/* Design tokens carried over from the study folder so the handbook reads as
   part of the same system rather than a separate site. */
:root {
  --ground: #f5f7fa; --panel: #fff; --panel-2: #edf1f6;
  --ink: #0f1620; --ink-2: #3d4a5c; --ink-3: #6b788a;
  --rule: #d3dbe5; --rule-2: #e5eaf1;
  /* hairline border width. Used 33 times across this file and never defined,
     which silently resolved every one of those borders to none. */
  --hair: 1px;
  --signal: #1f4e79; --signal-ink: #153a5b; --signal-wash: #e4edf6;
  --caution: #b15a08; --caution-wash: #fbeee0;
  --good: #1b6647; --good-wash: #e2f0ea;
  --bad: #a32b26; --bad-wash: #f8e6e5;
  --sans: "IBM Plex Sans", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "IBM Plex Mono", ui-monospace, Consolas, monospace;
  --display: "Barlow Condensed", var(--sans);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --ground: #0c1219; --panel: #131c26; --panel-2: #1a2532;
    --ink: #e6ecf3; --ink-2: #aebbcb; --ink-3: #7e8da0;
    --rule: #26333f; --rule-2: #1e2a36;
    --signal: #7fb2e0; --signal-ink: #a9ccec; --signal-wash: #152534;
    --caution: #e5a15c; --caution-wash: #2c2116;
    --good: #6fc49b; --good-wash: #122620;
    --bad: #e8867f; --bad-wash: #2a1817;
  }
}
:root[data-theme="dark"] {
  --ground: #0c1219; --panel: #131c26; --panel-2: #1a2532;
  --ink: #e6ecf3; --ink-2: #aebbcb; --ink-3: #7e8da0;
  --rule: #26333f; --rule-2: #1e2a36;
  --signal: #7fb2e0; --signal-ink: #a9ccec; --signal-wash: #152534;
  --caution: #e5a15c; --caution-wash: #2c2116;
  --good: #6fc49b; --good-wash: #122620;
  --bad: #e8867f; --bad-wash: #2a1817;
}

* { box-sizing: border-box; }
body {
  margin: 0; background: var(--ground); color: var(--ink);
  font-family: var(--sans); font-size: 16px; line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--signal); }
:focus-visible { outline: 2px solid var(--signal); outline-offset: 2px; border-radius: 3px; }
.skip { position: absolute; left: -9999px; top: 8px; z-index: 60;
  background: var(--signal); color: #fff; padding: 8px 14px; border-radius: 6px; }
.skip:focus { left: 12px; }

/* ------------------------------------------------------------------ topbar */
.topbar {
  position: sticky; top: 0; z-index: 40;
  display: flex; align-items: center; gap: 14px;
  padding: 10px 18px; background: var(--panel);
  border-bottom: 1px solid var(--rule);
}
.brand {
  font-family: var(--display); font-weight: 700; font-size: 21px;
  letter-spacing: .02em; color: var(--ink); text-decoration: none; white-space: nowrap;
}
.menu-btn, .theme-btn {
  background: transparent; border: 1px solid var(--rule); color: var(--ink-2);
  border-radius: 6px; height: 34px; min-width: 34px; cursor: pointer; font-size: 15px;
}
.menu-btn { display: none; }
.theme-btn:hover, .menu-btn:hover { border-color: var(--signal); color: var(--signal); }

.search-wrap { position: relative; flex: 1; max-width: 460px; margin-left: auto; }
#search {
  width: 100%; height: 34px; padding: 0 12px;
  background: var(--ground); color: var(--ink);
  border: 1px solid var(--rule); border-radius: 6px;
  font-family: var(--sans); font-size: 14px;
}
.results {
  position: absolute; top: 40px; left: 0; right: 0; max-height: 62vh; overflow-y: auto;
  background: var(--panel); border: 1px solid var(--rule); border-radius: 8px;
  box-shadow: 0 12px 32px rgba(0, 0, 0, .18); padding: 6px;
}
.results a { display: block; padding: 8px 10px; border-radius: 6px; text-decoration: none; color: var(--ink); }
.results a:hover, .results a.sel { background: var(--signal-wash); }
.results .r-title { font-weight: 600; font-size: 14px; }
.results .r-ctx { font-size: 12.5px; color: var(--ink-3); }
.results mark { background: var(--caution-wash); color: inherit; padding: 0 2px; border-radius: 2px; }
.results .empty { padding: 12px; color: var(--ink-3); font-size: 14px; }

/* ------------------------------------------------------------------- shell */
.shell { display: grid; grid-template-columns: 262px minmax(0, 1fr) 210px; gap: 30px;
  max-width: 1400px; margin: 0 auto; padding: 26px 22px 90px; align-items: start; }

.sidebar { position: sticky; top: 74px; max-height: calc(100vh - 100px); overflow-y: auto; }
.nav-group { margin-bottom: 18px; }
.nav-group-title {
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .12em;
  text-transform: uppercase; color: var(--ink-3); margin-bottom: 6px;
}
.sidebar ul { list-style: none; margin: 0; padding: 0; }
.sidebar li a {
  display: block; padding: 5px 10px; border-left: 2px solid var(--rule-2);
  color: var(--ink-2); text-decoration: none; font-size: 14.5px;
}
.sidebar li a:hover { color: var(--ink); border-left-color: var(--ink-3); }
.sidebar li a.active { color: var(--signal); border-left-color: var(--signal); font-weight: 600; }
.badge { font-family: var(--mono); font-size: 9.5px; text-transform: uppercase;
  padding: 1px 5px; border-radius: 99px; margin-left: 6px; vertical-align: middle; }
.badge.draft { background: var(--caution-wash); color: var(--caution); }

