/**
 * RunMyCampus back-to-top — premium floating control on every shell.
 * Always fixed above assist dock; never buried in dock secondary menu.
 */

:root {
  --rmc-back-to-top-size: 3.25rem;
  --rmc-back-to-top-edge-bottom: max(0.45rem, env(safe-area-inset-bottom, 0px));
  --rmc-back-to-top-edge-right: max(1.15rem, env(safe-area-inset-right, 0px));
  --rmc-back-to-top-z: 10475;
  --rmc-back-to-top-dock-lift: 0px;
}

html[data-surface="control-plane"],
html[data-surface="tenant"] body.portal-body-with-layout {
  --rmc-back-to-top-edge-right: max(1rem, env(safe-area-inset-right, 0px));
}

body[data-rmc-assist-dock="mounted"] {
  --rmc-back-to-top-dock-lift: calc(
    var(--rmc-assist-rail-height, calc(var(--rmc-assist-btn-size, 48px) * 2 + var(--rmc-assist-gap, 10px) * 2)) +
    var(--rmc-assist-gap, 10px) +
    0.35rem
  );
}

.rmc-back-to-top-gradient-stop--primary {
  stop-color: var(--school-primary, #4f46e5);
}

.rmc-back-to-top-gradient-stop--accent {
  stop-color: var(--school-accent, #10b981);
}

.back-to-top-btn.rmc-back-to-top {
  --rmc-back-to-top-progress: 0;
  --rmc-back-to-top-primary: var(--school-primary, #4f46e5);
  --rmc-back-to-top-accent: var(--school-accent, #10b981);
  position: fixed;
  bottom: calc(var(--rmc-back-to-top-edge-bottom) + var(--rmc-back-to-top-dock-lift));
  right: var(--rmc-back-to-top-edge-right);
  z-index: var(--rmc-back-to-top-z);
  min-width: var(--rmc-back-to-top-size);
  height: var(--rmc-back-to-top-size);
  padding: 0;
  margin: 0;
  border: none;
  border-radius: 999px;
  background: color-mix(
    in oklab,
    var(--surface-elevated, var(--portal-bg, var(--color-base-0))) 90%,
    transparent
  );
  color: var(--text-primary, var(--portal-text, var(--color-base-900)));
  box-shadow:
    var(--elev-2, 0 8px 24px rgba(15, 23, 42, 0.14)),
    inset 0 1px 0 color-mix(in oklab, var(--text-on-brand, #fff) 16%, transparent);
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  overflow: hidden;
  isolation: isolate;
  -webkit-backdrop-filter: blur(calc(var(--material-blur, 12px) + 2px));
          backdrop-filter: blur(calc(var(--material-blur, 12px) + 2px));
  transition:
    width var(--motion-normal, 220ms ease),
    min-width var(--motion-normal, 220ms ease),
    padding var(--motion-normal, 220ms ease),
    transform var(--motion-normal, 220ms ease),
    box-shadow var(--motion-normal, 220ms ease),
    opacity var(--motion-fast, 150ms ease),
    visibility var(--motion-fast, 150ms ease),
    bottom var(--motion-normal, 220ms ease);
  touch-action: none;
  -webkit-user-select: none;
          user-select: none;
}

.back-to-top-btn.rmc-back-to-top::before {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(
    145deg,
    color-mix(in oklab, var(--rmc-back-to-top-primary) 62%, transparent),
    color-mix(in oklab, var(--rmc-back-to-top-accent) 48%, transparent)
  );
  -webkit-mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  mask:
    linear-gradient(#fff 0 0) content-box,
    linear-gradient(#fff 0 0);
  -webkit-mask-composite: xor;
          mask-composite: exclude;
  pointer-events: none;
  opacity: 0.95;
}

.rmc-back-to-top__chip {
  position: relative;
  display: grid;
  place-items: center;
  width: var(--rmc-back-to-top-size);
  height: var(--rmc-back-to-top-size);
  flex: 0 0 auto;
}

