/* ==========================================================================
   SeedSigner Independent Custody Guide — reading edition
   Visual direction: "evidence log" — a forensic dossier read on a device screen.
   ========================================================================== */

/* --- tokens -------------------------------------------------------------- */

:root {
  /* dark is the primary world: the device's own screen */
  --ground: #0a0d10;
  --ground-deep: #06080a;
  --panel: #12171c;
  --panel-2: #161c22;
  --rule: #222b33;
  --rule-soft: #1a2126;
  --text: #d6dde3;
  --text-strong: #f0f4f7;
  --muted: #8593a0;
  --faint: #707e8a;
  --signal: #ffa31a;
  --signal-dim: #b8741a;
  --signal-wash: rgba(255, 163, 26, 0.09);
  --selection: rgba(255, 163, 26, 0.24);

  --serif: Charter, "Iowan Old Style", "Palatino Linotype", Palatino, Georgia,
    "Times New Roman", serif;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, "DejaVu Sans Mono",
    "Liberation Mono", Consolas, monospace;

  --rail-w: 236px;
  --gutter: clamp(20px, 5vw, 64px);
  --measure: 63ch;
  --wide: 980px;

  /* type scale */
  --t-hero: clamp(2.5rem, 6.2vw, 4.6rem);
  --t-h2: clamp(1.85rem, 3.6vw, 2.9rem);
  --t-h3: clamp(1.24rem, 1.9vw, 1.55rem);
  --t-body: clamp(1.0625rem, 0.42vw + 1rem, 1.1875rem);
  --t-small: 0.8125rem;
  --t-micro: 0.6875rem;

  color-scheme: dark;
}

@media (prefers-color-scheme: light) {
  :root {
    --ground: #e9edf0;
    --ground-deep: #dde3e7;
    --panel: #f7f9fa;
    --panel-2: #fdfdfe;
    --rule: #c3cdd4;
    --rule-soft: #d6dee3;
    --text: #172026;
    --text-strong: #060b0f;
    --muted: #566470;
    --faint: #5c6a75;
    --signal: #a34d00;
    --signal-dim: #c2751f;
    --signal-wash: rgba(163, 77, 0, 0.07);
    --selection: rgba(163, 77, 0, 0.18);
    color-scheme: light;
  }
}

/* explicit toggle must beat the media query in both directions */
:root[data-theme="light"] {
  --ground: #e9edf0;
  --ground-deep: #dde3e7;
  --panel: #f7f9fa;
  --panel-2: #fdfdfe;
  --rule: #c3cdd4;
  --rule-soft: #d6dee3;
  --text: #172026;
  --text-strong: #060b0f;
  --muted: #566470;
  --faint: #5c6a75;
  --signal: #a34d00;
  --signal-dim: #c2751f;
  --signal-wash: rgba(163, 77, 0, 0.07);
  --selection: rgba(163, 77, 0, 0.18);
  color-scheme: light;
}

:root[data-theme="dark"] {
  --ground: #0a0d10;
  --ground-deep: #06080a;
  --panel: #12171c;
  --panel-2: #161c22;
  --rule: #222b33;
  --rule-soft: #1a2126;
  --text: #d6dde3;
  --text-strong: #f0f4f7;
  --muted: #8593a0;
  --faint: #707e8a;
  --signal: #ffa31a;
  --signal-dim: #b8741a;
  --signal-wash: rgba(255, 163, 26, 0.09);
  --selection: rgba(255, 163, 26, 0.24);
  color-scheme: dark;
}

/* --- reset & base -------------------------------------------------------- */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 24px;
  -webkit-text-size-adjust: 100%;
}

body {
  margin: 0;
  background: var(--ground);
  color: var(--text);
  font-family: var(--serif);
  font-size: var(--t-body);
  line-height: 1.62;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

::selection {
  background: var(--selection);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: inherit;
  text-decoration-color: var(--signal-dim);
  text-underline-offset: 0.18em;
  text-decoration-thickness: from-font;
}

a:hover {
  color: var(--signal);
}

:focus-visible {
  outline: 2px solid var(--signal);
  outline-offset: 3px;
}

h1,
h2,
h3,
h4 {
  font-weight: 600;
  text-wrap: balance;
  color: var(--text-strong);
  margin: 0;
}

.skip {
  position: fixed;
  left: 12px;
  top: 12px;
  z-index: 100;
  background: var(--panel);
  color: var(--text-strong);
  font-family: var(--mono);
  font-size: var(--t-small);
  padding: 10px 16px;
  border: 1px solid var(--signal);
  clip-path: inset(50%);
}

