/* Plebum Dominium — design system
   Warm paper, sober ink, one amber accent. Offline-first: no webfonts, no frameworks. */

:root {
  --paper: #faf7f2;
  --header-bg: rgba(250, 247, 242, 0.92);
  --hover-bg: #f1ece2;
  --code-inline-bg: #f1ece2;
  --code-inline-ink: #7c2d12;
  --btn-ink: #ffffff;
  --card: #ffffff;
  --ink: #1c1917;
  --muted: #78716c;
  --line: #e7e0d5;
  --accent: #9a5f0a;
  --accent-soft: #fef3e2;
  --stop: #b91c1c;
  --stop-bg: #fef2f2;
  --warn: #9a5f0a;
  --warn-bg: #fffbeb;
  --tip: #166534;
  --tip-bg: #f0fdf4;
  --note: #1d4ed8;
  --note-bg: #eff6ff;
  --code-bg: #1c1917;
  --code-ink: #f5f0e8;
  --radius: 10px;
  --content-w: 72ch;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: Georgia, "Iowan Old Style", "Times New Roman", serif;
  font-size: 18px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
.kicker, .hero-kicker, .sidebar-label, .toc p, .header-sheet,
.callout-label, .you-need-label, .stage h2, .sheet-num, .card-num {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto,
    "Helvetica Neue", Arial, sans-serif;
}


/* ---------- dark mode: follows the visitor, toggle overrides ---------- */
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #0b0a08;
    --header-bg: rgba(11, 10, 8, 0.93);
    --hover-bg: #1c1712;
    --code-inline-bg: #1c1712;
    --code-inline-ink: #d9b06a;
    --btn-ink: #0b0a08;
    --card: #14110d;
    --ink: #f0e8d6;
    --muted: #9a8f78;
    --line: #2b251b;
    --accent: #c9a35c;
    --accent-soft: #231b0f;
    --stop: #f87171;
    --stop-bg: #2b1414;
    --warn: #c9a35c;
    --warn-bg: #2b2212;
    --tip: #4ade80;
    --tip-bg: #122419;
    --note: #7fb0ff;
    --note-bg: #141f30;
    --code-bg: #0e0b08;
    --code-ink: #f5f0e8;
  }
}
:root[data-theme="light"] {
  --paper: #faf7f2;
  --header-bg: rgba(250, 247, 242, 0.92);
  --hover-bg: #f1ece2;
  --code-inline-bg: #f1ece2;
  --code-inline-ink: #7c2d12;
  --card: #ffffff;
  --ink: #1c1917;
  --muted: #78716c;
  --line: #e7e0d5;
  --accent: #9a5f0a;
  --accent-soft: #fef3e2;
  --stop: #b91c1c;
  --stop-bg: #fef2f2;
  --warn: #9a5f0a;
  --warn-bg: #fffbeb;
  --tip: #166534;
  --tip-bg: #f0fdf4;
  --note: #1d4ed8;
  --note-bg: #eff6ff;
  --code-bg: #1c1917;
  --code-ink: #f5f0e8;
}
:root[data-theme="dark"] {
  --paper: #0b0a08;
  --header-bg: rgba(11, 10, 8, 0.93);
  --hover-bg: #1c1712;
  --code-inline-bg: #1c1712;
  --code-inline-ink: #d9b06a;
    --btn-ink: #0b0a08;
  --card: #14110d;
  --ink: #f0e8d6;
  --muted: #9a8f78;
  --line: #2b251b;
  --accent: #c9a35c;
  --accent-soft: #231b0f;
  --stop: #f87171;
  --stop-bg: #2b1414;
  --warn: #c9a35c;
  --warn-bg: #2b2212;
  --tip: #4ade80;
  --tip-bg: #122419;
  --note: #7fb0ff;
  --note-bg: #141f30;
  --code-bg: #0e0b08;
  --code-ink: #f5f0e8;
}