/* -------------------------------------------------------------------- toc */
.toc { position: sticky; top: 74px; max-height: calc(100vh - 100px); overflow-y: auto; font-size: 13.5px; }
.toc-title { font-family: var(--mono); font-size: 10.5px; letter-spacing: .12em;
  text-transform: uppercase; color: var(--ink-3); margin-bottom: 6px; }
.toc ul { list-style: none; margin: 0; padding: 0; }
.toc li a { display: block; padding: 3px 0 3px 10px; border-left: 2px solid var(--rule-2);
  color: var(--ink-3); text-decoration: none; }
.toc li.d3 a { padding-left: 20px; font-size: 12.5px; }
.toc li a:hover { color: var(--ink); }
.toc li a.active { color: var(--signal); border-left-color: var(--signal); }

/* ------------------------------------------------------------------- prose */
.prose { background: var(--panel); border: 1px solid var(--rule);
  border-radius: 10px; padding: 34px 38px; min-width: 0; }
.prose h1 { font-family: var(--display); font-size: 38px; line-height: 1.12;
  margin: 0 0 10px; letter-spacing: .01em; }
.prose h2 { font-family: var(--display); font-size: 27px; margin: 38px 0 12px;
  padding-top: 16px; border-top: 1px solid var(--rule-2); letter-spacing: .01em; }
.prose h3 { font-size: 18.5px; margin: 26px 0 8px; }
.prose h4 { font-size: 15.5px; margin: 20px 0 6px; color: var(--ink-2); }
.anchor { float: left; margin-left: -0.85em; padding-right: .3em; color: var(--rule);
  text-decoration: none; opacity: 0; }
h2:hover .anchor, h3:hover .anchor { opacity: 1; }
.prose p { margin: 0 0 14px; }
.prose ul, .prose ol { margin: 0 0 14px; padding-left: 22px; }
.prose li { margin-bottom: 5px; }
.prose blockquote { margin: 0 0 16px; padding: 10px 16px; border-left: 3px solid var(--signal);
  background: var(--signal-wash); border-radius: 0 6px 6px 0; color: var(--ink-2); }
.prose blockquote p:last-child { margin-bottom: 0; }
.prose hr { border: 0; border-top: 1px solid var(--rule); margin: 34px 0; }
.prose code { font-family: var(--mono); font-size: .86em; background: var(--panel-2);
  padding: 1px 5px; border-radius: 4px;
  overflow-wrap: anywhere; }
.prose pre.code { background: var(--panel-2); border: 1px solid var(--rule-2);
  border-radius: 8px; padding: 14px 16px; overflow-x: auto; margin: 0 0 16px; }
.prose pre.code code { background: none; padding: 0; font-size: 13px; line-height: 1.55; }
pre.mermaid { background: var(--panel-2); border: 1px solid var(--rule-2); border-radius: 8px;
  padding: 16px; margin: 0 0 18px; text-align: center; overflow-x: auto; }

.table-scroll { overflow-x: auto; margin: 0 0 18px; }
.prose table { border-collapse: collapse; width: 100%; font-size: 14.5px; }
.prose th, .prose td { border: 1px solid var(--rule); padding: 7px 11px;
  text-align: left; vertical-align: top; }
.prose th { background: var(--panel-2); font-weight: 600; }

/* Callouts, driven by a leading bold marker in the markdown. */
.prose .callout { border-radius: 8px; padding: 12px 16px; margin: 0 0 16px; border: 1px solid; }
.callout.note { background: var(--signal-wash); border-color: var(--signal); }
.callout.warn { background: var(--caution-wash); border-color: var(--caution); }
.callout.good { background: var(--good-wash); border-color: var(--good); }
.callout.bad { background: var(--bad-wash); border-color: var(--bad); }

/* ------------------------------------------------------------------ pager */
.pager-row { display: flex; gap: 12px; margin-top: 22px; }
.pager { flex: 1; padding: 12px 16px; border: 1px solid var(--rule); border-radius: 8px;
  background: var(--panel); text-decoration: none; color: var(--ink); font-weight: 600; font-size: 14.5px; }
.pager span { display: block; font-family: var(--mono); font-size: 10.5px; letter-spacing: .1em;
  text-transform: uppercase; color: var(--ink-3); font-weight: 400; }
.pager.next { text-align: right; }
.pager:hover { border-color: var(--signal); }

/* ------------------------------------------------------------- responsive */
@media (max-width: 1180px) {
  .shell { grid-template-columns: 240px minmax(0, 1fr); }
  .toc { display: none; }
}
@media (max-width: 820px) {
  .shell { grid-template-columns: minmax(0, 1fr); padding: 18px 14px 70px; }
  .menu-btn { display: block; }
  .sidebar { display: none; position: fixed; inset: 56px 0 auto 0; z-index: 35;
    background: var(--panel); border-bottom: 1px solid var(--rule);
    padding: 16px 18px; max-height: 74vh; }
  .sidebar.open { display: block; }
  .prose { padding: 22px 18px; }
  .prose h1 { font-size: 30px; }
  .brand { font-size: 18px; }
}
/* ------------------------------------------------------------------ motion
   Interaction feedback only: things that already change on hover, focus or
   open now travel there instead of snapping. Nothing here moves on its own,
   and nothing is hidden waiting for a trigger -- the page at rest is the page
   in full. The reduced-motion guard at the bottom neutralises all of it. */
html { scroll-behavior: smooth; }

a, .sidebar li a, .toc li a, .pager, .menu-btn, .theme-btn,
.results a, .anchor, #search {
  transition: color .16s ease, background-color .16s ease,
              border-color .16s ease, opacity .16s ease;
}
.pager { transition: color .16s ease, border-color .16s ease,
                     box-shadow .18s ease, transform .18s ease; }
.pager:hover { transform: translateY(-2px); box-shadow: 0 6px 18px rgba(0, 0, 0, .09); }
.menu-btn:active, .theme-btn:active { transform: scale(.94); }
#search:focus { border-color: var(--signal); box-shadow: 0 0 0 3px var(--signal-wash); }

