/* =========================================================================
   docs.css — Editorial scholarly print stylesheet for /federated-learning/
   Type pairing: Fraunces (display) + Source Serif 4 (body) + IBM Plex Sans
   (chrome) + IBM Plex Mono (code). Editorial blue accent, hairline rules.
   Inks and surface tones consume site-wide tokens (assets/css/tokens.css)
   so home, federated-learning, and blog stay in sync.
   ========================================================================= */
@import url("/assets/css/tokens.css");

:root {
  /* Surfaces, ink, rules — sourced from site-wide tokens. */
  --paper:      var(--tk-paper);
  --paper-2:    var(--tk-paper-2);
  --ink:        var(--tk-ink);
  --ink-2:      var(--tk-ink-2);
  --mid:        var(--tk-mid);
  --mute:       var(--tk-mute);
  --rule:       var(--tk-rule);
  --rule-soft:  var(--tk-rule-soft);

  /* FL accent — editorial blue. Local to this room. */
  --oxblood:    #4A6FA5;
  --oxblood-2:  #2F4D7E;
  --tint:       #DCE6F2;
  --tint-soft:  #EEF3F9;

  --serif-display: "Fraunces", "Source Serif 4", Georgia, serif;
  --serif-body:    "Source Serif 4", "Iowan Old Style", Georgia, serif;
  --sans:          "IBM Plex Sans", -apple-system, BlinkMacSystemFont, sans-serif;
  --mono:          "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;

  --measure: 68ch;
  --gutter: 2.5rem;
  --rhythm: 1.7;
}

/* Dark mode: surfaces / ink come from tokens (slate-800 etc.); only the
   FL-local accent values change here. */
html.dark {
  --oxblood:   #93B5DC;
  --oxblood-2: #BACEE6;
  --tint:      #2C4D7A;
  --tint-soft: #233F66;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif-body);
  font-size: 1.0625rem;
  line-height: var(--rhythm);
  font-feature-settings: "kern", "liga", "onum", "calt";
  font-variant-numeric: oldstyle-nums proportional-nums;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Selection in oxblood for the personal flourish */
::selection { background: var(--oxblood); color: var(--paper); }

/* Scrollbars: thin, paper-toned */
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--rule); border-radius: 6px; border: 2px solid var(--paper); }
::-webkit-scrollbar-thumb:hover { background: var(--mute); }

/* =========================================================================
   Top bar — running head, not a SaaS nav
   ========================================================================= */
.runninghead {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in oklab, var(--paper) 88%, transparent);
  backdrop-filter: saturate(140%) blur(8px);
  -webkit-backdrop-filter: saturate(140%) blur(8px);
  border-bottom: 1px solid var(--rule);
}
.runninghead__inner {
  max-width: 76rem;
  margin: 0 auto;
  padding: 0.85rem 1.5rem;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 1.25rem;
  align-items: baseline;
}
.runninghead__mark {
  font-family: var(--serif-display);
  font-weight: 600;
  font-size: 0.95rem;
  letter-spacing: 0.01em;
  color: var(--ink);
  text-decoration: none;
}
.runninghead__crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: baseline;
  font-family: var(--sans);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--mid);
}
.runninghead__crumbs a {
  color: var(--mid);
  text-decoration: none;
  border-bottom: 1px dotted transparent;
  transition: color 0.15s, border-color 0.15s;
}
.runninghead__crumbs a:hover { color: var(--ink); border-bottom-color: var(--mid); }
.runninghead__crumbs .sep { color: var(--rule); }
.runninghead__crumbs .here {
  color: var(--ink);
  font-weight: 600;
}
.runninghead__status {
  margin-left: 0.6rem;
  padding: 0.1rem 0.5rem;
  border: 1px solid currentColor;
  border-radius: 999px;
  font-size: 0.62rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  font-weight: 600;
  line-height: 1.4;
  white-space: nowrap;
}
.runninghead__status::before {
  width: 5px; height: 5px;
  margin-right: 0.4rem;
  vertical-align: 0.08em;
  display: inline-block;
}
.runninghead__actions {
  display: flex;
  gap: 0.25rem;
  align-items: center;
}
.icon-btn {
  appearance: none;
  border: 0;
  background: transparent;
  color: var(--mid);
  width: 36px; height: 36px;
  border-radius: 4px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: color 0.15s, background-color 0.15s;
  text-decoration: none;
}
.icon-btn:hover { color: var(--ink); background: var(--paper-2); }
.icon-btn svg { width: 18px; height: 18px; }

/* =========================================================================
   Layout
   ========================================================================= */
.shell {
  max-width: 76rem;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 6rem;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--gutter);
}

