/* ============================
   Scroll to top
============================ */

.scroll-top {
  position: fixed;
  right: 1.5rem;
  bottom: 1.5rem;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  display: grid;
  place-items: center;

  color: var(--text);
  cursor: pointer;
  z-index: 999;

  background: linear-gradient(
    180deg,
    var(--accent-soft),
    var(--panel)
  );

  border: 2px solid var(--accent-border);
  box-shadow: var(--shadow-sm);

  opacity: 0;
  pointer-events: none;
  transform: translateY(10px) scale(0.96);

  transition:
    opacity var(--hover-duration) var(--hover-ease),
    transform var(--hover-duration) var(--hover-ease);
}

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

.scroll-top:hover {
  box-shadow:
    var(--shadow-lg),
    inset 0 0 0 1px var(--accent-border),
    0 0 18px var(--accent-glow);
}

.scroll-top svg {
  position: absolute;
}

.scroll-top-icon {
  z-index: 1;
}

/* Progress ring */

.progress-ring__track {
  fill: none;
  stroke: color-mix(
    in srgb,
    var(--text) 18%,
    transparent
  );
  stroke-width: 3;
}

.progress-ring__progress {
  fill: none;
  stroke: url(#scrollGradient);
  stroke-width: 3;
  stroke-linecap: round;

  transform: rotate(-90deg);
  transform-origin: 50% 50%;

  stroke-dasharray: 113;
  stroke-dashoffset: 113;

  transition: stroke-dashoffset 0.35s ease-out;
}

/* Motion preferences */
@media (prefers-reduced-motion: no-preference) {
  .scroll-top {
    transition:
      opacity var(--hover-duration) var(--hover-ease),
      transform var(--hover-duration) var(--hover-ease),
      box-shadow var(--hover-duration) var(--hover-ease);
  }
}