/* ============================================================================
   BMM — The Mathematics. Interactive developer documentation.
   Tokenized dark + light themes (toggle in app.js, persisted to localStorage),
   scroll-reveal, a reading-progress bar, and motion that respects
   prefers-reduced-motion. KaTeX is vendored under vendor/katex.
   ========================================================================== */

/* ----- design tokens : DARK (default) ------------------------------------- */
:root {
  --bg: #0b0e14;
  --panel: #11161f;
  --panel-2: #161c28;
  --edge: #232c3b;
  --edge-soft: #1b2230;
  --fg: #e6ebf2;
  --strong: #ffffff;
  --muted: #8b97a8;
  --faint: #5b6678;
  --accent: #5b9dff;
  --accent-soft: #16233b;
  --buy: #34d399;
  --buy-soft: #0f2a23;
  --sell: #f87171;
  --sell-soft: #2a1518;
  --warn: #fbbf24;
  --code-bg: #0d1118;
  --code-fg: #cdd6e4;
  --toc-bg: rgba(13, 17, 24, 0.62);
  --shadow: 0 18px 40px -22px rgba(0, 0, 0, 0.8);
  --glow-a: rgba(91, 157, 255, 0.08);
  --glow-b: rgba(52, 211, 153, 0.05);
  /* syntax */
  --sx-cmt: var(--faint);
  --sx-kw: #c792ea;
  --sx-fn: #82aaff;
  --sx-str: #c3e88d;
  --sx-num: #f78c6c;
  /* translucent plot tints (theme-neutral, read by canvas) */
  --tint-accent: rgba(91, 157, 255, 0.16);
  --tint-buy: rgba(52, 211, 153, 0.12);
  --tint-buy-strong: rgba(52, 211, 153, 0.32);

  --radius: 12px;
  --maxw: 1180px;
  --sidebar: 270px;
  --mono: ui-monospace, "SF Mono", "JetBrains Mono", "Fira Code", Menlo, Consolas, monospace;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, Inter, sans-serif;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  color-scheme: dark;
}

/* ----- design tokens : LIGHT ---------------------------------------------- */
:root[data-theme="light"] {
  --bg: #f5f8fd;
  --panel: #ffffff;
  --panel-2: #eef2f9;
  --edge: #d9e1ee;
  --edge-soft: #e7edf6;
  --fg: #1b2433;
  --strong: #0a111d;
  --muted: #54607a;
  --faint: #8b97ab;
  --accent: #2f6df0;
  --accent-soft: #e3edff;
  --buy: #0a9c69;
  --buy-soft: #e0f6ee;
  --sell: #e2484d;
  --sell-soft: #fdeaea;
  --warn: #b67d09;
  --code-bg: #f1f5fb;
  --code-fg: #33415a;
  --toc-bg: rgba(245, 248, 253, 0.72);
  --shadow: 0 18px 38px -24px rgba(36, 60, 110, 0.4);
  --glow-a: rgba(47, 109, 240, 0.08);
  --glow-b: rgba(10, 156, 105, 0.06);
  --sx-cmt: #8b97ab;
  --sx-kw: #9333ea;
  --sx-fn: #2563eb;
  --sx-str: #15803d;
  --sx-num: #c2410c;
  --tint-accent: rgba(47, 109, 240, 0.16);
  --tint-buy: rgba(10, 156, 105, 0.14);
  --tint-buy-strong: rgba(10, 156, 105, 0.3);
  color-scheme: light;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 1.5rem;
}

body {
  margin: 0;
  background: radial-gradient(1200px 600px at 80% -10%, var(--glow-a), transparent 60%),
    radial-gradient(900px 500px at -10% 10%, var(--glow-b), transparent 55%), var(--bg);
  background-attachment: fixed;
  color: var(--fg);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.4s var(--ease), color 0.3s var(--ease);
}

/* ----- reading-progress bar ----------------------------------------------- */
.progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0%;
  z-index: 60;
  background: linear-gradient(90deg, var(--accent), var(--buy));
  box-shadow: 0 0 12px var(--accent);
  transition: width 0.1s linear;
}