/* The dropdown is created on keystroke, so it animates in rather than appearing. */
.results { animation: drop-in .14s ease-out; transform-origin: top center; }
@keyframes drop-in {
  from { opacity: 0; transform: translateY(-4px) scale(.99); }
  to   { opacity: 1; transform: none; }
}
.sidebar.open { animation: drop-in .16s ease-out; }

/* Heading anchors fade rather than blink. */
.anchor { transition: opacity .18s ease, color .18s ease; }
h2:hover .anchor, h3:hover .anchor { color: var(--ink-3); }

/* Sticky nav marks where you are; let the marker slide between entries. */
.sidebar li a, .toc li a { transition: color .16s ease, border-left-color .22s ease; }

/* ------------------------------------------------------- animated diagrams
   Figures that show a process over time. The markup lives in the markdown as
   plain SVG; the timing lives here so the reduced-motion guard can switch it
   off, and so colours come from the same tokens as the rest of the page. */
.fig-anim {
  margin: 0 0 18px; padding: 18px 16px 12px;
  background: var(--panel-2); border: 1px solid var(--rule-2); border-radius: 8px;
}
.fig-anim svg { display: block; width: 100%; height: auto; color: var(--ink-2); }
.fig-anim figcaption {
  margin-top: 10px; font-size: 13.5px; line-height: 1.5; color: var(--ink-3);
}
.fig-anim .lbl { font-family: var(--mono); font-size: 10.5px; fill: var(--ink-3); }
.fig-anim .lbl-b { font-family: var(--mono); font-size: 11px; fill: var(--ink-2); font-weight: 500; }
.fig-anim .slot { fill: none; stroke: var(--rule); stroke-width: 1; }
.fig-anim .k { fill: var(--signal); }
.fig-anim .v { fill: var(--caution); }
.fig-anim .ok { fill: var(--good); }
.fig-anim .no { fill: var(--bad); }

/* 1 - the cache filling: prefill lands as a block, decode adds one slot a
   time, then the cycle restarts. Each cell carries its own delay inline. */
.kv-fill { opacity: 0; animation: kv-appear 8s linear infinite; }
@keyframes kv-appear {
  0%   { opacity: 0; transform: scaleY(.4); }
  3%   { opacity: 1; transform: scaleY(1); }
  88%  { opacity: 1; transform: scaleY(1); }
  96%  { opacity: 0; transform: scaleY(.4); }
  100% { opacity: 0; transform: scaleY(.4); }
}
.kv-fill { transform-box: fill-box; transform-origin: bottom; }

/* 2 - allocation: a four-block request probes contiguous memory, finds no run
   long enough, and is rejected; the same request lands immediately in paged
   memory because every free block is interchangeable. */
.probe { animation: probe-slide 8s ease-in-out infinite; }
@keyframes probe-slide {
  0%,  8%  { transform: translateX(0);     opacity: 0; }  /* over the 2-block gap */
  14%, 34% { transform: translateX(0);     opacity: 1; }
  46%, 92% { transform: translateX(204px); opacity: 1; }  /* the other 2-block gap */
  98%,100% { transform: translateX(204px); opacity: 0; }
}
.probe-body { fill: var(--bad); opacity: .28; stroke: var(--bad); stroke-width: 1; }
.reject { opacity: 0; animation: reject-flash 8s ease-in-out infinite; }
@keyframes reject-flash {
  0%, 70%   { opacity: 0; }
  76%, 88%  { opacity: 1; }
  94%, 100% { opacity: 0; }
}
.claim { opacity: 0; animation: claim-in 8s ease-in-out infinite; }
@keyframes claim-in {
  0%, 12%  { opacity: 0; transform: scale(.5); }
  20%      { opacity: 1; transform: scale(1); }
  90%      { opacity: 1; transform: scale(1); }
  96%,100% { opacity: 0; transform: scale(.5); }
}
.claim { transform-box: fill-box; transform-origin: center; }


/* ============================================================================
   WIDGETS
   Every one is the live twin of a Python block on the same page, so it is
   styled as a sibling of pre.code rather than as a feature: same surface, same
   border, same corner. The interaction is the only thing that differs.
   ========================================================================== */
.widget {
  background: var(--panel-2);
  border: var(--hair) solid var(--rule-2);
  border-radius: 8px;
  padding: 16px 18px;
  margin: 0 0 18px;
}
.widget__fallback { margin: 0; font-size: 14px; color: var(--ink-3); }