@media (min-width: 1024px) {
  .shell {
    grid-template-columns: minmax(0, 1fr) 17rem;
    gap: 4rem;
  }
}

/* =========================================================================
   Article (the editorial column)
   ========================================================================= */
.editorial {
  max-width: var(--measure);
}

.editorial__kicker {
  font-family: var(--sans);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--oxblood);
  margin: 0 0 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.6rem;
}
.editorial__kicker::before,
.editorial__kicker::after {
  content: "";
  height: 1px;
  background: var(--oxblood);
  flex: 0 0 1.5rem;
}
.editorial__kicker::after { flex: 1 1 auto; }

.editorial__title {
  font-family: var(--serif-display);
  font-weight: 500;
  font-size: clamp(2.4rem, 5.5vw, 4.25rem);
  line-height: 1.02;
  letter-spacing: -0.018em;
  margin: 0 0 1.5rem;
  font-feature-settings: "kern", "liga", "ss01";
  font-variation-settings: "opsz" 144;
  color: var(--ink);
}

.editorial__lede {
  font-family: var(--serif-body);
  font-size: 1.3rem;
  line-height: 1.55;
  color: var(--ink-2);
  margin: 0 0 2rem;
  font-style: italic;
  font-weight: 400;
  max-width: 52ch;
}

.editorial__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 2rem 2.5rem;
  padding: 1.25rem 0 1.5rem;
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  margin-bottom: 3rem;
  font-family: var(--sans);
  font-size: 0.78rem;
  color: var(--mid);
}
.editorial__meta dt {
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-weight: 600;
  color: var(--mute);
  margin-bottom: 0.25rem;
}
.editorial__meta dd {
  margin: 0;
  color: var(--ink);
  font-family: var(--serif-body);
  font-size: 0.95rem;
}
.editorial__meta dd a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--rule);
  text-underline-offset: 0.18em;
  text-decoration-thickness: 1px;
}
.editorial__meta dd a:hover {
  text-decoration-color: var(--oxblood);
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.6rem;
  margin-top: 0.25rem;
}
.tags li {
  font-family: var(--sans);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--mid);
  padding: 0.18rem 0.55rem;
  border: 1px solid var(--rule);
  border-radius: 999px;
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--sans);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.status::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: currentColor;
  box-shadow: 0 0 0 3px color-mix(in oklab, currentColor 25%, transparent);
}
.status--draft       { color: #B8730B; }
.status--in_review   { color: var(--oxblood); }
.status--published   { color: #2F6F3D; }

/* =========================================================================
   Prose (Markdown body)
   ========================================================================= */
.prose {
  font-size: 1.0625rem;
  line-height: var(--rhythm);
  color: var(--ink);
}

.prose > * + * { margin-top: 1.1em; }
.prose > h2 + *, .prose > h3 + *, .prose > h4 + * { margin-top: 0.75em; }

.prose h2 {
  font-family: var(--serif-display);
  font-weight: 500;
  font-size: 2.05rem;
  line-height: 1.12;
  letter-spacing: -0.012em;
  margin-top: 3.5rem;
  margin-bottom: 1.25rem;
  color: var(--ink);
  font-variation-settings: "opsz" 60;
  position: relative;
  padding-bottom: 0.45rem;
  border-bottom: 1px solid var(--rule);
}
.prose h2::before {
  content: counter(h2-counter, decimal-leading-zero);
  counter-increment: h2-counter;
  position: absolute;
  right: 0;
  top: 0.6rem;
  font-family: var(--sans);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.18em;
  color: var(--mute);
}
.prose { counter-reset: h2-counter; }

.prose h3 {
  font-family: var(--serif-display);
  font-weight: 500;
  font-size: 1.4rem;
  line-height: 1.25;
  letter-spacing: -0.005em;
  margin-top: 2.5rem;
  margin-bottom: 0.75rem;
  color: var(--ink);
  font-variation-settings: "opsz" 36;
}

.prose h4 {
  font-family: var(--sans);
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-top: 2rem;
  margin-bottom: 0.5rem;
  color: var(--oxblood);
}

.prose p {
  margin: 1.1em 0;
  hyphens: auto;
  -webkit-hyphens: auto;
  text-wrap: pretty;
}

/* drop cap on the very first paragraph after the editorial header */
.prose > p:first-of-type::first-letter {
  font-family: var(--serif-display);
  font-weight: 500;
  float: left;
  font-size: 4.4rem;
  line-height: 0.85;
  padding: 0.4rem 0.75rem 0 0;
  color: var(--oxblood);
  font-variation-settings: "opsz" 144;
}