/* ----- theme toggle ------------------------------------------------------- */
.theme-toggle {
  position: fixed;
  top: 0.9rem;
  right: 1rem;
  z-index: 61;
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.4rem 0.7rem 0.4rem 0.6rem;
  border: 1px solid var(--edge);
  border-radius: 999px;
  background: var(--panel);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.74rem;
  cursor: pointer;
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
  transition: transform 0.2s var(--ease), border-color 0.2s, color 0.2s, background 0.3s;
}
.theme-toggle:hover {
  color: var(--fg);
  border-color: var(--accent);
  transform: translateY(-1px);
}
.theme-toggle:active {
  transform: translateY(0) scale(0.97);
}
.theme-toggle .glyph {
  display: inline-grid;
  place-items: center;
  width: 18px;
  height: 18px;
  font-size: 0.95rem;
  transition: transform 0.5s var(--ease);
}
:root[data-theme="light"] .theme-toggle .glyph {
  transform: rotate(180deg);
}
.theme-toggle .lbl {
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
/* show the glyph for the theme you'll switch TO */
.theme-toggle .to-light,
:root[data-theme="light"] .theme-toggle .to-dark {
  display: none;
}
:root[data-theme="light"] .theme-toggle .to-light {
  display: inline;
}

/* ----- mode switch (trader / developer) ----------------------------------- */
.mode-switch {
  position: fixed;
  top: 0.9rem;
  left: 1rem;
  z-index: 61;
  display: inline-flex;
  gap: 0.2rem;
  padding: 0.22rem;
  border: 1px solid var(--edge);
  border-radius: 999px;
  background: var(--panel);
  box-shadow: var(--shadow);
  backdrop-filter: blur(8px);
}
.mode-switch .ms-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.32rem 0.8rem;
  border: none;
  border-radius: 999px;
  background: transparent;
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.03em;
  cursor: pointer;
  transition: color 0.18s, background 0.25s var(--ease);
}
.mode-switch .ms-btn .ms-i {
  font-size: 0.92rem;
}
.mode-switch .ms-btn:hover {
  color: var(--fg);
}
:root[data-mode="user"] .mode-switch .ms-btn[data-mode="user"],
:root[data-mode="dev"] .mode-switch .ms-btn[data-mode="dev"] {
  background: var(--accent-soft);
  color: var(--accent);
}

/* mode-gated content: show one set, hide the other (no-flash via <html> attr) */
:root[data-mode="user"] .mode-dev,
:root[data-mode="user"] .toc-dev,
:root[data-mode="user"] .brand-dev {
  display: none;
}
:root[data-mode="dev"] .mode-user,
:root[data-mode="dev"] .toc-user,
:root[data-mode="dev"] .brand-user {
  display: none;
}
.brand-user,
.brand-dev {
  display: inline;
}

/* ----- layout ------------------------------------------------------------- */
.layout {
  display: flex;
  gap: 0;
  max-width: var(--maxw);
  margin: 0 auto;
}

nav.toc {
  position: sticky;
  top: 0;
  align-self: flex-start;
  height: 100vh;
  width: var(--sidebar);
  flex: 0 0 var(--sidebar);
  overflow-y: auto;
  padding: 1.5rem 1rem 3rem 1.25rem;
  border-right: 1px solid var(--edge);
  background: var(--toc-bg);
  backdrop-filter: blur(6px);
  font-size: 0.86rem;
}
nav.toc .brand {
  font-weight: 700;
  font-size: 1.02rem;
  letter-spacing: -0.01em;
  margin-bottom: 0.25rem;
}
nav.toc .brand span {
  color: var(--accent);
}
nav.toc .sub {
  color: var(--muted);
  font-size: 0.74rem;
  margin-bottom: 1.25rem;
}
nav.toc a {
  position: relative;
  display: block;
  color: var(--muted);
  text-decoration: none;
  padding: 0.22rem 0.55rem;
  border-radius: 7px;
  border-left: 2px solid transparent;
  transition: color 0.16s, background 0.16s, border-color 0.16s, padding-left 0.16s var(--ease);
}
nav.toc a:hover {
  color: var(--fg);
  background: var(--panel-2);
  padding-left: 0.75rem;
}
nav.toc .group {
  margin-top: 0.85rem;
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--faint);
  padding-left: 0.55rem;
}
nav.toc a.active {
  color: var(--fg);
  background: var(--accent-soft);
  border-left-color: var(--accent);
}
nav.toc a.depth-2 {
  padding-left: 1.4rem;
  font-size: 0.8rem;
}

main {
  flex: 1 1 auto;
  min-width: 0;
  padding: 1.5rem clamp(1rem, 3vw, 3rem) 6rem;
}