.widget__head {
  display: flex; align-items: baseline; gap: 10px;
  padding-bottom: 12px; margin-bottom: 14px;
  border-bottom: var(--hair) solid var(--rule-2);
}
.widget__tag {
  font-family: var(--mono); font-size: 9.5px; letter-spacing: .12em;
  text-transform: uppercase; color: var(--signal);
  border: var(--hair) solid var(--signal); border-radius: 99px;
  padding: 2px 7px; flex: none;
}
.widget__title { font-weight: 600; font-size: 15px; }

.widget__controls { display: grid; gap: 12px 22px; }
@media (min-width: 620px) { .widget__controls { grid-template-columns: 1fr 1fr; } }

.widget__ctl { display: grid; gap: 4px; min-width: 0; }
.widget__lab {
  display: flex; justify-content: space-between; align-items: baseline; gap: 10px;
  font-family: var(--mono); font-size: 11px; letter-spacing: .06em;
  text-transform: uppercase; color: var(--ink-3);
}
.widget__val { color: var(--ink); font-weight: 500; font-variant-numeric: tabular-nums; }

.widget__input { width: 100%; accent-color: var(--signal); }
select.widget__input {
  font-family: var(--mono); font-size: 12px;
  background: var(--panel); color: var(--ink);
  border: var(--hair) solid var(--rule); border-radius: 5px; padding: 4px 6px;
}
.widget__input:focus-visible { outline: 2px solid var(--signal); outline-offset: 2px; }

.widget__out {
  margin-top: 16px; padding-top: 14px;
  border-top: var(--hair) solid var(--rule-2);
}
.widget__big {
  display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap;
  margin-bottom: 10px;
}
.widget__big b {
  font-family: var(--display); font-size: 30px; line-height: 1;
  letter-spacing: .01em; color: var(--signal); font-variant-numeric: tabular-nums;
}
.widget__big span { font-size: 13.5px; color: var(--ink-3); }
.widget__big.is-ok  b { color: var(--good); }
.widget__big.is-warn b { color: var(--caution); }
.widget__big.is-bad b { color: var(--bad); }

.widget__row {
  display: flex; justify-content: space-between; gap: 14px;
  padding: 4px 0; font-size: 13.5px; color: var(--ink-2);
  border-bottom: var(--hair) solid var(--rule-2);
}
.widget__row:last-child { border-bottom: 0; }
.widget__row b { font-family: var(--mono); color: var(--ink); font-variant-numeric: tabular-nums; }
.widget__row.is-ok  b { color: var(--good); }
.widget__row.is-warn b { color: var(--caution); }
.widget__row.is-bad b { color: var(--bad); }

/* the pipeline-bubble bar: work vs idle */
.widget__bar { display: flex; height: 12px; border-radius: 3px; overflow: hidden; margin: 10px 0 12px; }
.widget__bar i { background: var(--signal); }
.widget__bar u { background: var(--bad); opacity: .55; }

/* the softmax weight bars */
.widget__wrow {
  display: grid; grid-template-columns: 52px 1fr 56px;
  align-items: center; gap: 10px; padding: 3px 0; font-size: 13.5px;
}
.widget__wrow span { font-family: var(--mono); color: var(--ink-3); }
.widget__wrow b { font-family: var(--mono); text-align: right; font-variant-numeric: tabular-nums; }
.widget__wbar { background: var(--rule-2); border-radius: 3px; height: 10px; overflow: hidden; }
.widget__wbar i { display: block; height: 100%; background: var(--signal); }

.widget--failed { display: none; }

@media (prefers-reduced-motion: reduce) { .widget__wbar i, .widget__bar i { transition: none; } }
@media print { .widget { display: none; } }

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: .01ms !important; transition-duration: .01ms !important; }
  html { scroll-behavior: auto; }
  /* Held at the end state so the figures still read as finished pictures. */
  .kv-fill, .claim, .reject { opacity: 1 !important; }
  .probe { opacity: 1 !important; }
}


/* ============================================================================
   LABS
   A widget moves a slider over a formula; a lab runs the page's real algorithm
   on text the reader types. Visually it is the widget's louder sibling: same
   family, wider, with room for inputs and a result area that can hold a grid,
   a bar chart or a wall of chips.
   ========================================================================== */
.lab {
  background: var(--panel);
  border: var(--hair) solid var(--rule);
  border-radius: 8px;
  padding: 18px 20px;
  margin: 0 0 20px;
}
.lab__fallback { margin: 0; font-size: 14px; color: var(--ink-3); }
.lab--failed { display: none; }

.lab__head {
  display: flex; align-items: baseline; gap: 10px;
  padding-bottom: 12px; border-bottom: var(--hair) solid var(--rule-2);
}
.lab__tag {
  font-family: var(--mono); font-size: 9.5px; letter-spacing: .12em;
  text-transform: uppercase; color: var(--caution); flex: none;
  border: var(--hair) solid var(--caution); border-radius: 99px; padding: 2px 7px;
}
.lab__title { font-weight: 600; font-size: 15.5px; }
.lab__note {
  margin: 12px 0 0; font-size: 14px; line-height: 1.55; color: var(--ink-2);
  max-width: 76ch;
}

.lab__controls { display: grid; gap: 12px 20px; margin-top: 16px; }
@media (min-width: 640px) { .lab__controls { grid-template-columns: 1fr 1fr; } }
.lab__field { display: grid; gap: 5px; min-width: 0; }
.lab__field--wide { grid-column: 1 / -1; }
.lab__lab {
  display: flex; justify-content: space-between; align-items: baseline; gap: 10px;
  font-family: var(--mono); font-size: 10.5px; letter-spacing: .06em;
  text-transform: uppercase; color: var(--ink-3);
}
.lab__val { color: var(--ink); font-weight: 500; font-variant-numeric: tabular-nums; }