.prose a {
  color: inherit;
  text-decoration: underline;
  text-decoration-color: var(--rule);
  text-decoration-thickness: 1px;
  text-underline-offset: 0.22em;
  transition: text-decoration-color 0.15s, color 0.15s;
}
.prose a:hover {
  color: var(--oxblood);
  text-decoration-color: var(--oxblood);
  text-decoration-thickness: 2px;
}

/* citation links: superscript bracketed numerals, no underline */
.prose a[href^="#ref-"] {
  font-family: var(--sans);
  font-size: 0.62em;
  font-weight: 600;
  color: var(--oxblood);
  text-decoration: none;
  vertical-align: super;
  letter-spacing: 0.04em;
  padding: 0 0.05em;
  font-variant-numeric: lining-nums;
}
.prose a[href^="#ref-"]:hover {
  color: var(--oxblood-2);
  text-decoration: underline;
  text-decoration-thickness: 1px;
}

.prose ul, .prose ol {
  padding-left: 1.5rem;
  margin: 1.1em 0;
}
.prose ul { list-style: none; }
.prose ul > li { position: relative; }
.prose ul > li::before {
  content: "";
  position: absolute;
  left: -1.05rem;
  top: 0.7em;
  width: 0.4rem;
  height: 1px;
  background: var(--oxblood);
}
.prose ol { list-style: decimal; }
.prose ol::marker, .prose ol > li::marker {
  color: var(--mute);
  font-family: var(--sans);
  font-variant-numeric: lining-nums;
}
.prose li { margin: 0.45em 0; }
.prose li > p { margin: 0.45em 0; }

.prose blockquote {
  margin: 1.75rem 0;
  padding: 0.5rem 1.5rem;
  border-left: 2px solid var(--oxblood);
  background: var(--paper-2);
  font-style: italic;
  color: var(--ink-2);
  font-size: 1rem;
}
.prose blockquote p:first-child { margin-top: 0; }
.prose blockquote p:last-child  { margin-bottom: 0; }

.prose hr {
  border: 0;
  text-align: center;
  margin: 3rem 0;
  height: 1.2em;
  position: relative;
}
.prose hr::before {
  content: "✦";
  color: var(--oxblood);
  font-size: 0.9rem;
  letter-spacing: 0.5em;
}

.prose figure { margin: 2.5rem 0; }
.prose figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--rule);
  background: var(--paper-2);
}
.prose figcaption {
  margin-top: 0.65rem;
  font-family: var(--sans);
  font-size: 0.78rem;
  color: var(--mid);
  text-align: left;
  border-top: 1px solid var(--rule);
  padding-top: 0.4rem;
  letter-spacing: 0.01em;
}

.prose code {
  font-family: var(--mono);
  font-size: 0.86em;
  background: var(--paper-2);
  padding: 0.12em 0.35em;
  border: 1px solid var(--rule-soft);
  color: var(--ink);
  border-radius: 2px;
}
.prose pre {
  font-family: var(--mono);
  font-size: 0.85rem;
  line-height: 1.6;
  background: var(--paper-2);
  color: var(--ink);
  padding: 1rem 1.25rem;
  border: 1px solid var(--rule);
  border-left: 3px solid var(--oxblood);
  overflow-x: auto;
  margin: 1.6rem 0;
  border-radius: 2px;
}
.prose pre code {
  background: transparent;
  border: 0;
  padding: 0;
  font-size: inherit;
}

/* tables: editorial / scientific */
.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.75rem 0;
  font-size: 0.92rem;
  font-variant-numeric: tabular-nums lining-nums;
  font-family: var(--serif-body);
}
.prose th, .prose td {
  padding: 0.6rem 0.85rem;
  border-bottom: 1px solid var(--rule);
  text-align: left;
  vertical-align: top;
}
.prose th {
  border-bottom: 2px solid var(--ink);
  font-family: var(--sans);
  font-size: 0.74rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink);
}
.prose tr:hover td { background: var(--paper-2); }

/* tool-link inline pill */
.prose a.tool {
  display: inline-block;
  font-family: var(--sans);
  font-size: 0.78em;
  letter-spacing: 0.04em;
  padding: 0.05em 0.45em;
  background: var(--tint-soft);
  color: var(--oxblood-2);
  border-radius: 2px;
  text-decoration: none;
  border-bottom: 1px solid var(--oxblood);
}
.prose a.tool:hover {
  background: var(--oxblood);
  color: var(--paper);
  border-bottom-color: var(--oxblood-2);
}