/* ----- hero --------------------------------------------------------------- */
.hero {
  border: 1px solid var(--edge);
  border-radius: var(--radius);
  background: linear-gradient(160deg, var(--panel-2), var(--panel));
  padding: 2rem 2rem 1.75rem;
  margin-bottom: 2.5rem;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow);
}
.hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(600px 200px at 90% -40%, var(--glow-a), transparent 70%);
  pointer-events: none;
  animation: heroPulse 9s ease-in-out infinite;
}
.hero h1 {
  margin: 0 0 0.4rem;
  font-size: 2rem;
  letter-spacing: -0.02em;
}
.hero .grad {
  background: linear-gradient(95deg, var(--accent), var(--buy), var(--accent));
  background-size: 200% auto;
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  animation: shimmer 6s linear infinite;
}
.hero p {
  margin: 0.35rem 0 0;
  color: var(--muted);
  max-width: 70ch;
}
.hero .pills {
  margin-top: 1.1rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}
.pill {
  font-size: 0.72rem;
  font-family: var(--mono);
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  border: 1px solid var(--edge);
  background: var(--panel);
  color: var(--muted);
  transition: transform 0.18s var(--ease), color 0.18s, border-color 0.18s;
}
.pill:hover {
  transform: translateY(-2px);
  color: var(--fg);
  border-color: var(--accent);
}

/* ----- sections + scroll reveal ------------------------------------------- */
section {
  margin: 0 0 3rem;
  scroll-margin-top: 1.5rem;
}
section > h2 {
  font-size: 1.5rem;
  letter-spacing: -0.01em;
  margin: 0 0 0.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--edge);
}
.section-num {
  color: var(--accent);
  font-family: var(--mono);
  font-size: 0.95rem;
  margin-right: 0.5rem;
}
h3 {
  font-size: 1.12rem;
  margin: 2rem 0 0.5rem;
}
h4 {
  font-size: 0.98rem;
  margin: 1.4rem 0 0.4rem;
  color: var(--fg);
}
p {
  margin: 0.7rem 0;
}
.lead {
  color: var(--muted);
}
a.inline {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px dotted var(--accent);
}
a.inline:hover {
  border-bottom-style: solid;
}

ul,
ol {
  padding-left: 1.3rem;
}
li {
  margin: 0.3rem 0;
}
strong {
  color: var(--strong);
  font-weight: 650;
}

/* reveal-on-scroll: only active once JS adds .reveal-ready to <body> so the
   page is fully visible if scripts fail to load. */
body.reveal-ready section,
body.reveal-ready .hero {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.6s var(--ease), transform 0.6s var(--ease);
}
body.reveal-ready section.in,
body.reveal-ready .hero.in {
  opacity: 1;
  transform: none;
}

/* ----- callouts ----------------------------------------------------------- */
.note,
.idea,
.warn,
.dev,
.user,
.ex {
  border: 1px solid var(--edge);
  border-left-width: 3px;
  border-radius: 10px;
  padding: 0.85rem 1.05rem;
  margin: 1.1rem 0;
  background: var(--panel-2);
  font-size: 0.95rem;
}
.note {
  border-left-color: var(--accent);
}
.idea {
  border-left-color: var(--buy);
  background: var(--buy-soft);
}
.warn {
  border-left-color: var(--warn);
}
.dev {
  border-left-color: var(--accent);
  background: var(--accent-soft);
}
.user {
  border-left-color: var(--buy);
}
.ex {
  border-left-color: var(--warn);
  background: color-mix(in srgb, var(--warn) 7%, var(--panel-2));
}
.ex .katex {
  font-size: 1em;
}
.callout-title {
  font-weight: 700;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  display: block;
  margin-bottom: 0.3rem;
}
.note .callout-title {
  color: var(--accent);
}
.idea .callout-title {
  color: var(--buy);
}
.warn .callout-title {
  color: var(--warn);
}
.dev .callout-title {
  color: var(--accent);
}
.ex .callout-title {
  color: var(--warn);
}
.user .callout-title {
  color: var(--buy);
}