.skip:focus {
  clip-path: none;
}

/* --- furniture ----------------------------------------------------------- */

.eyebrow {
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
  margin: 0 0 1.1rem;
  display: flex;
  align-items: baseline;
  gap: 0.85em;
}

.eyebrow .num {
  color: var(--signal);
  font-variant-numeric: tabular-nums;
}

.eyebrow .num::after {
  content: " /";
  color: var(--faint);
}

.eyebrow .src {
  margin-left: auto;
  color: var(--faint);
  text-decoration: none;
  letter-spacing: 0.1em;
  white-space: nowrap;
}

.eyebrow .src:hover {
  color: var(--signal);
}

.label {
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

/* --- shell / rail -------------------------------------------------------- */

.progress {
  position: fixed;
  inset: 0 0 auto 0;
  height: 2px;
  z-index: 40;
  background: var(--rule-soft);
}

.progress i {
  display: block;
  height: 100%;
  width: 0;
  background: var(--signal);
}

.rail {
  position: fixed;
  left: 28px;
  top: 50%;
  transform: translateY(-50%);
  width: calc(var(--rail-w) - 56px);
  z-index: 30;
  font-family: var(--mono);
  font-size: var(--t-small);
}

.rail-head {
  font-size: var(--t-micro);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--faint);
  padding-bottom: 10px;
  margin-bottom: 10px;
  border-bottom: 1px solid var(--rule);
}

.rail ol {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 1px;
}

.rail ol a {
  display: grid;
  grid-template-columns: 1.4em 1fr;
  gap: 0.5em;
  padding: 4px 6px 4px 0;
  color: var(--faint);
  text-decoration: none;
  font-size: 0.78rem;
  line-height: 1.35;
  transition: color 0.18s ease;
}

.rail ol a span:first-child {
  font-variant-numeric: tabular-nums;
  color: var(--rule);
}

.rail ol a:hover {
  color: var(--text);
}

.rail ol a[aria-current="true"] {
  color: var(--signal);
}

.rail ol a[aria-current="true"] span:first-child {
  color: var(--signal);
}

.rail ol a[aria-current="true"] span:last-child::before {
  content: "› ";
  margin-left: -0.7em;
}

.rail-top {
  display: block;
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px solid var(--rule);
  color: var(--faint);
  text-decoration: none;
  font-size: 0.74rem;
  letter-spacing: 0.04em;
}

.rail-top:hover {
  color: var(--signal);
}

/* the collapsed bar: only used once the rail goes to the bottom of the screen */
.rail-toggle {
  display: none;
  width: 100%;
  align-items: center;
  justify-content: space-between;
  gap: 1em;
  background: none;
  border: 0;
  color: var(--text-strong);
  font-family: var(--mono);
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  padding: 14px var(--gutter);
  cursor: pointer;
  text-align: left;
}

.rail-toggle-mark {
  flex: none;
  width: 9px;
  height: 9px;
  border-right: 1.5px solid var(--signal);
  border-bottom: 1.5px solid var(--signal);
  transform: rotate(-135deg); /* points up: the sheet opens upward */
  transition: transform 0.2s ease;
}

.rail.open .rail-toggle-mark {
  transform: rotate(45deg); /* points down to dismiss */
}

.theme {
  position: fixed;
  bottom: 20px;
  right: 20px;
  z-index: 40;
  background: color-mix(in srgb, var(--panel) 88%, transparent);
  border: 1px solid var(--rule);
  color: var(--muted);
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 8px 12px;
  cursor: pointer;
  backdrop-filter: blur(6px);
}

.theme:hover {
  color: var(--signal);
  border-color: var(--signal-dim);
}

/* the contents sheet takes the bottom of the screen while it is open */
.nav-open .theme {
  opacity: 0;
  pointer-events: none;
}

/* --- column system ------------------------------------------------------- */

.col {
  width: min(100% - (var(--gutter) * 2), var(--wide));
  margin-inline: auto;
}

/* flex + gap rather than margins: no collapsing, no specificity fight with
   the element-level `p` reset below */
.prose {
  max-width: var(--measure);
  display: flex;
  flex-direction: column;
  gap: 1.3em;
}