/* Bibliography list */
.prose h2#bibliography + ol,
.prose h2 + ol:last-of-type {
  font-size: 0.92rem;
  line-height: 1.55;
  padding-left: 2rem;
}
.prose ol li[id^="ref-"], .prose li > span[id^="ref-"] {
  scroll-margin-top: 5rem;
}

/* =========================================================================
   Sidebar (TOC + page card)
   ========================================================================= */
.aside {
  display: none;
  font-family: var(--sans);
}

@media (min-width: 1024px) {
  .aside {
    display: block;
    position: sticky;
    top: 5rem;
    align-self: start;
    max-height: calc(100vh - 6rem);
    overflow-y: auto;
    overflow-x: hidden;
    padding-right: 0.5rem;
    padding-bottom: 2rem;
    scroll-behavior: smooth;
    scrollbar-width: thin;
    scrollbar-color: var(--rule) transparent;
  }
  .aside::-webkit-scrollbar { width: 6px; }
  .aside::-webkit-scrollbar-track { background: transparent; }
  .aside::-webkit-scrollbar-thumb { background: var(--rule); border-radius: 3px; }
  .aside:hover::-webkit-scrollbar-thumb { background: var(--mute); }
}

.aside section + section {
  margin-top: 2.5rem;
  padding-top: 2rem;
  border-top: 1px solid var(--rule);
}

.aside__label {
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mute);
  margin: 0 0 1rem;
}

.aside__contributor {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  font-size: 0.85rem;
  margin: 0.4rem 0;
}
.aside__contributor .initials {
  width: 32px; height: 32px;
  border-radius: 50%;
  background: var(--ink);
  color: var(--paper);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  font-feature-settings: "lnum";
  flex-shrink: 0;
}
.aside__contributor .avatar {
  width: 32px; height: 32px;
  border-radius: 50%;
  object-fit: cover;
  border: 1px solid var(--rule);
  background: var(--paper-2);
  flex-shrink: 0;
}
.aside__contributor a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 1px dotted var(--rule);
}
.aside__contributor a:hover {
  border-bottom-color: var(--oxblood);
  color: var(--oxblood);
}
.aside__contributor .affil {
  display: block;
  font-size: 0.7rem;
  color: var(--mid);
  margin-top: 0.05rem;
}

.aside__updated {
  margin-top: 1.25rem;
  padding-top: 0.85rem;
  border-top: 1px solid var(--rule);
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  color: var(--mute);
}
.aside__updated time {
  color: var(--ink-2);
  font-feature-settings: "lnum";
}

/* TOC: always-visible nested tree, fluid scroll, no toggle clutter */
.toc {
  padding: 0;
  margin: 0;
  list-style: none;
  border-left: 1px solid var(--rule);
}
.toc__group { position: relative; }
.toc__sub {
  list-style: none;
  padding: 0;
  margin: 0;
}
.toc__link {
  display: block;
  padding: 0.32rem 0 0.32rem 1rem;
  margin-left: -1px;
  border-left: 2px solid transparent;
  font-size: 0.85rem;
  font-family: var(--sans);
  color: var(--mid);
  text-decoration: none;
  line-height: 1.45;
  transition: color 0.15s ease, border-left-color 0.15s ease, background-color 0.15s ease;
}
.toc__link--h2 {
  font-weight: 500;
  color: var(--ink-2);
}
.toc__link--h3 {
  padding-left: 1.75rem;
  font-size: 0.8rem;
  color: var(--mid);
}
.toc__link:hover {
  color: var(--ink);
  border-left-color: var(--mid);
  background: var(--rule-soft);
}
.toc__link.is-active {
  color: var(--oxblood);
  border-left-color: var(--oxblood);
  font-weight: 500;
  background: var(--tint-soft);
}
.toc__link--h2.is-active { font-weight: 600; }

/* Sibling pages */
.siblings { padding: 0; margin: 0; list-style: none; }
.siblings li + li { margin-top: 0.45rem; }
.siblings a {
  display: block;
  font-size: 0.85rem;
  color: var(--mid);
  text-decoration: none;
  padding: 0.25rem 0;
  border-bottom: 1px solid transparent;
  transition: color 0.15s, border-bottom-color 0.15s;
}
.siblings a:hover { color: var(--ink); border-bottom-color: var(--rule); }
.siblings a[aria-current="page"] {
  color: var(--oxblood);
  font-weight: 600;
  border-bottom-color: var(--oxblood);
}
.siblings a .num {
  font-family: var(--sans);
  font-size: 0.7rem;
  color: var(--mute);
  margin-right: 0.6rem;
  font-feature-settings: "lnum";
}