/* ----- evolution (Then → Now) cards --------------------------------------- */
/* A compact "what the logic was → what it is now → why we changed" card, used
   wherever a piece of the engine was redesigned (belief representation, the
   Gen·exact update, …). Old logic on the left (sell-red), new on the right
   (buy-green), the rationale underneath. Pure layout — no JS. */
.evo {
  border: 1px solid var(--edge);
  border-radius: 10px;
  margin: 1.1rem 0;
  background: var(--panel-2);
  overflow: hidden;
}
.evo > .callout-title {
  padding: 0.7rem 1.05rem 0;
  color: var(--muted);
}
.evo-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0;
}
.evo-then,
.evo-now {
  padding: 0.8rem 1.05rem;
  font-size: 0.93rem;
}
.evo-then {
  border-left: 3px solid var(--sell);
  background: color-mix(in srgb, var(--sell) 5%, var(--panel-2));
}
.evo-now {
  border-left: 3px solid var(--buy);
  background: color-mix(in srgb, var(--buy) 6%, var(--panel-2));
}
.evo-lab {
  font-weight: 700;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  display: block;
  margin-bottom: 0.35rem;
}
.evo-then .evo-lab {
  color: var(--sell);
}
.evo-now .evo-lab {
  color: var(--buy);
}
.evo-why {
  padding: 0.7rem 1.05rem 0.85rem;
  border-top: 1px solid var(--edge);
  font-size: 0.92rem;
}
.evo-why .evo-lab {
  color: var(--accent);
}
.evo p {
  margin: 0.4rem 0 0;
}
.evo p:first-of-type {
  margin-top: 0;
}
@media (max-width: 640px) {
  .evo-grid {
    grid-template-columns: 1fr;
  }
  .evo-then {
    border-bottom: 1px solid var(--edge);
  }
}

/* ----- code --------------------------------------------------------------- */
code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--code-bg);
  border: 1px solid var(--edge-soft);
  padding: 0.08em 0.36em;
  border-radius: 5px;
  color: var(--code-fg);
}
pre {
  background: var(--code-bg);
  border: 1px solid var(--edge);
  border-radius: 10px;
  padding: 0.95rem 1.1rem;
  overflow-x: auto;
  font-size: 0.84rem;
  line-height: 1.55;
  margin: 1rem 0;
}
pre code {
  background: none;
  border: none;
  padding: 0;
  color: var(--code-fg);
}
pre .cmt {
  color: var(--sx-cmt);
  font-style: italic;
}
pre .kw {
  color: var(--sx-kw);
}
pre .fn {
  color: var(--sx-fn);
}
pre .str {
  color: var(--sx-str);
}
pre .num {
  color: var(--sx-num);
}
.codecap {
  font-size: 0.72rem;
  color: var(--faint);
  font-family: var(--mono);
  margin: -0.6rem 0 1rem;
}
.codecap::before {
  content: "↳ ";
}

/* ----- KaTeX display tweaks ----------------------------------------------- */
.katex-display {
  margin: 1rem 0 !important;
  padding: 0.6rem 0.2rem;
  overflow-x: auto;
  overflow-y: hidden;
}
.katex {
  font-size: 1.04em;
}
.eqbox {
  border: 1px solid var(--edge);
  border-radius: 10px;
  background: var(--panel);
  padding: 0.4rem 1rem;
  margin: 1rem 0;
  transition: border-color 0.2s, box-shadow 0.2s, transform 0.2s var(--ease);
}
.eqbox:hover {
  border-color: var(--accent);
  box-shadow: var(--shadow);
}
.eqbox.named {
  display: flex;
  align-items: center;
  gap: 1rem;
}
.eqbox .eqlabel {
  margin-left: auto;
  font-family: var(--mono);
  font-size: 0.72rem;
  color: var(--faint);
  white-space: nowrap;
}

/* ----- tables ------------------------------------------------------------- */
.tablewrap {
  overflow-x: auto;
  margin: 1.1rem 0;
  border: 1px solid var(--edge);
  border-radius: 10px;
}
table {
  border-collapse: collapse;
  width: 100%;
  font-size: 0.88rem;
}
th,
td {
  text-align: left;
  padding: 0.55rem 0.8rem;
  border-bottom: 1px solid var(--edge-soft);
  vertical-align: top;
}
th {
  background: var(--panel-2);
  color: var(--muted);
  font-weight: 600;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  position: sticky;
  top: 0;
}
tr:last-child td {
  border-bottom: none;
}
tbody tr {
  transition: background 0.15s;
}
tbody tr:hover {
  background: var(--panel-2);
}
td code {
  white-space: nowrap;
}
.tnum {
  font-variant-numeric: tabular-nums;
  font-family: var(--mono);
}