/* ---------- progress bar (CSS scroll timeline, zero JS) ---------- */
.progress {
  position: fixed; top: 0; left: 0; right: 0; height: 3px; z-index: 60;
  background: transparent; pointer-events: none;
}
.progress span {
  display: block; height: 100%; width: 100%;
  background: var(--accent);
  transform-origin: 0 50%; transform: scaleX(0);
  animation: progress linear;
  animation-timeline: scroll();
}
@keyframes progress { to { transform: scaleX(1); } }

/* ---------- header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  display: flex; align-items: center; gap: 0.75rem;
  padding: 0.7rem 1.25rem;
  background: var(--header-bg);
  backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--line);
}
.brand {
  font-weight: 700; letter-spacing: -0.01em; color: var(--ink);
  text-decoration: none; font-size: 1.05rem; white-space: nowrap;
}
.brand-mark { color: var(--accent); }
.header-sheet {
  margin-left: auto; font-size: 0.8rem; color: var(--muted);
  text-transform: uppercase; letter-spacing: 0.12em;
}
.menu-btn {
  display: none; border: 1px solid var(--line); background: var(--card);
  border-radius: 8px; font-size: 1.1rem; padding: 0.35rem 0.6rem; cursor: pointer;
}

/* ---------- layout ---------- */
.layout {
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr) 220px;
  gap: 2rem;
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 1.25rem;
  align-items: start;
}
main { min-width: 0; padding: 2.5rem 0 4rem; }
article { max-width: var(--content-w); }

/* ---------- sidebar ---------- */
.sidebar {
  position: sticky; top: 64px;
  max-height: calc(100vh - 80px); overflow-y: auto;
  padding: 1.5rem 0;
}
.sidebar-label {
  font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.14em;
  color: var(--muted); margin: 0 0 0.5rem 0.25rem;
}
.sidebar ul { list-style: none; margin: 0; padding: 0; }
.sidebar a {
  display: flex; align-items: center; gap: 0.6rem;
  padding: 0.45rem 0.6rem; border-radius: 8px;
  color: var(--ink); text-decoration: none; font-size: 0.92rem;
}
.sidebar a:hover { background: var(--hover-bg); }
.sidebar a.active { background: var(--accent-soft); font-weight: 600; }
.sidebar a.active .sheet-num { background: var(--accent); color: #fff; border-color: var(--accent); }
.sheet-num {
  flex: none; width: 1.9rem; height: 1.9rem;
  display: inline-flex; align-items: center; justify-content: center;
  border: 1px solid var(--line); border-radius: 50%;
  font-size: 0.72rem; font-weight: 700; color: var(--muted);
  background: var(--card);
}
.sheet-check {
  margin-left: auto; color: var(--tip); font-weight: 700;
  opacity: 0; transform: scale(0.6); transition: opacity 150ms, transform 150ms;
}
li.done .sheet-check { opacity: 1; transform: scale(1); }
li.done .sheet-title { color: var(--muted); }
.sidebar-note { font-size: 0.8rem; color: var(--muted); margin: 1rem 0.25rem 0; }
.scrim { display: none; }

/* ---------- TOC ---------- */
.toc-col { position: sticky; top: 64px; padding: 1.5rem 0; max-height: calc(100vh - 80px); overflow-y: auto; }
.toc p { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.14em; color: var(--muted); margin: 0 0 0.5rem; }
.toc ul { list-style: none; margin: 0; padding: 0; border-left: 2px solid var(--line); }
.toc li a {
  display: block; padding: 0.25rem 0 0.25rem 0.9rem; margin-left: -2px;
  border-left: 2px solid transparent;
  color: var(--muted); text-decoration: none; font-size: 0.86rem; line-height: 1.4;
}
.toc li a:hover { color: var(--ink); }
.toc li a.active { color: var(--accent); border-left-color: var(--accent); font-weight: 600; }

