/* =========================================================================
 * TOC Rail — right-hand table-of-contents for articles & case studies.
 * Companion to assets/js/toc-rail.js.
 *
 * Variants are scoped with .toc-rail[data-variant="..."]:
 *   luma    — hairline rail + round dot that glides between items
 *   minimal — stretching capsule indicator + bold hover pills
 *   compact — dense, numbered, with reading-progress fill on the rail
 * ====================================================================== */

:root {
  --toc-rail-accent: var(--accent-primary, var(--color-hibiscus, #be3455));
  --toc-rail-line: var(--border-primary, #e9e8ea);
  --toc-rail-text: var(--text-tertiary, rgba(25, 10, 38, 0.55));
  --toc-rail-text-hover: var(--text-primary, #190a26);
  --toc-rail-skeleton: rgba(127, 127, 127, 0.16);
  --toc-rail-skeleton-sheen: rgba(127, 127, 127, 0.28);
  --toc-rail-width: 232px;
  --toc-rail-gap: 64px; /* distance from the content column to the rail */
}

[data-theme="dark"] {
  --toc-rail-line: var(--dm-border-primary, #404040);
  --toc-rail-text: var(--dm-text-tertiary, #808080);
  --toc-rail-text-hover: var(--dm-text-primary, #f0f0f0);
  --toc-rail-skeleton: rgba(255, 255, 255, 0.08);
  --toc-rail-skeleton-sheen: rgba(255, 255, 255, 0.16);
}

/* Headings land below the fixed nav when scrolled to */
[data-toc-target] {
  scroll-margin-top: 104px;
}

/* ------------------------------------------------------------------
 * Rail shell — fixed to the right of the content column
 * ---------------------------------------------------------------- */
.toc-rail {
  position: fixed;
  top: 128px;
  left: 50%;
  transform: translateX(calc(var(--measure, 38em) / 2 + var(--toc-rail-gap)));
  width: var(--toc-rail-width);
  max-height: calc(100vh - 192px);
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: none;
  z-index: 40;
  font-family: var(--font-family-ui, sans-serif);
}

.toc-rail::-webkit-scrollbar {
  display: none;
}

@media (max-width: 1219px) {
  .toc-rail {
    display: none;
  }
}

.toc-rail__inner {
  position: relative;
  padding-left: 20px;
}

/* Vertical border line separating content and TOC */
.toc-rail__line {
  position: absolute;
  left: 0;
  top: 4px;
  bottom: 4px;
  width: 1px;
  background: var(--toc-rail-line);
}

.toc-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
}

/* Indentation per heading level */
.toc-rail__item[data-level="3"] { padding-left: 16px; }
.toc-rail__item[data-level="4"] { padding-left: 32px; }

.toc-rail__link {
  display: block;
  padding: 5px 8px 5px 0;
  color: var(--toc-rail-text);
  font-size: 0.9375rem;
  line-height: 1.4;
  font-weight: var(--font-weight-regular, 420);
  text-decoration: none;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  border-radius: 6px;
  transition: color 160ms ease, background-color 160ms ease;
}

.toc-rail__link:hover {
  color: var(--toc-rail-text-hover);
}

.toc-rail__link:focus-visible {
  outline: 2px solid var(--toc-rail-accent);
  outline-offset: 2px;
}

.toc-rail__link[aria-current] {
  color: var(--toc-rail-accent);
}

/* ------------------------------------------------------------------
 * Indicator primitives (positioned by JS via --dot-y / transform)
 * ---------------------------------------------------------------- */
.toc-rail__indicator {
  position: absolute;
  left: 50%;
  top: 0;
  background: var(--toc-rail-accent);
  opacity: 0;
}

.toc-rail.is-ready .toc-rail__indicator {
  opacity: 1;
  transition: opacity 240ms ease;
}

.toc-rail__progress {
  display: none;
}

/* ------------------------------------------------------------------
 * Variant: luma — round dot gliding along the rail
 * ---------------------------------------------------------------- */
.toc-rail[data-variant="luma"] .toc-rail__indicator {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  transform: translate(-50%, calc(var(--dot-y, 0px) - 50%));
  transition: transform 380ms cubic-bezier(0.22, 1, 0.36, 1), opacity 240ms ease;
}

.toc-rail[data-variant="luma"].is-moving .toc-rail__indicator {
  transform: translate(-50%, calc(var(--dot-y, 0px) - 50%)) scale(1.35);
}

/* ------------------------------------------------------------------
 * Variant: minimal — stretching capsule + bold hover pill
 * ---------------------------------------------------------------- */
.toc-rail[data-variant="minimal"] .toc-rail__indicator {
  width: 3px;
  border-radius: 999px;
  transform: translateY(0);
  margin-left: -1.5px;
}