/* ----- interactive widgets ------------------------------------------------ */
.viz {
  border: 1px solid var(--edge);
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  padding: 1.1rem 1.25rem 1.25rem;
  margin: 1.4rem 0;
  box-shadow: var(--shadow);
  transition: border-color 0.25s, box-shadow 0.25s;
}
.viz:hover {
  border-color: color-mix(in srgb, var(--accent) 50%, var(--edge));
}
.viz-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.75rem;
}
.viz-title {
  font-weight: 650;
  font-size: 0.95rem;
}
.viz-title .tag {
  font-family: var(--mono);
  font-size: 0.68rem;
  color: var(--accent);
  background: var(--accent-soft);
  border: 1px solid var(--edge);
  padding: 0.1rem 0.45rem;
  border-radius: 999px;
  margin-left: 0.5rem;
  vertical-align: middle;
}
.viz-title .tag::before {
  content: "●";
  margin-right: 0.3rem;
  font-size: 0.6em;
  vertical-align: middle;
  animation: blink 1.8s ease-in-out infinite;
}
.viz-hint {
  font-size: 0.78rem;
  color: var(--faint);
}
.viz-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 1.25rem;
  align-items: start;
}
@media (max-width: 820px) {
  .viz-grid {
    grid-template-columns: 1fr;
  }
  nav.toc {
    display: none;
  }
}
canvas {
  width: 100%;
  height: auto;
  display: block;
  background: var(--code-bg);
  border: 1px solid var(--edge);
  border-radius: 8px;
  transition: background 0.3s, border-color 0.3s;
}

.controls {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}
.control {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  transition: opacity 0.25s;
}
.control .row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.8rem;
}
.control label {
  color: var(--muted);
}
.control .val {
  font-family: var(--mono);
  color: var(--fg);
  font-size: 0.82rem;
}
input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  border-radius: 999px;
  background: var(--edge);
  outline: none;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: 2px solid var(--bg);
  box-shadow: 0 0 0 1px var(--accent);
  transition: transform 0.12s var(--ease), box-shadow 0.12s;
}
input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.25);
  box-shadow: 0 0 0 4px var(--accent-soft);
}
input[type="range"]::-webkit-slider-thumb:active {
  transform: scale(1.1);
}
input[type="range"]::-moz-range-thumb {
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: 2px solid var(--bg);
}

select,
.seg {
  background: var(--panel);
  color: var(--fg);
  border: 1px solid var(--edge);
  border-radius: 8px;
  padding: 0.35rem 0.5rem;
  font-size: 0.82rem;
  font-family: var(--sans);
  transition: background 0.15s, border-color 0.15s, color 0.15s, transform 0.1s var(--ease);
}
.seg-group {
  display: inline-flex;
  flex-wrap: wrap;
  gap: 0.3rem;
}
.seg {
  cursor: pointer;
  user-select: none;
}
.seg:hover {
  border-color: var(--accent);
  color: var(--fg);
}
.seg:active {
  transform: scale(0.95);
}
.seg.active {
  background: var(--accent-soft);
  border-color: var(--accent);
  color: var(--accent);
}

.readout {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 0.5rem 1rem;
  margin-top: 0.5rem;
  padding-top: 0.75rem;
  border-top: 1px solid var(--edge);
}
.readout .k {
  font-size: 0.72rem;
  color: var(--muted);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}
.readout .v {
  font-family: var(--mono);
  font-size: 1.05rem;
  font-weight: 600;
  animation: popIn 0.28s var(--ease);
}
.readout .v.buy {
  color: var(--buy);
}
.readout .v.sell {
  color: var(--sell);
}
.readout .v.accent {
  color: var(--accent);
}

/* spread bars (built once, widths transition) */
.bars .bar-row {
  margin: 0.35rem 0;
}
.bars .bar-head {
  display: flex;
  justify-content: space-between;
  font-size: 0.74rem;
  color: var(--muted);
}
.bars .bar-track {
  height: 9px;
  border-radius: 5px;
  background: var(--code-bg);
  overflow: hidden;
  margin-top: 2px;
}
.bars .bar-fill {
  height: 100%;
  width: 0%;
  border-radius: 5px;
  transition: width 0.45s var(--ease), background 0.3s;
}

.legend {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  font-size: 0.74rem;
  color: var(--muted);
  margin-top: 0.6rem;
}
.legend span {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}
.legend i {
  width: 14px;
  height: 3px;
  border-radius: 2px;
  display: inline-block;
}