.prose p {
  margin: 0;
}

.prose > h3.sub {
  margin-bottom: -0.45em;
}

.prose strong {
  color: var(--text-strong);
  font-weight: 600;
}

.lede {
  font-size: 1.16em;
  line-height: 1.55;
  color: var(--text-strong);
}

/* --- hero ---------------------------------------------------------------- */

.hero {
  position: relative;
  padding-block: clamp(56px, 9vh, 108px) clamp(56px, 8vh, 96px);
  border-bottom: 1px solid var(--rule);
  background: radial-gradient(
      120% 90% at 78% 12%,
      var(--signal-wash),
      transparent 62%
    ),
    var(--ground);
}

.hero-mark {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: clamp(24px, 4vw, 40px);
}

.hero-mark img {
  width: 150px;
}

.hero-mark p {
  margin: 0;
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.1em;
  line-height: 1.6;
  text-transform: uppercase;
  color: var(--faint);
  border-left: 1px solid var(--rule);
  padding-left: 14px;
}

.hero h1 {
  font-size: var(--t-hero);
  line-height: 1.02;
  letter-spacing: -0.02em;
  max-width: 22ch;
}

.hero-deck {
  max-width: 54ch;
  margin: 1.4rem 0 0;
  font-size: 1.1em;
  color: var(--text);
}

.hero-stats {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0 1.5rem;
  margin: 2rem 0 0;
  padding: 0;
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.hero-stats li b {
  color: var(--signal);
  font-weight: 400;
  font-variant-numeric: tabular-nums;
}

.hero-meta {
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--faint);
  margin: 1.6rem 0 0;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 2.2rem;
}

.btn {
  font-family: var(--mono);
  font-size: var(--t-small);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 13px 22px;
  text-decoration: none;
  border: 1px solid var(--rule);
  color: var(--text);
  transition: border-color 0.2s ease, color 0.2s ease, background 0.2s ease;
}

.btn:hover {
  border-color: var(--signal);
  color: var(--signal);
}

.btn-key {
  border-color: var(--signal);
  color: var(--ground);
  background: var(--signal);
}

.btn-key:hover {
  background: transparent;
  color: var(--signal);
}

/* --- chapters ------------------------------------------------------------ */

.chapter {
  padding-block: clamp(64px, 8.5vw, 128px);
  border-bottom: 1px solid var(--rule);
  position: relative;
}

.chapter:last-of-type {
  border-bottom: 0;
}

.chapter h2 {
  font-size: var(--t-h2);
  line-height: 1.08;
  letter-spacing: -0.015em;
  max-width: 26ch;
  margin-bottom: 1.6rem;
}

.chapter-alt {
  background: var(--panel);
}

.stack {
  display: flex;
  flex-direction: column;
  gap: clamp(28px, 3.5vw, 46px);
}

h3.sub {
  font-size: var(--t-h3);
  line-height: 1.2;
  letter-spacing: -0.01em;
  max-width: 30ch;
}

/* --- figures / exhibits -------------------------------------------------- */

.fig {
  margin: 0;
  max-width: var(--wide);
}

.fig-narrow {
  max-width: 620px;
}

.fig-slim {
  max-width: 400px;
}

.plate {
  position: relative;
  background: var(--panel-2);
  border: 1px solid var(--rule);
  padding: clamp(10px, 1.4vw, 18px);
}

.chapter-alt .plate {
  background: var(--ground);
}

/* amber crop marks — the QR registration corners */
.plate::before,
.plate::after {
  content: "";
  position: absolute;
  width: 16px;
  height: 16px;
  border-color: var(--signal);
  border-style: solid;
  pointer-events: none;
}

.plate::before {
  top: -1px;
  left: -1px;
  border-width: 1px 0 0 1px;
}

.plate::after {
  bottom: -1px;
  right: -1px;
  border-width: 0 1px 1px 0;
}

.fig figcaption {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.9em;
  margin-top: 0.85rem;
  font-family: var(--mono);
  font-size: var(--t-small);
  line-height: 1.55;
  color: var(--muted);
}

.fig figcaption .ex {
  color: var(--signal);
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.fig-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: clamp(18px, 2.4vw, 30px);
  align-items: start;
}

/* --- pull quote ---------------------------------------------------------- */

.pull {
  margin: 0;
  max-width: 34ch;
  border-top: 1px solid var(--signal);
  padding-top: 1.1rem;
}

.pull p {
  font-size: clamp(1.3rem, 2.2vw, 1.72rem);
  line-height: 1.28;
  letter-spacing: -0.012em;
  color: var(--text-strong);
  margin: 0;
  font-style: italic;
}