.rmc-back-to-top__ring {
  position: absolute;
  inset: -3px;
  display: grid;
  place-items: center;
  pointer-events: none;
}

.rmc-back-to-top__svg {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.rmc-back-to-top__track {
  fill: none;
  stroke: color-mix(in oklab, var(--hairline, rgba(15, 23, 42, 0.12)) 75%, transparent);
  stroke-width: 2.5;
}

.rmc-back-to-top__progress {
  fill: none;
  stroke: url(#rmc-back-to-top-gradient);
  stroke-width: 3;
  stroke-linecap: round;
  stroke-dasharray: 1;
  stroke-dashoffset: calc(1 - var(--rmc-back-to-top-progress, 0));
  filter: drop-shadow(
    0 0 6px color-mix(in oklab, var(--rmc-back-to-top-primary) 35%, transparent)
  );
  transition: stroke-dashoffset var(--motion-fast, 150ms ease);
}

.rmc-back-to-top__icon {
  position: relative;
  z-index: 1;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.55rem;
  height: 1.55rem;
  margin-top: -0.35rem;
  border-radius: 999px;
  background: linear-gradient(
    145deg,
    color-mix(in oklab, var(--rmc-back-to-top-primary) 22%, transparent),
    color-mix(in oklab, var(--rmc-back-to-top-accent) 16%, transparent)
  );
  color: var(--rmc-back-to-top-primary);
  font-size: 1.35rem;
  line-height: 1;
  transition: transform var(--motion-normal, 220ms ease);
}

.rmc-back-to-top__percent {
  position: absolute;
  bottom: 0.42rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  font-family: var(--font-mono, ui-monospace, "JetBrains Mono", monospace);
  font-size: 0.58rem;
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1;
  color: color-mix(in oklab, var(--text-primary, #0f172a) 82%, var(--rmc-back-to-top-primary) 18%);
  font-variant-numeric: tabular-nums;
  pointer-events: none;
}

.rmc-back-to-top__percent::after {
  content: "%";
  font-size: 0.48rem;
  opacity: 0.72;
}

.rmc-back-to-top__caption {
  max-width: 0;
  opacity: 0;
  overflow: hidden;
  white-space: nowrap;
  font-size: var(--type-size-caption, 0.8125rem);
  font-weight: 650;
  letter-spacing: -0.02em;
  padding-right: 0;
  transition:
    max-width var(--motion-normal, 220ms ease),
    opacity var(--motion-fast, 150ms ease),
    padding var(--motion-normal, 220ms ease);
}

.rmc-back-to-top__label {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.back-to-top-btn.rmc-back-to-top:hover,
.back-to-top-btn.rmc-back-to-top:focus-visible {
  transform: translateY(-4px);
  box-shadow:
    var(--elev-3, 0 18px 48px rgba(15, 23, 42, 0.18)),
    0 0 0 1px color-mix(in oklab, var(--rmc-back-to-top-primary) 18%, transparent);
}

.back-to-top-btn.rmc-back-to-top:hover .rmc-back-to-top__icon,
.back-to-top-btn.rmc-back-to-top:focus-visible .rmc-back-to-top__icon {
  transform: translateY(-2px);
}

.back-to-top-btn.rmc-back-to-top:focus-visible {
  outline: 2px solid color-mix(in oklab, var(--rmc-back-to-top-primary) 72%, transparent);
  outline-offset: 3px;
}

.back-to-top-btn.rmc-back-to-top[hidden] {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transform: translateY(0.85rem) scale(0.9);
}

.back-to-top-btn.rmc-back-to-top.rmc-back-to-top--visible:not([hidden]) {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
  animation: rmc-back-to-top-enter var(--motion-spring, 420ms cubic-bezier(0.34, 1.56, 0.64, 1));
}