.lab__input { width: 100%; accent-color: var(--signal); font-family: inherit; }
.lab__textarea, input.lab__input[type="text"], .lab__select {
  background: var(--ground); color: var(--ink);
  border: var(--hair) solid var(--rule); border-radius: 5px;
  padding: 7px 9px; font-family: var(--mono); font-size: 12.5px; line-height: 1.5;
}
.lab__textarea { resize: vertical; }
.lab__input:focus-visible { outline: 2px solid var(--signal); outline-offset: 1px; }
.lab__btn {
  font-family: var(--mono); font-size: 11px; letter-spacing: .08em;
  text-transform: uppercase; cursor: pointer;
  background: var(--signal-wash); color: var(--signal);
  border: var(--hair) solid var(--signal); border-radius: 5px; padding: 7px 14px;
}
.lab__btn:hover { background: var(--signal); color: var(--panel); }

.lab__out { margin-top: 18px; padding-top: 15px; border-top: var(--hair) solid var(--rule-2); }
.lab__msg { font-size: 13.5px; line-height: 1.5; color: var(--ink-3); margin: 12px 0 0; max-width: 78ch; }
.lab__msg.is-warn { color: var(--caution); }
.lab__msg.is-bad  { color: var(--bad); }

.lab__big { display: flex; align-items: baseline; gap: 10px; flex-wrap: wrap; margin-bottom: 12px; }
.lab__big b {
  font-family: var(--display); font-size: 30px; line-height: 1; color: var(--signal);
  font-variant-numeric: tabular-nums;
}
.lab__big span { font-size: 13.5px; color: var(--ink-3); }
.lab__big.is-ok b { color: var(--good); }
.lab__big.is-warn b { color: var(--caution); }
.lab__big.is-bad b { color: var(--bad); }

.lab__row {
  display: flex; justify-content: space-between; gap: 14px; padding: 4px 0;
  font-size: 13.5px; color: var(--ink-2); border-bottom: var(--hair) solid var(--rule-2);
}
.lab__row:last-child { border-bottom: 0; }
.lab__row b { font-family: var(--mono); color: var(--ink); font-variant-numeric: tabular-nums; }
.lab__row.is-ok b { color: var(--good); }
.lab__row.is-warn b { color: var(--caution); }
.lab__row.is-bad b { color: var(--bad); }

.lab__bars { display: grid; gap: 4px; margin: 10px 0 14px; }
.lab__brow {
  display: grid; grid-template-columns: minmax(64px, 96px) 1fr minmax(52px, auto);
  align-items: center; gap: 10px; font-size: 13px;
}
.lab__brow > span { font-family: var(--mono); color: var(--ink-3); overflow: hidden; text-overflow: ellipsis; }
.lab__brow > b { font-family: var(--mono); text-align: right; font-variant-numeric: tabular-nums; }
.lab__btrack { background: var(--panel-2); border-radius: 3px; height: 11px; overflow: hidden; }
.lab__btrack i { display: block; height: 100%; background: var(--signal); }
.lab__btrack i.is-ok { background: var(--good); }
.lab__btrack i.is-warn { background: var(--caution); }
.lab__btrack i.is-bad { background: var(--bad); }

.lab__chips { display: flex; flex-wrap: wrap; gap: 4px; margin: 10px 0 14px; }
.lab__chip {
  font-family: var(--mono); font-size: 12px; font-style: normal;
  padding: 3px 7px; border-radius: 4px;
  background: var(--panel-2); border: var(--hair) solid var(--rule-2); color: var(--ink);
}
.lab__chip.is-ok   { background: var(--good-wash); border-color: var(--good); color: var(--good); }
.lab__chip.is-warn { background: var(--caution-wash); border-color: var(--caution); color: var(--caution); }
.lab__chip.is-bad  { background: var(--bad-wash); border-color: var(--bad); color: var(--bad); }

.lab__tw { overflow-x: auto; margin: 12px 0 0; }
.lab__table { border-collapse: collapse; width: 100%; font-size: 13px; }
.lab__table th {
  font-family: var(--mono); font-size: 10px; letter-spacing: .08em; text-transform: uppercase;
  color: var(--ink-3); text-align: left; padding: 0 10px 6px 0;
  border-bottom: var(--hair) solid var(--rule);
}
.lab__table td {
  padding: 5px 10px 5px 0; border-bottom: var(--hair) solid var(--rule-2);
  font-variant-numeric: tabular-nums;
}
.lab__table tr:last-child td { border-bottom: 0; }

/* attention heat grid */
.lab__grid { display: grid; gap: 2px; margin: 12px 0 14px; font-family: var(--mono); font-size: 10.5px; }
.lab__gh { color: var(--ink-3); font-size: 9.5px; text-align: center; padding-bottom: 2px;
  overflow: hidden; text-overflow: ellipsis; }
.lab__gl { color: var(--ink-3); font-size: 9.5px; text-align: right; padding-right: 6px; line-height: 26px; }
.lab__cell {
  height: 26px; display: flex; align-items: center; justify-content: center; border-radius: 2px;
  background: color-mix(in srgb, var(--signal) calc(var(--w) * 100%), var(--panel-2));
}
.lab__cell span { color: var(--ink); mix-blend-mode: normal; font-size: 9.5px; }
.lab__cell.is-masked { background: repeating-linear-gradient(45deg,
  var(--panel-2) 0 3px, transparent 3px 6px); }

