/* 右下フロート — AI相談オフ時のスクロールトップ（進捗リング） */

:root {
  --float-dock-right: 2rem;
  --float-dock-bottom: 2rem;
  --float-dock-width: 3rem;
  --float-dock-height: 3rem;
  --float-dock-gap: 0.75rem;
  --scroll-top-size: 3rem;
}

@media (max-width: 767px) {
  :root {
    --float-dock-right: 1.25rem;
    --scroll-top-size: 2.75rem;
    --float-dock-width: 2.75rem;
    --float-dock-height: 2.75rem;
  }
}

@media (min-width: 768px) {
  :root {
    --float-dock-right: 2rem;
  }
}

#effort-scroll-top-root {
  position: fixed;
  right: var(--float-dock-right);
  bottom: var(--float-dock-bottom);
  z-index: 50;
  pointer-events: none;
}

.scroll-top {
  --scroll-top-progress: 0;
  position: relative;
  display: grid;
  place-items: center;
  width: var(--scroll-top-size);
  height: var(--scroll-top-size);
  padding: 0;
  border: none;
  border-radius: 999px;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  pointer-events: auto;
  opacity: 0;
  visibility: hidden;
  transform: translateY(0.5rem) scale(0.92);
  transition:
    opacity 0.4s cubic-bezier(0.16, 1, 0.3, 1),
    transform 0.4s cubic-bezier(0.16, 1, 0.3, 1),
    visibility 0.4s,
    color 0.25s ease;
}

.scroll-top.is-visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
}

.scroll-top:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 3px;
}

.scroll-top__ring {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
}

.scroll-top__ring-track {
  stroke: color-mix(in srgb, var(--ink) 14%, transparent);
  stroke-width: 1.75;
}

.scroll-top__ring-progress {
  stroke: var(--blue);
  stroke-width: 1.75;
  stroke-linecap: round;
  transition: stroke-dashoffset 0.12s linear;
}

.scroll-top__face {
  position: relative;
  z-index: 1;
  display: grid;
  place-items: center;
  width: calc(var(--scroll-top-size) - 0.7rem);
  height: calc(var(--scroll-top-size) - 0.7rem);
  border-radius: 999px;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  border: 1px solid color-mix(in srgb, var(--ink) 12%, transparent);
  box-shadow:
    0 1px 2px rgb(15 23 42 / 0.06),
    0 8px 24px rgb(15 23 42 / 0.08);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  transition:
    background 0.25s ease,
    border-color 0.25s ease,
    transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.scroll-top__face svg {
  width: 1.05rem;
  height: 1.05rem;
}

.scroll-top:hover .scroll-top__face,
.scroll-top:focus-visible .scroll-top__face {
  background: var(--paper);
  border-color: color-mix(in srgb, var(--accent) 35%, transparent);
  transform: translateY(-1px);
}

.scroll-top:hover .scroll-top__ring-progress,
.scroll-top:focus-visible .scroll-top__ring-progress {
  stroke: var(--blue-hover);
}

@media (prefers-reduced-motion: reduce) {
  .scroll-top,
  .scroll-top__face,
  .scroll-top__ring-progress {
    transition: none;
  }
}