.back-to-top-btn.rmc-back-to-top.rmc-back-to-top--idle:not([hidden]) {
  opacity: 0.62;
  transform: translateY(0) scale(0.94);
  box-shadow: var(--elev-1, 0 4px 12px rgba(15, 23, 42, 0.1));
}

.back-to-top-btn.rmc-back-to-top.rmc-back-to-top--idle:not([hidden]):hover,
.back-to-top-btn.rmc-back-to-top.rmc-back-to-top--idle:not([hidden]):focus-visible {
  opacity: 1;
  transform: translateY(0) scale(1);
}

.back-to-top-btn.rmc-back-to-top.rmc-back-to-top--launching .rmc-back-to-top__icon {
  animation: rmc-back-to-top-launch 520ms var(--motion-decel, 260ms ease);
}

.back-to-top-btn.rmc-back-to-top:active .rmc-back-to-top__icon {
  transform: translateY(0) scale(0.92);
}

.back-to-top-btn.rmc-back-to-top.rmc-back-to-top--dragging {
  transition: none;
  cursor: grabbing;
  opacity: 1;
  transform: none;
}

@keyframes rmc-back-to-top-enter {
  from {
    opacity: 0;
    transform: translateY(1rem) scale(0.86);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes rmc-back-to-top-launch {
  0% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(-6px);
  }
  100% {
    transform: translateY(0);
  }
}

@media (hover: hover) and (min-width: 768px) {
  .back-to-top-btn.rmc-back-to-top:hover,
  .back-to-top-btn.rmc-back-to-top:focus-visible {
    padding-inline-end: 0.95rem;
  }

  .back-to-top-btn.rmc-back-to-top:hover .rmc-back-to-top__caption,
  .back-to-top-btn.rmc-back-to-top:focus-visible .rmc-back-to-top__caption {
    max-width: 8rem;
    opacity: 1;
    padding-right: 0.15rem;
  }

  .back-to-top-btn.rmc-back-to-top:hover .rmc-back-to-top__percent,
  .back-to-top-btn.rmc-back-to-top:focus-visible .rmc-back-to-top__percent {
    opacity: 0;
  }
}

/* Marketing editorial surface */
html[data-surface="marketing"] .back-to-top-btn.rmc-back-to-top {
  background: color-mix(in oklab, var(--mkt-cream, #faf7f2) 94%, transparent);
  color: var(--mkt-ink, var(--text-primary, #1c1917));
  box-shadow:
    0 12px 32px color-mix(in oklab, var(--mkt-primary, #1e3a5f) 14%, transparent),
    inset 0 1px 0 rgba(255, 255, 255, 0.65);
}

html[data-surface="marketing"] .rmc-back-to-top-gradient-stop--primary {
  stop-color: var(--mkt-primary, #1e3a5f);
}

html[data-surface="marketing"] .rmc-back-to-top-gradient-stop--accent {
  stop-color: var(--mkt-accent, #c9a227);
}

html[data-surface="marketing"] .rmc-back-to-top__icon {
  color: var(--mkt-primary, #1e3a5f);
}

/* Dark / admin contexts */
[data-theme="dark"] .back-to-top-btn.rmc-back-to-top,
.portal-backend-dark .back-to-top-btn.rmc-back-to-top {
  background: color-mix(
    in oklab,
    var(--admin-content-surface, var(--surface-elevated, #1a2234)) 92%,
    transparent
  );
  color: var(--admin-content-text, var(--text-primary, #f1f5f9));
}

[data-theme="dark"] .rmc-back-to-top__percent,
.portal-backend-dark .rmc-back-to-top__percent {
  color: color-mix(in oklab, var(--text-primary, #f8fafc) 88%, var(--rmc-back-to-top-accent) 12%);
}

/* Control plane operator footer clearance */
html[data-surface="control-plane"] body.cp-shell-has-operator-footer .back-to-top-btn.rmc-back-to-top {
  bottom: calc(4.45rem + var(--rmc-back-to-top-dock-lift) + env(safe-area-inset-bottom, 0px));
}

html[data-rmc-exceeds-2-folds="1"] .back-to-top-btn.rmc-back-to-top {
  bottom: calc(1.15rem + var(--rmc-back-to-top-dock-lift) + env(safe-area-inset-bottom, 0px));
}