@media print { .lab { display: none; } }

/* ======================================================================
   SIMULATIONS (sims.js) — a mechanism played forward in time.
   Shares the lab's frame; adds scenario tabs, a stage, and a transport.
   ====================================================================== */
.sim {
  border: var(--hair) solid var(--rule);
  border-radius: 10px;
  background: var(--panel);
  padding: 18px 20px 16px;
  margin: 0 0 26px;
}
.sim:focus-visible { outline: 2px solid var(--signal); outline-offset: 2px; }
.sim__fallback { margin: 0; font-size: 14px; color: var(--ink-3); }
.sim--failed { display: none; }

.sim__head { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.sim__tag {
  font: 600 10.5px/1 var(--mono);
  letter-spacing: .09em; text-transform: uppercase;
  color: var(--signal); background: var(--signal-wash);
  border: var(--hair) solid var(--signal); border-radius: 999px;
  padding: 4px 8px; flex: none;
}
.sim__title { font-weight: 600; font-size: 15.5px; }
.sim__note {
  margin: 10px 0 0; font-size: 13.5px; line-height: 1.55;
  color: var(--ink-2); max-width: 78ch;
}

/* ---- scenario tabs ---- */
.sim__tabs { display: flex; align-items: center; gap: 6px; margin-top: 16px; flex-wrap: wrap; }
.sim__tab {
  font: 500 12.5px/1 var(--sans);
  color: var(--ink-2); background: transparent;
  border: var(--hair) solid var(--rule); border-radius: 6px;
  padding: 7px 12px; cursor: pointer;
}
.sim__tab:hover { color: var(--ink); border-color: var(--ink-3); }
.sim__tab.is-on {
  color: var(--panel); background: var(--signal); border-color: var(--signal);
}
.sim__reset {
  font: 400 15px/1 var(--sans); color: var(--ink-3);
  background: transparent; border: var(--hair) solid transparent; border-radius: 6px;
  padding: 6px 9px; cursor: pointer; margin-left: 2px;
}
.sim__reset:hover { color: var(--ink); border-color: var(--rule); }

/* ---- stage ---- */
.sim__stage { margin-top: 16px; min-height: 40px; min-width: 0; }

.sim__flow {
  display: flex; align-items: center; gap: 12px;
  /* wrap rather than scroll: a card pushed off the right edge is a card the
     reader never sees, and several sims put three wide nodes in one flow */
  flex-wrap: wrap; overflow-x: auto; padding-bottom: 4px;
}
.sim__flow > * { flex: 0 1 auto; min-width: 0; max-width: 100%; }
.sim__arrow { color: var(--ink-3); font-size: 17px; flex: none; }
.sim__stack { display: grid; gap: 10px; min-width: 0; }
.sim__stack > * { min-width: 0; max-width: 100%; }
.sim__cols { display: flex; gap: 14px; flex-wrap: wrap; align-items: flex-start; }
.sim__cols > * { flex: 1 1 200px; min-width: 0; }

/* ---- node card ---- */
.sim__node {
  border: 1.5px solid var(--rule); border-radius: 9px;
  background: var(--panel-2); padding: 12px 14px;
  min-width: min(230px, 100%); max-width: 100%; overflow-x: auto;
}
.sim__node--ok   { border-color: var(--good); }
.sim__node--warn { border-color: var(--caution); }
.sim__node--bad  { border-color: var(--bad); }
.sim__node--idle { border-color: var(--rule); opacity: .58; }
.sim__nhead { display: flex; align-items: center; justify-content: space-between; gap: 10px; }
.sim__ntitle { font: 600 13.5px/1.3 var(--sans); color: var(--ink); }
.sim__status {
  font: 600 9.5px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase;
  border-radius: 4px; padding: 4px 6px; flex: none;
  color: var(--ink-3); background: var(--panel); border: var(--hair) solid var(--rule);
}
.sim__status--ok   { color: var(--good);    background: var(--good-wash);    border-color: var(--good); }
.sim__status--warn { color: var(--caution); background: var(--caution-wash); border-color: var(--caution); }
.sim__status--bad  { color: var(--bad);     background: var(--bad-wash);     border-color: var(--bad); }
.sim__nmeta {
  display: flex; align-items: center; gap: 8px; flex-wrap: wrap; margin-top: 8px;
  font: 400 11px/1.4 var(--mono); color: var(--ink-3);
}
.sim__badge {
  font: 500 11px/1 var(--mono); color: var(--signal);
  background: var(--signal-wash); border-radius: 4px; padding: 4px 7px;
}
.sim__gauges { display: grid; gap: 9px; margin-top: 12px; }
.sim__gauge { display: grid; gap: 4px; }
.sim__glabel {
  display: flex; justify-content: space-between; gap: 10px;
  font: 400 11.5px/1 var(--mono); color: var(--ink-3);
}
.sim__glabel b { color: var(--ink-2); font-variant-numeric: tabular-nums; }
.sim__gtrack { background: var(--panel); border-radius: 3px; height: 7px; overflow: hidden; }
.sim__gtrack i { display: block; height: 100%; background: var(--good); transition: width .35s ease; }
.sim__gauge--warn .sim__gtrack i { background: var(--caution); }
.sim__gauge--bad  .sim__gtrack i { background: var(--bad); }
.sim__gauge--idle .sim__gtrack i { background: var(--ink-3); }
.sim__nrows { margin-top: 11px; border-top: var(--hair) solid var(--rule); padding-top: 9px; display: grid; gap: 6px; }
.sim__nrow {
  display: flex; justify-content: space-between; gap: 10px;
  font: 400 11.5px/1.4 var(--mono); color: var(--ink-3);
}
.sim__nrow b { color: var(--ink-2); font-variant-numeric: tabular-nums; }
.sim__nrow--ok b   { color: var(--good); }
.sim__nrow--warn b { color: var(--caution); }
.sim__nrow--bad b  { color: var(--bad); }
.sim__nbody { margin-top: 11px; }