.toc-rail[data-variant="minimal"] .toc-rail__link {
  padding-left: 10px;
  margin-left: -10px; /* hover pill hugs the text, not the rail */
}

.toc-rail[data-variant="minimal"] .toc-rail__link:hover {
  background: color-mix(in srgb, currentColor 9%, transparent);
}

@supports not (background: color-mix(in srgb, red 9%, transparent)) {
  .toc-rail[data-variant="minimal"] .toc-rail__link:hover {
    background: rgba(127, 127, 127, 0.12);
  }
}

.toc-rail[data-variant="minimal"] .toc-rail__link[aria-current] {
  color: var(--toc-rail-text-hover);
  font-weight: var(--font-weight-medium, 520);
}

/* ------------------------------------------------------------------
 * Variant: compact — dense, numbered, with progress fill
 * ---------------------------------------------------------------- */
.toc-rail[data-variant="compact"] {
  --toc-rail-width: 216px;
}

.toc-rail[data-variant="compact"] .toc-rail__indicator {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  border: 2px solid var(--bg-primary, #fff);
  box-sizing: border-box;
  transform: translate(-50%, calc(var(--dot-y, 0px) - 50%));
  transition: transform 320ms cubic-bezier(0.22, 1, 0.36, 1), opacity 240ms ease;
}

.toc-rail[data-variant="compact"] .toc-rail__progress {
  display: block;
  position: absolute;
  left: 0;
  top: 0;
  width: 1px;
  height: var(--progress-h, 0px);
  max-height: 100%;
  background: var(--toc-rail-accent);
  opacity: 0.45;
  transition: height 200ms ease-out;
}

.toc-rail[data-variant="compact"] .toc-rail__list {
  counter-reset: toc-section;
}

.toc-rail[data-variant="compact"] .toc-rail__link {
  font-size: 0.8125rem;
  padding-top: 3px;
  padding-bottom: 3px;
}

.toc-rail[data-variant="compact"] .toc-rail__item[data-level="2"] {
  counter-increment: toc-section;
}

.toc-rail[data-variant="compact"] .toc-rail__item[data-level="2"] .toc-rail__link::before {
  content: counter(toc-section, decimal-leading-zero);
  display: inline-block;
  min-width: 22px;
  font-variant-numeric: tabular-nums;
  font-size: 0.6875rem;
  letter-spacing: 0.04em;
  opacity: 0.55;
}

.toc-rail[data-variant="compact"] .toc-rail__item[data-level="3"] { padding-left: 22px; }
.toc-rail[data-variant="compact"] .toc-rail__item[data-level="4"] { padding-left: 36px; }

/* ------------------------------------------------------------------
 * Skeleton / loading state (no layout shift: geometry is identical)
 * ---------------------------------------------------------------- */
.toc-rail.is-loading .toc-rail__link {
  position: relative;
  color: transparent !important;
  pointer-events: none;
}

.toc-rail.is-loading .toc-rail__link::before {
  content: none !important;
}

.toc-rail.is-loading .toc-rail__link::after {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: var(--sk-w, 70%);
  height: 10px;
  border-radius: 999px;
  background: linear-gradient(
    100deg,
    var(--toc-rail-skeleton) 35%,
    var(--toc-rail-skeleton-sheen) 50%,
    var(--toc-rail-skeleton) 65%
  );
  background-size: 240% 100%;
  animation: toc-rail-shimmer 1.4s ease-in-out infinite;
}

.toc-rail[data-variant="minimal"].is-loading .toc-rail__link::after {
  left: 10px;
}

@keyframes toc-rail-shimmer {
  from { background-position: 120% 0; }
  to   { background-position: -120% 0; }
}

/* Text fades in as the skeleton clears */
.toc-rail.is-ready .toc-rail__link {
  animation: toc-rail-reveal 320ms ease both;
}

@keyframes toc-rail-reveal {
  from { opacity: 0.35; }
  to   { opacity: 1; }
}

.toc-rail.no-transition .toc-rail__indicator,
.toc-rail.no-transition .toc-rail__progress {
  transition: none !important;
}

@media (prefers-reduced-motion: reduce) {
  .toc-rail__indicator,
  .toc-rail__progress,
  .toc-rail__link {
    transition: none !important;
    animation: none !important;
  }
  .toc-rail.is-loading .toc-rail__link::after {
    animation: none;
  }
}

/* ------------------------------------------------------------------
 * Mobile / narrow viewport: collapsible "On this page" block
 * ---------------------------------------------------------------- */
.toc-mobile {
  display: none;
  margin: 1.5rem 0 2rem;
  border: 1px solid var(--toc-rail-line);
  border-radius: 10px;
  font-family: var(--font-family-ui, sans-serif);
}