/* Manager /admin/: clear copilot rail + notebook footer */
body.admin-manager-shell .back-to-top-btn.rmc-back-to-top {
  right: calc(
    var(--rmc-back-to-top-edge-right) + var(--rmc-app-shell-copilot-w, 44px) + 0.35rem
  );
  z-index: calc(var(--rmc-back-to-top-z) + 5);
}

body.admin-manager-shell .rmc-app-shell[data-copilot="expanded"] ~ .back-to-top-btn.rmc-back-to-top,
body.admin-manager-shell:has(.rmc-app-shell[data-copilot="expanded"]) .back-to-top-btn.rmc-back-to-top {
  right: calc(
    var(--rmc-back-to-top-edge-right) + var(--rmc-app-shell-copilot-w, 360px) + 0.35rem
  );
}

body.admin-manager-shell:has(.rmc-footer-notebook-anchor) .back-to-top-btn.rmc-back-to-top {
  bottom: calc(3.85rem + var(--rmc-back-to-top-dock-lift) + env(safe-area-inset-bottom, 0px));
}

html[data-surface="control-plane"][data-rmc-exceeds-2-folds="1"]
  body.cp-shell-has-operator-footer
  .back-to-top-btn.rmc-back-to-top {
  bottom: calc(4.45rem + var(--rmc-back-to-top-dock-lift) + env(safe-area-inset-bottom, 0px));
}

@media (prefers-reduced-motion: reduce) {
  .back-to-top-btn.rmc-back-to-top,
  .back-to-top-btn.rmc-back-to-top .rmc-back-to-top__icon,
  .back-to-top-btn.rmc-back-to-top .rmc-back-to-top__progress,
  .back-to-top-btn.rmc-back-to-top .rmc-back-to-top__caption {
    transition: none;
    animation: none !important;
  }

  .back-to-top-btn.rmc-back-to-top[hidden] {
    transform: none;
  }
}

@media (max-width: 767px) {
  :root {
    --rmc-back-to-top-size: 3rem;
  }

  .rmc-back-to-top__percent {
    font-size: 0.54rem;
  }
}

/* ================================================================== *
 * VARIANTS — both driven by the JS-set --rmc-back-to-top-progress.    *
 * Selected by the .rmc-back-to-top--aurora / --mercury class (JS      *
 * resolves it; ?btt=aurora|mercury flips + persists for live compare).*
 * ================================================================== */

/* mercury fill element is inert unless the mercury variant is active */
.rmc-back-to-top__fill { display: none; }

/* ---------- Concept A · Aurora (default) ---------- */
/* conic progress halo replaces the thin SVG ring; frosted glass with a slow
   rotating aurora sheen + a gentle glow breath. */
.rmc-back-to-top--aurora .rmc-back-to-top__svg { display: none; }

.rmc-back-to-top--aurora .rmc-back-to-top__ring {
  inset: -2px;
  border-radius: 999px;
  background: conic-gradient(
    from -90deg,
    var(--rmc-back-to-top-primary, #4f46e5) 0deg,
    color-mix(in oklab, var(--rmc-back-to-top-primary, #4f46e5) 55%, var(--rmc-back-to-top-accent, #10b981))
      calc(var(--rmc-back-to-top-progress, 0) * 180deg),
    var(--rmc-back-to-top-accent, #10b981) calc(var(--rmc-back-to-top-progress, 0) * 360deg),
    color-mix(in oklab, var(--hairline, rgba(120, 120, 140, 0.2)) 60%, transparent) 0deg
  );
  -webkit-mask: radial-gradient(farthest-side, transparent calc(100% - 3px), #000 calc(100% - 3px));
          mask: radial-gradient(farthest-side, transparent calc(100% - 3px), #000 calc(100% - 3px));
  filter: drop-shadow(0 0 5px color-mix(in oklab, var(--rmc-back-to-top-primary, #4f46e5) 45%, transparent));
}