/* ---- stat tile ---- */
.sim__stat {
  border: var(--hair) solid var(--rule); border-radius: 7px;
  background: var(--panel-2); padding: 10px 13px; display: grid; gap: 3px; min-width: min(112px, 100%);
}
.sim__stat--ok   { background: var(--good-wash);    border-color: var(--good); }
.sim__stat--warn { background: var(--caution-wash); border-color: var(--caution); }
.sim__stat--bad  { background: var(--bad-wash);     border-color: var(--bad); }
.sim__slabel {
  font: 600 9.5px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; color: var(--ink-3);
}
.sim__sval { font: 600 15px/1.2 var(--mono); color: var(--ink); font-variant-numeric: tabular-nums; }
.sim__stat--ok .sim__sval   { color: var(--good); }
.sim__stat--warn .sim__sval { color: var(--caution); }
.sim__stat--bad .sim__sval  { color: var(--bad); }
.sim__ssub { font: 400 10.5px/1.3 var(--mono); color: var(--ink-3); }

/* ---- big figure ---- */
.sim__big { display: grid; gap: 2px; min-width: 96px; }
.sim__big b {
  font: 600 29px/1 var(--display); color: var(--ink);
  font-variant-numeric: tabular-nums; letter-spacing: .01em;
}
.sim__big span {
  font: 600 9.5px/1.3 var(--mono); letter-spacing: .08em;
  text-transform: uppercase; color: var(--ink-3);
}
.sim__big--ok b   { color: var(--good); }
.sim__big--warn b { color: var(--caution); }
.sim__big--bad b  { color: var(--bad); }

/* ---- cell grid ---- */
.sim__clabel {
  font: 600 9.5px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase;
  color: var(--ink-3); margin-bottom: 7px;
}
.sim__cells { display: flex; flex-wrap: wrap; gap: 4px; }
.sim__cell {
  font: 500 10.5px/1 var(--mono);
  min-width: 26px; height: 26px; padding: 0 5px;
  display: inline-flex; align-items: center; justify-content: center;
  border: var(--hair) solid var(--rule); border-radius: 4px;
  background: var(--panel-2); color: var(--ink-3);
  transition: background .25s ease, border-color .25s ease, color .25s ease;
}
.sim__cells--dense .sim__cell { min-width: 15px; height: 15px; padding: 0 2px; font-size: 9px; border-radius: 3px; }
.sim__cell--ok   { background: var(--good-wash);    border-color: var(--good);    color: var(--good); }
.sim__cell--warn { background: var(--caution-wash); border-color: var(--caution); color: var(--caution); }
.sim__cell--bad  { background: var(--bad-wash);     border-color: var(--bad);     color: var(--bad); }
.sim__cell--idle { opacity: .4; }

/* ---- timeline lane ---- */
.sim__lane { display: flex; align-items: center; gap: 10px; margin-bottom: 5px; min-width: 0; }
.sim__lname {
  font: 500 11px/1 var(--mono); color: var(--ink-3);
  flex: none; width: 74px; text-align: right;
  overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.sim__lcells { display: flex; gap: 3px; overflow-x: auto; padding-bottom: 2px; flex: 1; min-width: 0; }
.sim__lcell {
  font: 500 9.5px/1 var(--mono);
  min-width: 30px; height: 21px; flex: none;
  display: inline-flex; align-items: center; justify-content: center;
  border: var(--hair) solid var(--rule); border-radius: 3px;
  background: var(--panel-2); color: var(--ink-3);
  transition: background .25s ease, border-color .25s ease;
}
.sim__lcell--ok   { background: var(--good-wash);    border-color: var(--good);    color: var(--good); }
.sim__lcell--warn { background: var(--caution-wash); border-color: var(--caution); color: var(--caution); }
.sim__lcell--bad  { background: var(--bad-wash);     border-color: var(--bad);     color: var(--bad); }
.sim__lcell--idle { opacity: .32; }

/* ---- load particles ---- */
.sim__dots {
  position: relative; width: 106px; height: 58px;
  border: var(--hair) solid var(--rule); border-radius: 7px;
  background: var(--panel-2); overflow: hidden;
}
.sim__dots i {
  position: absolute; width: 6px; height: 6px; border-radius: 50%;
  background: var(--signal); transform: translate(-50%, -50%);
}
.sim__dots--warn i { background: var(--caution); }
.sim__dots--bad i  { background: var(--bad); }

/* ---- bar ---- */
.sim__bar { display: flex; align-items: center; gap: 10px; font: 400 11.5px/1 var(--mono); }
.sim__blabel { color: var(--ink-3); flex: 0 1 92px; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.sim__btrack { flex: 1; background: var(--panel-2); border-radius: 3px; height: 9px; overflow: hidden; min-width: 60px; }
.sim__btrack i { display: block; height: 100%; background: var(--signal); transition: width .35s ease; }
.sim__bar--ok .sim__btrack i   { background: var(--good); }
.sim__bar--warn .sim__btrack i { background: var(--caution); }
.sim__bar--bad .sim__btrack i  { background: var(--bad); }
.sim__bar b { color: var(--ink-2); font-variant-numeric: tabular-nums; flex: none; min-width: 42px; text-align: right; }