/* ----- 3-up impact charts (§ price impact) -------------------------------- */
.impact-controls {
  margin-bottom: 1.1rem;
  max-width: 26rem;
}
.impact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.15rem;
}
.impact-grid.duo {
  grid-template-columns: 1fr 1fr;
}
@media (max-width: 980px) {
  .impact-grid,
  .impact-grid.duo {
    grid-template-columns: 1fr;
  }
}
.impact-cell {
  display: flex;
  flex-direction: column;
}
.impact-cell h4 {
  margin: 0 0 0.15rem;
  font-size: 0.86rem;
  font-weight: 650;
}
.impact-cell .cap {
  font-size: 0.74rem;
  color: var(--faint);
  margin: 0 0 0.55rem;
  min-height: 2.1em;
}
.impact-cell .readout {
  grid-template-columns: 1fr 1fr;
  margin-top: 0.55rem;
  padding-top: 0.55rem;
}
.impact-cell .readout .v {
  font-size: 0.92rem;
}
.buyx {
  color: var(--buy);
  font-weight: 600;
}
.sellx {
  color: var(--sell);
  font-weight: 600;
}

/* ----- misc --------------------------------------------------------------- */
.kbd {
  font-family: var(--mono);
  font-size: 0.78rem;
  background: var(--panel-2);
  border: 1px solid var(--edge);
  border-bottom-width: 2px;
  border-radius: 5px;
  padding: 0.05rem 0.35rem;
}
hr {
  border: none;
  border-top: 1px solid var(--edge);
  margin: 2.5rem 0;
}
.small {
  font-size: 0.82rem;
  color: var(--muted);
}
.anchor {
  color: var(--faint);
  text-decoration: none;
  opacity: 0;
  margin-left: 0.4rem;
  font-weight: 400;
  transition: opacity 0.15s;
}
h2:hover .anchor,
h3:hover .anchor {
  opacity: 1;
}
.footer {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--edge);
  color: var(--faint);
  font-size: 0.82rem;
}
details {
  border: 1px solid var(--edge);
  border-radius: 10px;
  padding: 0.5rem 0.9rem;
  margin: 1rem 0;
  background: var(--panel);
}
details summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--muted);
  transition: color 0.15s;
}
details summary:hover {
  color: var(--fg);
}
details[open] summary {
  margin-bottom: 0.5rem;
  color: var(--fg);
}
.sym {
  font-family: var(--mono);
  color: var(--accent);
}

/* ----- keyframes ---------------------------------------------------------- */
@keyframes shimmer {
  to {
    background-position: 200% center;
  }
}
@keyframes heroPulse {
  0%,
  100% {
    opacity: 0.55;
  }
  50% {
    opacity: 1;
  }
}
@keyframes blink {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.25;
  }
}
@keyframes popIn {
  from {
    opacity: 0;
    transform: translateY(3px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

/* ----- trader-mode content ------------------------------------------------ */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 0.85rem;
  margin: 1.2rem 0;
}
.card {
  border: 1px solid var(--edge);
  border-radius: 10px;
  background: linear-gradient(180deg, var(--panel-2), var(--panel));
  padding: 0.9rem 1rem;
  transition: transform 0.18s var(--ease), border-color 0.18s, box-shadow 0.18s;
}
.card:hover {
  transform: translateY(-2px);
  border-color: color-mix(in srgb, var(--buy) 45%, var(--edge));
  box-shadow: var(--shadow);
}
.card .card-h {
  font-weight: 650;
  font-size: 0.92rem;
  color: var(--strong);
  margin-bottom: 0.25rem;
}
.card .card-h::before {
  content: "›";
  color: var(--buy);
  font-weight: 700;
  margin-right: 0.4rem;
}
.card p {
  margin: 0;
  font-size: 0.88rem;
  color: var(--muted);
}

