);
  -webkit-backdrop-filter: blur(7px);
  backdrop-filter: blur(7px);
}

.chat-scroll-button:hover::before {
  background: var(--glass-hover), color-mix(in srgb, var(--surface) 60%, transparent);
}

.chat-scroll-button[aria-disabled="true"] {
  cursor: default;
  pointer-events: none;
}

.chat-scroll-glyphs {
  position: relative;
  width: 30px;
  height: 26px;
  overflow: hidden;
}

.chat-scroll-glyph {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  transform: translateX(0);
}

.chat-scroll-glyph svg, .chat-scroll-dots {
  grid-area: 1 / 1;
  width: 18px;
  height: 18px;
}

.chat-scroll-glyph svg {
  fill: none;
  stroke: currentColor;
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.chat-scroll-return {
  opacity: 0;
  transform: translateX(18px);
}

#chat-scroll[data-undo] .chat-scroll-latest {
  opacity: 0;
  transform: translateX(-18px);
}

#chat-scroll[data-undo] .chat-scroll-return {
  opacity: 1;
  transform: translateX(0);
}

.chat-scroll-dots {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 3px;
}

.chat-scroll-dots i {
  width: 3px;
  height: 3px;
  border-radius: 50%;
  background: currentColor;
}

#chat-scroll[data-thinking] .chat-scroll-arrow { display: none; }
#chat-scroll[data-thinking] .chat-scroll-dots { display: flex; }

@media (prefers-reduced-motion: no-preference) {
  #chat-scroll {
    transition:
      opacity 170ms ease,
      transform 210ms cubic-bezier(.22, .61, .36, 1),
      visibility 0s linear 210ms;
  }

  #chat-scroll[data-visible] { transition-delay: 0s; }

  .chat-scroll-glyph {
    transition:
      transform var(--chat-scroll-swap-duration) ease-in-out,
      opacity var(--chat-scroll-swap-duration) ease-in-out;
  }

  #chat-scroll[data-thinking][data-visible]:not([data-undo]) .chat-scroll-dots i {
    animation: chat-scroll-dot 1s ease-in-out var(--dot-delay, 0ms) infinite;
  }
  .chat-scroll-dots i:nth-child(2) { --dot-delay: 120ms; }
  .chat-scroll-dots i:nth-child(3) { --dot-delay: 240ms; }
}

@keyframes chat-scroll-dot {
  0%, 55%, 100% { transform: translateY(0); opacity: .65; }
  26% { transform: translateY(-3px); opacity: 1; }
}