.pull cite {
  display: block;
  margin-top: 0.9rem;
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  font-style: normal;
}

.split {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
  gap: clamp(28px, 4vw, 64px);
  align-items: start;
}

/* --- device menu path ---------------------------------------------------- */

.path {
  font-family: var(--mono);
  font-size: 0.8rem;
  line-height: 2.1;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0 0.55em;
  margin: 0;
  padding: 12px 14px;
  background: var(--ground-deep);
  border: 1px solid var(--rule);
  color: var(--text-strong);
}

.chapter-alt .path {
  background: var(--ground);
}

.path b {
  font-weight: 400;
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--faint);
  margin-right: 0.4em;
}

.path span + span::before {
  content: "→";
  color: var(--signal);
  margin-right: 0.55em;
}

/* --- typed lists --------------------------------------------------------- */

.marks {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.7rem;
  max-width: var(--measure);
}

.marks li {
  position: relative;
  padding-left: 1.5em;
  line-height: 1.5;
}

.marks li::before {
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--mono);
  font-size: 0.8em;
  line-height: 1.85;
  color: var(--signal);
}

.marks-plus li::before {
  content: "+";
}

.marks-minus li::before {
  content: "−";
  color: var(--muted);
}

.marks-dot li::before {
  content: "·";
  font-size: 1.4em;
  line-height: 1.05;
}

.ledger {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: clamp(24px, 3vw, 44px);
}

.ledger > div > h3 {
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  padding-bottom: 10px;
  margin-bottom: 1.1rem;
  border-bottom: 1px solid var(--rule);
  font-weight: 400;
}

/* --- findings (objections + responses) ----------------------------------- */

.findings {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(330px, 1fr));
  gap: clamp(26px, 3vw, 40px);
  align-items: start;
}

.finding {
  border-top: 1px solid var(--rule);
  padding-top: 1.1rem;
}

.finding .verdict {
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--signal);
  margin: 0 0 0.7rem;
  display: flex;
  gap: 0.7em;
}

.finding .verdict i {
  color: var(--faint);
  font-style: normal;
  font-variant-numeric: tabular-nums;
}

.finding h3 {
  font-size: 1.05rem;
  line-height: 1.32;
  margin-bottom: 0.6rem;
}

.finding p:not(.verdict) {
  margin: 0;
  font-size: 0.98rem;
  line-height: 1.6;
  color: var(--text);
}

/* --- trust gradient ------------------------------------------------------ */

.gradient {
  border-top: 1px solid var(--rule);
  padding-top: 1.4rem;
}

.gradient-scale {
  display: flex;
  justify-content: space-between;
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  padding-bottom: 8px;
}

.gradient-bar {
  height: 3px;
  background: linear-gradient(
    to right,
    var(--signal),
    color-mix(in srgb, var(--signal) 20%, var(--rule))
  );
  margin-bottom: 1.8rem;
}

.methods {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: clamp(24px, 3vw, 38px);
}

.methods > div > .label {
  display: block;
  margin-bottom: 0.55rem;
}

.methods h3 {
  font-size: 1.08rem;
  margin-bottom: 0.6rem;
  line-height: 1.3;
}

.methods p {
  margin: 0;
  font-size: 0.98rem;
  line-height: 1.6;
}

/* --- epochs -------------------------------------------------------------- */

.epochs {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: clamp(24px, 3vw, 40px);
  counter-reset: epoch;
}

.epoch {
  border-top: 1px solid var(--rule);
  padding-top: 1.2rem;
}

.epoch-now {
  border-top-color: var(--signal);
}

.epoch .roman {
  font-family: var(--mono);
  font-size: 2.4rem;
  line-height: 1;
  color: var(--rule);
  display: block;
  margin-bottom: 0.9rem;
  font-variant-numeric: tabular-nums;
}

.epoch-now .roman {
  color: var(--signal);
}

.epoch h3 {
  font-size: 1.2rem;
  margin-bottom: 0.5rem;
}

.epoch .years {
  display: block;
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.12em;
  color: var(--muted);
  margin-bottom: 0.8rem;
}

.epoch p {
  margin: 0;
  font-size: 0.99rem;
  line-height: 1.58;
}

/* --- bill of materials --------------------------------------------------- */

.bom {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: clamp(24px, 3vw, 36px);
}

.part {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
}

.part-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1em;
  border-bottom: 1px solid var(--rule);
  padding-bottom: 8px;
}