/* trader "place a trade" panel — plain-language readout, no formulas */
.u-trade-panel {
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
}
.u-trade-panel .u-row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  padding: 0.6rem 0.85rem;
  border: 1px solid var(--edge);
  border-radius: 9px;
  background: var(--panel);
}
.u-trade-panel .u-row .u-lab {
  font-size: 0.82rem;
  color: var(--muted);
}
.u-trade-panel .u-row .u-big {
  font-family: var(--mono);
  font-size: 1.15rem;
  font-weight: 650;
  animation: popIn 0.28s var(--ease);
}
.u-trade-panel .u-row .u-sub {
  font-size: 0.72rem;
  color: var(--faint);
  margin-left: 0.5rem;
}
.u-trade-panel .u-big.buy {
  color: var(--buy);
}
.u-trade-panel .u-big.sell {
  color: var(--sell);
}
.u-trade-panel .u-big.accent {
  color: var(--accent);
}
.u-move {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--mono);
  font-size: 1.05rem;
  font-weight: 600;
  padding: 0.6rem 0.85rem;
  border: 1px dashed var(--edge);
  border-radius: 9px;
  background: var(--panel-2);
}
.u-move .u-arrow {
  color: var(--accent);
  font-size: 1.2rem;
}

/* ----- interactive capacity sandbox --------------------------------------- */
details.cap-wrap {
  background: var(--panel-2);
}
details.cap-wrap > summary {
  font-size: 0.95rem;
  color: var(--accent);
}
details.cap-wrap[open] > summary {
  color: var(--accent);
}
.cap-sandbox {
  margin-top: 0.85rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.cap-intro {
  font-size: 0.86rem;
  color: var(--muted);
  margin: 0;
}
.cap-top {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--edge);
}
.cap-cashbox {
  font-size: 0.82rem;
  color: var(--muted);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}
.cap-cashbox input,
.cap-buy input {
  width: 6.5rem;
  font-family: var(--mono);
  font-size: 0.9rem;
  padding: 0.3rem 0.5rem;
  border: 1px solid var(--edge);
  border-radius: 7px;
  background: var(--code-bg);
  color: var(--fg);
}
.cap-market {
  font-size: 0.8rem;
  color: var(--faint);
}
.cap-market code {
  font-size: 0.92em;
}

.cap-status {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  font-weight: 650;
  font-size: 0.92rem;
  padding: 0.6rem 0.9rem;
  border-radius: 9px;
  border: 1px solid var(--edge);
}
.cap-status .dot {
  width: 0.6rem;
  height: 0.6rem;
  border-radius: 999px;
  background: currentColor;
  box-shadow: 0 0 0 3px color-mix(in srgb, currentColor 22%, transparent);
}
.cap-status.buy {
  color: var(--buy);
  background: var(--buy-soft);
  border-color: color-mix(in srgb, var(--buy) 40%, var(--edge));
}
.cap-status.sell {
  color: var(--sell);
  background: var(--sell-soft);
  border-color: color-mix(in srgb, var(--sell) 40%, var(--edge));
}
.cap-status.warn {
  color: var(--warn);
  background: color-mix(in srgb, var(--warn) 10%, var(--panel));
  border-color: color-mix(in srgb, var(--warn) 40%, var(--edge));
}

.cap-grid {
  display: grid;
  grid-template-columns: 1.15fr 1fr;
  gap: 1.1rem;
  align-items: start;
}
.cap-charts {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}
.cap-chart {
  margin: 0;
}
.cap-chart figcaption {
  font-size: 0.74rem;
  color: var(--muted);
  margin-bottom: 0.3rem;
}
.cap-stats {
  margin-top: 0;
  border-top: none;
}
@media (max-width: 820px) {
  .cap-grid,
  .cap-tables {
    grid-template-columns: 1fr;
  }
}

.cap-fixes {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}
.cap-fixes-head {
  font-size: 0.82rem;
  color: var(--muted);
}
.cap-fix-select {
  gap: 0.35rem;
}
.cap-fix-btn {
  font-size: 0.78rem;
  text-align: left;
}
.cap-fix-btn .lt {
  font-family: var(--mono);
  font-weight: 700;
  color: var(--accent);
  margin-right: 0.15rem;
}
.cap-fix-btn.star.active {
  border-color: var(--warn);
  color: var(--warn);
  background: color-mix(in srgb, var(--warn) 12%, var(--panel));
}
.cap-fix-btn.star.active .lt {
  color: var(--warn);
}
.cap-fix-btn.muted .lt {
  color: var(--faint);
}
.cap-fix-info {
  font-size: 0.84rem;
  color: var(--fg);
  background: var(--panel);
  border: 1px solid var(--edge);
  border-left: 3px solid var(--accent);
  border-radius: 8px;
  padding: 0.55rem 0.8rem;
}
.cap-fix-info p {
  margin: 0 0 0.4rem;
}
.cap-fix-info p:last-child {
  margin-bottom: 0;
}
.cap-fix-info .cap-approx {
  color: var(--warn);
  font-size: 0.8rem;
}
.cap-fix-info .cap-why {
  color: var(--muted);
  font-size: 0.82rem;
  font-style: italic;
}