/* rotating aurora sheen */
.rmc-back-to-top--aurora .rmc-back-to-top__chip::after {
  content: "";
  position: absolute;
  inset: 4px;
  border-radius: 999px;
  background: conic-gradient(
    from 0deg,
    transparent,
    color-mix(in oklab, var(--rmc-back-to-top-primary, #7c6cff) 22%, transparent),
    transparent 42%
  );
  animation: rmc-btt-aurora-spin 6s linear infinite;
  pointer-events: none;
  z-index: 0;
}

.rmc-back-to-top--aurora.rmc-back-to-top--visible:not([hidden]) {
  animation:
    rmc-back-to-top-enter var(--motion-spring, 420ms cubic-bezier(0.34, 1.56, 0.64, 1)),
    rmc-btt-aurora-glow 5.2s ease-in-out infinite;
}

@keyframes rmc-btt-aurora-spin {
  to { transform: rotate(360deg); }
}
@keyframes rmc-btt-aurora-glow {
  0%, 100% {
    box-shadow:
      var(--elev-2, 0 8px 24px rgba(15, 23, 42, 0.14)),
      0 8px 26px -10px color-mix(in oklab, var(--rmc-back-to-top-primary, #4f46e5) 42%, transparent),
      inset 0 1px 0 color-mix(in oklab, var(--text-on-brand, #fff) 16%, transparent);
  }
  50% {
    box-shadow:
      var(--elev-2, 0 8px 24px rgba(15, 23, 42, 0.14)),
      0 14px 40px -8px color-mix(in oklab, var(--rmc-back-to-top-primary, #4f46e5) 60%, transparent),
      inset 0 1px 0 color-mix(in oklab, var(--text-on-brand, #fff) 22%, transparent);
  }
}

/* ---------- Concept B · Mercury (liquid fill) ---------- */
.rmc-back-to-top--mercury .rmc-back-to-top__svg,
.rmc-back-to-top--mercury .rmc-back-to-top__ring { display: none; }

.rmc-back-to-top--mercury .rmc-back-to-top__fill {
  display: block;
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: calc(var(--rmc-back-to-top-progress, 0) * 100%);
  background: linear-gradient(
    180deg,
    color-mix(in oklab, var(--rmc-back-to-top-primary, #4f46e5) 78%, #fff),
    var(--rmc-back-to-top-primary, #4f46e5) 42%,
    var(--rmc-back-to-top-accent, #10b981)
  );
  opacity: 0.94;
  z-index: 0;
  transition: height var(--motion-fast, 150ms ease);
}
.rmc-back-to-top--mercury .rmc-back-to-top__fill::before {
  content: "";
  position: absolute;
  top: -5px;
  left: -12%;
  width: 124%;
  height: 10px;
  border-radius: 50%;
  background: color-mix(in oklab, var(--rmc-back-to-top-primary, #4f46e5) 68%, var(--rmc-back-to-top-accent, #10b981));
  opacity: 0.72;
}
.rmc-back-to-top--mercury .rmc-back-to-top__icon {
  z-index: 1;
  background: none;
  margin-top: 0;
  color: var(--text-primary, #1c1917);
  text-shadow: 0 1px 2px color-mix(in oklab, var(--text-on-brand, #fff) 55%, transparent);
}
.rmc-back-to-top--mercury .rmc-back-to-top__percent {
  z-index: 2;
  color: var(--text-on-brand, #fff);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.4);
}

@media (prefers-reduced-motion: reduce) {
  .rmc-back-to-top--aurora.rmc-back-to-top--visible:not([hidden]),
  .rmc-back-to-top--aurora .rmc-back-to-top__chip::after {
    animation: none !important;
  }
}