/* ---------- article typography ---------- */
.kicker {
  font-size: 0.75rem; font-weight: 600; text-transform: uppercase;
  letter-spacing: 0.18em; color: var(--accent); margin: 0 0 0.5rem;
}
h1 {
  font-size: 2.1rem; line-height: 1.15; letter-spacing: -0.02em;
  margin: 0 0 1.25rem;
}
h2 { font-size: 1.45rem; letter-spacing: -0.01em; margin: 2.5rem 0 0.75rem; }
h3 { font-size: 1.15rem; margin: 2rem 0 0.5rem; }
p { margin: 0 0 1rem; max-width: var(--content-w); }
a { color: var(--accent); }
a:hover { text-decoration: underline; }
article > ul, article > ol { margin: 0 0 1.25rem; padding-left: 1.4rem; }
li { margin-bottom: 0.4rem; }
li::marker { color: var(--accent); font-weight: 600; }
strong { font-weight: 700; }
hr { border: 0; border-top: 1px solid var(--line); margin: 2.5rem 0; }

/* ---------- code ---------- */
code {
  font-family: ui-monospace, "SF Mono", "Cascadia Code", "JetBrains Mono",
    "IBM Plex Mono", Menlo, Consolas, monospace;
  font-size: 0.88em;
  background: var(--code-inline-bg); color: var(--code-inline-ink);
  padding: 0.12em 0.4em; border-radius: 6px;
  overflow-wrap: break-word;
}
pre {
  position: relative; background: var(--code-bg); color: var(--code-ink);
  border-radius: var(--radius); padding: 1rem 1.1rem; overflow-x: auto;
  margin: 0 0 1.25rem; font-size: 0.9rem; line-height: 1.55;
}
pre code { background: none; color: inherit; padding: 0; }
.copy-btn {
  position: absolute; top: 0.5rem; right: 0.5rem;
  border: 1px solid rgba(255,255,255,0.25); background: rgba(255,255,255,0.08);
  color: var(--code-ink); border-radius: 6px; font-size: 0.75rem;
  padding: 0.25rem 0.6rem; cursor: pointer;
}
.copy-btn:hover { background: rgba(255,255,255,0.18); }
.copy-btn.copied { border-color: #4ade80; color: #4ade80; }

/* ---------- callouts (exactly four) ---------- */
.callout {
  border-radius: var(--radius); padding: 1rem 1.1rem 1rem 1.25rem;
  margin: 0 0 1.25rem; border-left: 4px solid;
  break-inside: avoid;
}
.callout p { margin: 0 0 0.5rem; }
.callout p:last-child { margin-bottom: 0; }
.callout-label { font-weight: 800; text-transform: uppercase; letter-spacing: 0.1em; font-size: 0.8rem; }
.callout-stop    { background: var(--stop-bg);  border-color: var(--stop); }
.callout-stop .callout-label { color: var(--stop); }
.callout-warning { background: var(--warn-bg);  border-color: var(--warn); }
.callout-warning .callout-label { color: var(--warn); }
.callout-tip     { background: var(--tip-bg);   border-color: var(--tip); }
.callout-tip .callout-label { color: var(--tip); }
.callout-note    { background: var(--note-bg);  border-color: var(--note); }
.callout-note .callout-label { color: var(--note); }
.callout ul { margin: 0.5rem 0 0; padding-left: 1.3rem; }

/* ---------- you-need box ---------- */
.you-need {
  background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 1.1rem 1.25rem; margin: 0 0 1.5rem;
  box-shadow: 0 1px 2px rgba(28,25,23,0.05);
}
.you-need-label {
  font-weight: 800; text-transform: uppercase; letter-spacing: 0.1em;
  font-size: 0.8rem; color: var(--accent); margin: 0 0 0.5rem;
}
.you-need ul { margin: 0; padding-left: 1.3rem; }