.cap-buy {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.7rem;
  padding: 0.65rem 0.9rem;
  border: 1px solid var(--edge);
  border-radius: 9px;
  background: var(--panel);
}
.cap-buy label {
  font-size: 0.84rem;
  color: var(--muted);
}
.cap-btn {
  cursor: pointer;
  font-family: var(--sans);
  font-weight: 650;
  font-size: 0.84rem;
  padding: 0.4rem 1.1rem;
  border-radius: 8px;
  border: 1px solid color-mix(in srgb, var(--buy) 55%, var(--edge));
  background: var(--buy-soft);
  color: var(--buy);
  transition: transform 0.1s, background 0.15s;
}
.cap-btn:hover:not(:disabled) {
  background: color-mix(in srgb, var(--buy) 22%, var(--panel));
}
.cap-btn:active:not(:disabled) {
  transform: scale(0.96);
}
.cap-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}
.cap-buy-out {
  font-family: var(--mono);
  font-size: 0.82rem;
}
.cap-buy-out.buy {
  color: var(--buy);
}
.cap-buy-out.sell {
  color: var(--sell);
}
.cap-btn-sm {
  padding: 0.3rem 0.7rem;
  font-size: 0.78rem;
  border-color: color-mix(in srgb, var(--accent) 55%, var(--edge));
  background: var(--accent-soft);
  color: var(--accent);
}
.cap-btn-sm:hover:not(:disabled) {
  background: color-mix(in srgb, var(--accent) 20%, var(--panel));
}
.cap-cash-msg {
  font-size: 0.76rem;
  color: var(--buy);
  font-family: var(--mono);
}
.cap-buy {
  flex-direction: column;
  align-items: stretch;
  gap: 0.6rem;
}
.cap-buy-row {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem 0.7rem;
}
.cap-buy-lab {
  font-size: 0.8rem;
  color: var(--muted);
}
.cap-bt {
  font-size: 0.74rem;
  padding: 0.25rem 0.5rem;
}
.cap-knum {
  font-size: 0.8rem;
  color: var(--muted);
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
}
.cap-knum input {
  width: 4.2rem;
  font-family: var(--mono);
  font-size: 0.84rem;
  padding: 0.25rem 0.4rem;
  border: 1px solid var(--edge);
  border-radius: 6px;
  background: var(--code-bg);
  color: var(--fg);
}
.cap-buy-tip {
  margin: 0;
  font-size: 0.76rem;
  color: var(--faint);
}
.cap-ct {
  font-family: var(--mono);
  font-size: 0.92em;
  color: var(--muted);
}

.cap-tables {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.1rem;
}
.cap-tbl h4 {
  margin: 0 0 0.4rem;
  font-size: 0.88rem;
}
.cap-h-note {
  font-weight: 400;
  font-size: 0.74rem;
  color: var(--faint);
}
.cap-pay,
.cap-pos {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.8rem;
}
.cap-pay td,
.cap-pos td,
.cap-pos th {
  padding: 0.28rem 0.45rem;
  border-bottom: 1px solid var(--edge-soft);
}
.cap-pos th {
  text-align: left;
  color: var(--muted);
  font-weight: 600;
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}
.cap-pay .num,
.cap-pos .num {
  font-family: var(--mono);
  text-align: right;
}
.cap-pay .muted,
.cap-pos .muted {
  color: var(--faint);
  font-size: 0.92em;
}
.cap-pay .buy,
.cap-pos .buy {
  color: var(--buy);
}
.cap-pay .sell,
.cap-pos .sell {
  color: var(--sell);
}
.cap-pay .accent {
  color: var(--accent);
}
.cap-pay .srow td,
.cap-pos .trow td {
  border-top: 1px solid var(--edge);
  border-bottom: none;
  font-weight: 650;
}
.cap-pos .trow td {
  color: var(--muted);
}
.cap-forced {
  font-size: 0.78rem;
  color: var(--warn);
  margin: 0.4rem 0 0;
}
.cap-foot {
  color: var(--faint);
}
.cap-foot code {
  font-size: 0.92em;
}

/* ----- reduced motion ----------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
  body.reveal-ready section,
  body.reveal-ready .hero {
    opacity: 1;
    transform: none;
  }
}