/* ---- pills / rows / table / mono ---- */
.sim__pills { display: flex; flex-wrap: wrap; gap: 5px; }
.sim__pill {
  font: 500 11px/1 var(--mono); border-radius: 999px; padding: 5px 9px;
  border: var(--hair) solid var(--rule); background: var(--panel-2); color: var(--ink-3);
}
.sim__pill--ok   { color: var(--good);    background: var(--good-wash);    border-color: var(--good); }
.sim__pill--warn { color: var(--caution); background: var(--caution-wash); border-color: var(--caution); }
.sim__pill--bad  { color: var(--bad);     background: var(--bad-wash);     border-color: var(--bad); }
.sim__row {
  display: flex; justify-content: space-between; gap: 12px;
  padding: 6px 0; border-bottom: var(--hair) solid var(--rule-2);
  font-size: 13px; color: var(--ink-2);
}
.sim__row:last-child { border-bottom: 0; }
.sim__row b { font-family: var(--mono); color: var(--ink); font-variant-numeric: tabular-nums; }
.sim__row--ok b   { color: var(--good); }
.sim__row--warn b { color: var(--caution); }
.sim__row--bad b  { color: var(--bad); }
.sim__tablewrap { overflow-x: auto; max-width: 100%; min-width: 0; }
.sim__table { width: 100%; border-collapse: collapse; font-size: 12.5px; }
.sim__table th, .sim__table td {
  text-align: left; padding: 6px 9px; border-bottom: var(--hair) solid var(--rule-2);
}
.sim__table th { font: 600 10px/1 var(--mono); letter-spacing: .07em; text-transform: uppercase; color: var(--ink-3); }
.sim__table td { font-family: var(--mono); color: var(--ink-2); font-variant-numeric: tabular-nums; }
.sim__mono {
  font: 400 12px/1.6 var(--mono); color: var(--ink-2);
  background: var(--panel-2); border: var(--hair) solid var(--rule);
  border-radius: 6px; padding: 9px 12px; white-space: pre-wrap; overflow-x: auto;
}
.sim__mono--ok   { color: var(--good);    border-color: var(--good); }
.sim__mono--warn { color: var(--caution); border-color: var(--caution); }
.sim__mono--bad  { color: var(--bad);     border-color: var(--bad); }
.sim__msg { font-size: 13px; line-height: 1.55; color: var(--ink-3); margin: 12px 0 0; max-width: 78ch; }
.sim__msg--ok   { color: var(--good); }
.sim__msg--warn { color: var(--caution); }
.sim__msg--bad  { color: var(--bad); }

/* ---- caption + transport ---- */
.sim__deck {
  margin-top: 16px; border: var(--hair) solid var(--rule); border-radius: 8px;
  background: var(--panel-2); overflow: hidden;
}
.sim__caption {
  margin: 0; padding: 12px 14px; font-size: 13.5px; line-height: 1.5;
  color: var(--ink-2); min-height: 20px;
}
.sim__caption--ok   { color: var(--good); }
.sim__caption--warn { color: var(--caution); }
.sim__caption--bad  { color: var(--bad); }
.sim__transport {
  display: flex; align-items: center; gap: 8px;
  padding: 10px 12px; border-top: var(--hair) solid var(--rule);
}
.sim__ctl {
  font: 400 14px/1 var(--sans); color: var(--ink-2);
  background: var(--panel); border: var(--hair) solid var(--rule); border-radius: 6px;
  min-width: 34px; height: 32px; padding: 0 9px; cursor: pointer; flex: none;
  display: inline-flex; align-items: center; justify-content: center;
}
.sim__ctl:hover:not(:disabled) { color: var(--ink); border-color: var(--ink-3); }
.sim__ctl:disabled { opacity: .35; cursor: default; }
.sim__ctl:focus-visible { outline: 2px solid var(--signal); outline-offset: 1px; }
.sim__play { color: var(--signal); border-color: var(--signal); }
.sim__play:hover:not(:disabled) { background: var(--signal); color: var(--panel); }
.sim__speed, .sim__fs { font: 500 11.5px/1 var(--mono); }
.sim__scrub { flex: 1; min-width: 60px; accent-color: var(--signal); cursor: pointer; }
.sim__count {
  font: 500 11.5px/1 var(--mono); color: var(--ink-3);
  font-variant-numeric: tabular-nums; flex: none; min-width: 44px; text-align: center;
}

/* ---- fullscreen ---- */
.sim:fullscreen {
  background: var(--ground); overflow-y: auto;
  padding: 32px clamp(20px, 6vw, 80px); border-radius: 0; margin: 0;
}
.sim:fullscreen .sim__stage { min-height: 44vh; display: flex; align-items: center; }
.sim:fullscreen .sim__stage > * { width: 100%; }

/* ---- reduced motion ---- */
.sim--still .sim__gtrack i,
.sim--still .sim__btrack i,
.sim--still .sim__cell,
.sim--still .sim__lcell { transition: none; }

@media (max-width: 620px) {
  .sim { padding: 15px 14px 13px; }
  .sim__lname { width: 54px; }
  .sim__count { min-width: 38px; }
}
.sim__dlabel { font: 600 9px/1.3 var(--mono); letter-spacing: .07em; text-transform: uppercase; color: var(--ink-3); margin-top: 6px; }