/* =========================================================================
   Hero — animated FL topology (main page only)
   ========================================================================= */
.topology {
  max-width: var(--measure);
  margin: 2rem 0 2.5rem;
  padding: 0;
  position: relative;
}
.topology__svg {
  display: block;
  width: 100%;
  height: auto;
  max-height: 280px;
}
.topology__caption {
  margin-top: 0.75rem;
  padding-top: 0;
  border-top: 0;
  font-family: var(--sans);
  font-size: 0.74rem;
  color: var(--mid);
  letter-spacing: 0.04em;
  text-align: center;
}
.topology__caption b {
  color: var(--oxblood);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-size: 0.68rem;
  margin-right: 0.4rem;
}

.topology__svg .node-coord { fill: var(--ink); }
.topology__svg .node-client { fill: var(--paper); stroke: var(--ink); stroke-width: 1.3; }
.topology__svg .label {
  font-family: var(--sans);
  font-size: 9px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  fill: var(--mid);
}
.topology__svg .label-coord { fill: var(--oxblood); font-weight: 600; }
.topology__svg .axis { stroke: var(--rule); stroke-width: 1; }
.topology__svg .upd-line {
  fill: none;
  stroke: var(--oxblood);
  stroke-width: 1.4;
  stroke-dasharray: 3 3;
  stroke-linecap: round;
  opacity: 0.6;
  animation: pulse-in 3.2s ease-in-out infinite;
}
.topology__svg .upd-line:nth-child(2) { animation-delay: 0.0s; }
.topology__svg .upd-line:nth-child(3) { animation-delay: 0.4s; }
.topology__svg .upd-line:nth-child(4) { animation-delay: 0.8s; }
.topology__svg .upd-line:nth-child(5) { animation-delay: 1.2s; }
.topology__svg .upd-line:nth-child(6) { animation-delay: 1.6s; }
.topology__svg .agg-pulse {
  fill: none;
  stroke: var(--oxblood);
  stroke-width: 1.5;
  opacity: 0;
  animation: agg-pulse 3.2s ease-out infinite;
}

@keyframes pulse-in {
  0%   { opacity: 0; stroke-dashoffset: 30; }
  20%  { opacity: 0.8; }
  60%  { opacity: 0.5; stroke-dashoffset: 0; }
  100% { opacity: 0; stroke-dashoffset: -10; }
}
@keyframes agg-pulse {
  0%   { r: 14; opacity: 0.5; }
  100% { r: 86; opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  .topology__svg .upd-line,
  .topology__svg .agg-pulse { animation: none; opacity: 0.45; }
}

/* =========================================================================
   Footer
   ========================================================================= */
.colophon {
  max-width: 76rem;
  margin: 0 auto;
  padding: 4rem 1.5rem 2rem;
  border-top: 1px solid var(--rule);
  font-family: var(--sans);
  font-size: 0.78rem;
  color: var(--mid);
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}
@media (min-width: 720px) {
  .colophon { grid-template-columns: 1.5fr 1fr 1fr; }
}
.colophon h6 {
  margin: 0 0 0.4rem;
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mute);
}
.colophon p { margin: 0.2rem 0; line-height: 1.55; }
.colophon a {
  color: var(--ink);
  text-decoration: underline;
  text-decoration-color: var(--rule);
  text-underline-offset: 0.18em;
}
.colophon a:hover { text-decoration-color: var(--oxblood); color: var(--oxblood); }

/* =========================================================================
   Mobile back link
   ========================================================================= */
.mobile-back {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-family: var(--sans);
  font-size: 0.8rem;
  color: var(--mid);
  text-decoration: none;
  margin-bottom: 1.5rem;
  letter-spacing: 0.04em;
}
.mobile-back:hover { color: var(--oxblood); }
@media (min-width: 1024px) { .mobile-back { display: none; } }

/* =========================================================================
   Print
   ========================================================================= */
@media print {
  .runninghead, .aside, .colophon, .topology, .icon-btn, .mobile-back { display: none !important; }
  .shell { grid-template-columns: 1fr; padding: 0; max-width: none; }
  .editorial { max-width: none; }
  body { background: white; color: black; font-size: 10pt; }
  .prose a[href^="#ref-"] { color: black; }
  .prose a:not([href^="#"])::after {
    content: " (" attr(href) ")";
    font-size: 0.78em;
    color: #555;
    word-wrap: break-word;
  }
  .prose h2 { break-after: avoid; }
  .prose h3, .prose h4 { break-after: avoid; }
  .prose p, .prose li { orphans: 3; widows: 3; }
}