.part-head h3 {
  font-size: 1.02rem;
  line-height: 1.3;
}

.part-head .price {
  font-family: var(--mono);
  font-size: var(--t-small);
  color: var(--signal);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

.part p {
  margin: 0;
  font-size: 0.97rem;
  line-height: 1.58;
}

/* --- walkthrough steps --------------------------------------------------- */

.step {
  display: grid;
  grid-template-columns: 3.4rem minmax(0, 1fr);
  gap: 0 clamp(14px, 2vw, 28px);
  border-top: 1px solid var(--rule);
  padding-top: 1.4rem;
}

.step > .step-n {
  font-family: var(--mono);
  font-size: 0.9rem;
  color: var(--signal);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.05em;
  padding-top: 0.35em;
}

.step-body {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  min-width: 0;
}

.step-body h3 {
  font-size: var(--t-h3);
  line-height: 1.22;
  max-width: 32ch;
}

.step-body > p {
  margin: 0;
  max-width: var(--measure);
}

/* --- callouts ------------------------------------------------------------ */

.note {
  max-width: 68ch;
  border-left: 2px solid var(--signal);
  padding: 2px 0 2px 18px;
  font-size: 0.99rem;
}

.note > .label {
  display: block;
  margin-bottom: 0.35rem;
  color: var(--signal);
}

.note p {
  margin: 0;
}

.note p + p {
  margin-top: 0.7em;
}

.note-edit {
  border-left-color: var(--faint);
}

.note-edit > .label {
  color: var(--faint);
}

.warn {
  max-width: 68ch;
  border: 1px solid var(--signal-dim);
  background: var(--signal-wash);
  padding: 16px 18px;
  font-size: 0.99rem;
}

.warn > .label {
  display: block;
  margin-bottom: 0.4rem;
  color: var(--signal);
}

.warn p {
  margin: 0;
}

/* --- disclosure ---------------------------------------------------------- */

details.aside {
  border: 1px solid var(--rule);
  background: var(--panel-2);
  max-width: 74ch;
}

.chapter-alt details.aside {
  background: var(--ground);
}

details.aside > summary {
  cursor: pointer;
  padding: 15px 18px;
  font-family: var(--mono);
  font-size: var(--t-small);
  letter-spacing: 0.04em;
  color: var(--text-strong);
  list-style: none;
  display: flex;
  gap: 0.8em;
  align-items: baseline;
}

details.aside > summary::-webkit-details-marker {
  display: none;
}

details.aside > summary::before {
  content: "+";
  color: var(--signal);
  font-size: 1.05em;
  line-height: 1;
}

details.aside[open] > summary::before {
  content: "−";
}

details.aside > summary:hover {
  color: var(--signal);
}

.aside-body {
  padding: 0 18px 18px;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  font-size: 0.99rem;
}

.aside-body p {
  margin: 0;
}

/* --- code / terminal ----------------------------------------------------- */

.term {
  border: 1px solid var(--rule);
  background: var(--ground-deep);
  max-width: 74ch;
  overflow-x: auto;
}

.chapter-alt .term {
  background: var(--ground);
}

.term table {
  border-collapse: collapse;
  width: 100%;
  font-family: var(--mono);
  font-size: 0.82rem;
}

.term th,
.term td {
  text-align: left;
  padding: 11px 16px;
  border-bottom: 1px solid var(--rule-soft);
  white-space: nowrap;
}

.term tr:last-child th,
.term tr:last-child td {
  border-bottom: 0;
}

.term th {
  font-weight: 400;
  color: var(--muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  font-size: var(--t-micro);
  width: 1%;
}

.term td {
  color: var(--signal);
}

code {
  font-family: var(--mono);
  font-size: 0.86em;
  color: var(--text-strong);
  background: var(--signal-wash);
  padding: 0.1em 0.35em;
}

/* --- variables grid ------------------------------------------------------ */

.vars {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.var {
  background: var(--ground);
  padding: clamp(20px, 2.2vw, 28px);
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}

.chapter-alt .var {
  background: var(--panel);
}

.var .label {
  color: var(--signal);
  font-variant-numeric: tabular-nums;
}

.var h3 {
  font-size: 1.05rem;
  line-height: 1.28;
}

.var p {
  margin: 0;
  font-size: 0.96rem;
  line-height: 1.58;
}

/* --- sources ------------------------------------------------------------- */

.sources {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: clamp(28px, 3.5vw, 48px);
  align-items: start;
}