@media (max-width: 1219px) {
  .toc-mobile {
    display: block;
  }
}

.toc-mobile__summary {
  cursor: pointer;
  list-style: none;
  padding: 12px 16px;
  font-size: 0.9375rem;
  font-weight: var(--font-weight-medium, 520);
  color: var(--toc-rail-text-hover);
  user-select: none;
}

.toc-mobile__summary::-webkit-details-marker {
  display: none;
}

.toc-mobile__summary::after {
  content: "+";
  float: right;
  color: var(--toc-rail-text);
  transition: transform 200ms ease;
}

.toc-mobile[open] .toc-mobile__summary::after {
  transform: rotate(45deg);
}

.toc-mobile__list {
  list-style: none;
  margin: 0;
  padding: 4px 16px 12px;
  border-top: 1px solid var(--toc-rail-line);
}

.toc-mobile__list li[data-level="3"] { padding-left: 16px; }
.toc-mobile__list li[data-level="4"] { padding-left: 32px; }

.toc-mobile__link {
  display: block;
  padding: 6px 0;
  color: var(--toc-rail-text);
  font-size: 0.9375rem;
  text-decoration: none;
  transition: color 160ms ease;
}

.toc-mobile__link:hover {
  color: var(--toc-rail-accent);
}

/* ==================================================================
 * TOC Minimap — collapsed depth bars; hover or "S" reveals a panel.
 * Variants: minimap (floating card), minimap-dock (pinned sidebar),
 * minimap-rail (panel styled like the luma rail).
 * ================================================================ */

.toc-minimap {
  position: fixed;
  top: 128px;
  left: 50%;
  transform: translateX(calc(var(--measure, 38em) / 2 + var(--toc-rail-gap)));
  z-index: 60;
  font-family: var(--font-family-ui, sans-serif);
}

@media (max-width: 1219px) {
  .toc-minimap {
    display: none;
  }
}

.toc-minimap__toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  margin: 0 0 6px -6px;
  padding: 0;
  border: 1px solid transparent;
  border-radius: 7px;
  background: transparent;
  color: var(--toc-rail-text);
  cursor: pointer;
  opacity: 0.55;
  transition: opacity 160ms ease, color 160ms ease,
    border-color 160ms ease, background-color 160ms ease;
}

.toc-minimap:hover .toc-minimap__toggle,
.toc-minimap__toggle:focus-visible {
  opacity: 1;
}

.toc-minimap__toggle:hover {
  color: var(--toc-rail-text-hover);
  background: rgba(127, 127, 127, 0.1);
}

.toc-minimap__toggle:focus-visible {
  outline: 2px solid var(--toc-rail-accent);
  outline-offset: 2px;
}

.toc-minimap.is-pinned .toc-minimap__toggle {
  opacity: 1;
  color: var(--toc-rail-text-hover);
  border-color: var(--toc-rail-line);
  background: rgba(127, 127, 127, 0.08);
}

/* --- collapsed depth bars --- */
.toc-minimap__bars {
  display: flex;
  flex-direction: column;
  gap: 9px;
  padding: 6px 0;
  max-height: 50vh;
  overflow: hidden;
  transition: opacity 200ms ease;
}

.toc-minimap__bar {
  height: 2px;
  width: 22px;
  border-radius: 2px;
  background: color-mix(in srgb, var(--toc-rail-text) 42%, transparent);
  transition: background-color 200ms ease, width 200ms ease;
}

@supports not (background: color-mix(in srgb, red 42%, transparent)) {
  .toc-minimap__bar {
    background: rgba(127, 127, 127, 0.38);
  }
}

.toc-minimap__bar[data-level="3"] { width: 14px; margin-left: 8px; }
.toc-minimap__bar[data-level="4"] { width: 8px; margin-left: 16px; }

.toc-minimap__bar[data-active] {
  background: var(--toc-rail-accent);
}

.toc-minimap.is-open .toc-minimap__bars {
  opacity: 0;
  pointer-events: none;
}

/* skeleton: bars shimmer while loading */
.toc-minimap.is-loading .toc-minimap__bar {
  animation: toc-minimap-breathe 1.4s ease-in-out infinite;
}

.toc-minimap.is-loading .toc-minimap__panel {
  display: none;
}

@keyframes toc-minimap-breathe {
  0%, 100% { opacity: 0.45; }
  50% { opacity: 1; }
}

/* --- panel shell --- */
.toc-minimap__panel {
  position: absolute;
  top: -10px;
  right: -14px;
  width: 248px;
  max-height: min(60vh, 540px);
  display: flex;
  visibility: hidden;
  opacity: 0;
  transform: translateX(6px);
  transition: opacity 180ms ease, transform 180ms cubic-bezier(0.22, 1, 0.36, 1),
    visibility 0s linear 180ms;
}