.sources h3 {
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 400;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--rule);
  margin-bottom: 1rem;
}

.sources ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.sources li {
  font-size: 0.95rem;
  line-height: 1.45;
}

.sources li a {
  display: block;
  font-family: var(--mono);
  font-size: 0.78rem;
  color: var(--muted);
  word-break: break-all;
  margin-top: 0.15rem;
}

.sources li a:hover {
  color: var(--signal);
}

/* --- outro ------------------------------------------------------------- */

.outro {
  border-top: 1px solid var(--rule);
  background: var(--panel);
  padding-block: clamp(52px, 6.5vw, 92px);
}

.outro .label {
  display: block;
  color: var(--signal);
  margin: 0 0 1.1rem;
}

.outro h2 {
  font-size: var(--t-h2);
  line-height: 1.08;
  letter-spacing: -0.015em;
  max-width: 24ch;
  margin-bottom: 1.2rem;
}

.outro p:not(.label) {
  margin: 0;
  max-width: 58ch;
}

.outro-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 2.1rem;
}

/* --- footer -------------------------------------------------------------- */

footer {
  border-top: 1px solid var(--rule);
  background: var(--ground-deep);
  padding-block: clamp(48px, 6vw, 84px);
  font-size: 0.96rem;
}

.foot-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
}

.foot-grid h3 {
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 400;
  margin-bottom: 0.9rem;
}

.foot-grid p {
  margin: 0;
  color: var(--text);
  line-height: 1.6;
}

.foot-grid p + p {
  margin-top: 0.8em;
}

.foot-grid a {
  font-family: var(--mono);
  font-size: 0.8rem;
  overflow-wrap: anywhere;
}

.colophon {
  margin-top: clamp(36px, 4vw, 56px);
  padding-top: 1.4rem;
  border-top: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: var(--t-micro);
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--faint);
  line-height: 1.9;
}

/* --- reveal animation ---------------------------------------------------- */

.reveal {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.in {
  opacity: 1;
  transform: none;
}

/* --- responsive ---------------------------------------------------------- */

@media (min-width: 1180px) {
  body {
    padding-left: var(--rail-w);
  }
}

/* Below the rail breakpoint the contents become a collapsible bar pinned to the
   bottom of the screen — a 40-minute read needs navigation on a phone too. */
@media (max-width: 1179px) {
  .rail {
    left: 0;
    right: 0;
    top: auto;
    bottom: 0;
    width: auto;
    transform: none;
    background: color-mix(in srgb, var(--panel) 94%, transparent);
    backdrop-filter: blur(8px);
    border-top: 1px solid var(--rule);
    /* the bar sits at the bottom and the sheet stacks above it, so the visual
       order has to be reversed against the DOM order */
    display: flex;
    flex-direction: column;
  }

  .rail ol {
    order: 1;
  }

  .rail-top {
    order: 2;
  }

  .rail-toggle {
    order: 3;
  }

  .rail-head {
    display: none;
  }

  .rail-toggle {
    display: flex;
  }

  .rail.open .rail-toggle {
    border-top: 1px solid var(--rule-soft);
  }

  .rail ol,
  .rail-top {
    display: none;
  }

  .rail.open ol {
    display: flex;
    max-height: min(52vh, 420px);
    overflow-y: auto;
    padding: 10px var(--gutter);
    gap: 2px;
  }

  .rail.open .rail-top {
    display: block;
    margin: 0;
    padding: 12px var(--gutter);
    border-top: 1px solid var(--rule-soft);
  }

  .rail ol a {
    padding: 9px 0;
    font-size: 0.82rem;
  }

  /* keep the theme button clear of the bar */
  .theme {
    bottom: 62px;
  }
}

@media (max-width: 860px) {
  .split {
    grid-template-columns: minmax(0, 1fr);
  }

  .step {
    grid-template-columns: minmax(0, 1fr);
    gap: 0.7rem;
  }

  .step > .step-n {
    padding-top: 0;
  }
}

@media (max-width: 520px) {
  .hero-mark {
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
  }

  .hero-mark p {
    border-left: 0;
    border-top: 1px solid var(--rule);
    padding: 12px 0 0;
  }

  .hero-stats {
    flex-direction: column;
    gap: 0.35rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  * {
    animation-duration: 0.001s !important;
  }
}

@media print {
  .rail,
  .theme,
  .progress {
    display: none;
  }

  body {
    padding-left: 0;
    background: #fff;
    color: #000;
  }
}