.toc-minimap.is-open .toc-minimap__panel {
  visibility: visible;
  opacity: 1;
  transform: translateX(0);
  transition: opacity 180ms ease, transform 180ms cubic-bezier(0.22, 1, 0.36, 1);
}

/* --- scrollable viewport with fading edges --- */
.toc-minimap__viewport {
  --fade-top: 0px;
  --fade-bottom: 0px;
  flex: 1;
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-width: none;
  padding: 14px 18px;
  -webkit-mask-image: linear-gradient(
    to bottom,
    transparent 0,
    #000 var(--fade-top),
    #000 calc(100% - var(--fade-bottom)),
    transparent 100%
  );
  mask-image: linear-gradient(
    to bottom,
    transparent 0,
    #000 var(--fade-top),
    #000 calc(100% - var(--fade-bottom)),
    transparent 100%
  );
}

.toc-minimap__viewport::-webkit-scrollbar {
  display: none;
}

.toc-minimap__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.toc-minimap__list li[data-level="3"] { padding-left: 14px; }
.toc-minimap__list li[data-level="4"] { padding-left: 28px; }

.toc-minimap__link {
  display: block;
  padding: 4px 0;
  color: var(--toc-rail-text);
  font-size: 0.875rem;
  line-height: 1.45;
  text-decoration: none;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  border-radius: 5px;
  transition: color 160ms ease;
}

.toc-minimap__link:hover {
  color: var(--toc-rail-text-hover);
}

.toc-minimap__link:focus-visible {
  outline: 2px solid var(--toc-rail-accent);
  outline-offset: 1px;
}

.toc-minimap__link[aria-current] {
  color: var(--toc-rail-text-hover);
  font-weight: var(--font-weight-medium, 520);
}

/* ------------------------------------------------------------------
 * Variant: minimap — floating hover-card
 * ---------------------------------------------------------------- */
.toc-minimap[data-variant="minimap"] .toc-minimap__panel {
  border: 1px solid var(--toc-rail-line);
  border-radius: 12px;
  background: var(--bg-primary, #fff);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.09), 0 2px 8px rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] .toc-minimap[data-variant="minimap"] .toc-minimap__panel {
  background: var(--dm-bg-secondary, #2d2d2d);
  box-shadow: 0 8px 28px rgba(0, 0, 0, 0.4);
}

/* ------------------------------------------------------------------
 * Variant: minimap-dock — pinned right-edge sidebar
 * ---------------------------------------------------------------- */
.toc-minimap[data-variant="minimap-dock"] .toc-minimap__panel {
  position: fixed;
  top: 84px;
  right: 0;
  bottom: auto;
  width: 264px;
  max-height: calc(100vh - 148px);
  border-left: 1px solid var(--toc-rail-line);
  background: var(--bg-primary, #fff);
  transform: translateX(12px);
}

[data-theme="dark"] .toc-minimap[data-variant="minimap-dock"] .toc-minimap__panel {
  background: var(--dm-bg-primary, #1a1a1a);
}

.toc-minimap[data-variant="minimap-dock"].is-open .toc-minimap__panel {
  transform: translateX(0);
}

.toc-minimap[data-variant="minimap-dock"] .toc-minimap__viewport {
  padding: 16px 24px;
}

/* ------------------------------------------------------------------
 * Variant: minimap-rail — panel styled like the luma rail
 * ---------------------------------------------------------------- */
.toc-minimap[data-variant="minimap-rail"] .toc-minimap__panel {
  background: var(--bg-primary, #fff);
}

[data-theme="dark"] .toc-minimap[data-variant="minimap-rail"] .toc-minimap__panel {
  background: var(--dm-bg-primary, #1a1a1a);
}

.toc-minimap[data-variant="minimap-rail"] .toc-minimap__list {
  border-left: 1px solid var(--toc-rail-line);
  padding-left: 18px;
}

.toc-minimap[data-variant="minimap-rail"] .toc-minimap__link {
  position: relative;
}

.toc-minimap[data-variant="minimap-rail"] .toc-minimap__link[aria-current] {
  color: var(--toc-rail-accent);
  font-weight: var(--font-weight-regular, 420);
}

.toc-minimap[data-variant="minimap-rail"] .toc-minimap__link[aria-current]::before {
  content: "";
  position: absolute;
  left: -21.5px;
  top: 50%;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--toc-rail-accent);
  transform: translateY(-50%);
}

@media (prefers-reduced-motion: reduce) {
  .toc-minimap__panel,
  .toc-minimap__bars,
  .toc-minimap__bar,
  .toc-minimap__link,
  .toc-minimap__toggle {
    transition: none !important;
    animation: none !important;
  }
}