/* ---------- prev / next ---------- */
.prevnext-row { display: flex; gap: 1rem; margin-top: 3rem; }
.prevnext {
  flex: 1; display: block; padding: 1rem 1.2rem;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  text-decoration: none; color: var(--ink); font-weight: 600;
  transition: transform 150ms ease, box-shadow 150ms ease;
}
.prevnext:hover { transform: translateY(-2px); box-shadow: 0 4px 12px rgba(28,25,23,0.08); text-decoration: none; }
.prevnext.next { text-align: right; }

/* ---------- homepage ---------- */
.home .kicker { display: none; }
.home h1 { display: none; }
.hero { padding: 3rem 0 1rem; max-width: 60ch; }
.hero-kicker {
  font-size: 0.78rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.2em; color: var(--accent); margin: 0 0 0.75rem;
}
.hero h1 { display: block; font-size: 3rem; margin: 0 0 0.5rem; }
.hero-sub { font-size: 1.25rem; color: var(--accent); margin: 0 0 1rem; }
.btn {
  display: inline-block; background: var(--accent); color: var(--btn-ink);
  padding: 0.75rem 1.5rem; border-radius: 9px; font-weight: 700;
  text-decoration: none; margin: 0.5rem 0.5rem 0 0;
  transition: transform 150ms ease, box-shadow 150ms ease, background 150ms ease;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.25);
}
.btn:hover { transform: translateY(-1px); text-decoration: none; color: var(--btn-ink);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.35); filter: brightness(1.08); }
.btn-ghost { background: transparent; color: var(--accent); border: 1px solid var(--accent); box-shadow: none; }
.btn-ghost:hover { color: var(--accent); background: var(--accent-soft); filter: none; }
.stage { margin: 2.5rem 0; }
.stage h2 { font-size: 1.1rem; text-transform: uppercase; letter-spacing: 0.12em; color: var(--muted); }
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 0.9rem; }
.card {
  display: flex; align-items: center; gap: 0.8rem;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 1rem 1.1rem; text-decoration: none; color: var(--ink);
  transition: transform 150ms ease, box-shadow 150ms ease;
}
.card:hover { transform: translateY(-2px); box-shadow: 0 4px 14px rgba(28,25,23,0.09); text-decoration: none; }
.card-num {
  flex: none; width: 2.4rem; height: 2.4rem;
  display: inline-flex; align-items: center; justify-content: center;
  background: var(--accent-soft); color: var(--accent);
  border-radius: 50%; font-weight: 800; font-size: 0.85rem;
}
.card-title { font-weight: 600; line-height: 1.35; }

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--line); margin-top: 2rem;
  padding: 2rem 1.25rem 4rem; text-align: center;
  color: var(--muted); font-size: 0.88rem;
}
.site-footer p { margin: 0 0 0.4rem; }

/* ---------- mobile bar ---------- */
.mobilebar { display: none; }

/* ---------- reveal-on-scroll (diagrams/cards only, never body text) ---------- */
@media (prefers-reduced-motion: no-preference) {
  .card, .you-need {
    animation: rise 260ms ease-out both;
    animation-timeline: view();
    animation-range: entry 0% entry 60%;
  }
  @keyframes rise { from { opacity: 0.4; transform: translateY(10px); } }
}

/* ---------- responsive ---------- */
@media (max-width: 1020px) {
  .layout { grid-template-columns: 220px minmax(0, 1fr); }
  .toc-col { display: none; }
}
@media (max-width: 760px) {
  body { font-size: 16px; }
  .layout { grid-template-columns: minmax(0, 1fr); padding: 0 1rem; }
  .menu-btn { display: block; }
  .header-sheet { display: none; }
  .theme-btn { margin-left: auto; }
  .sidebar {
    position: fixed; top: 0; left: 0; bottom: 0; width: min(320px, 85vw);
    background: var(--paper); z-index: 70; padding: 1rem;
    transform: translateX(-105%); transition: transform 200ms ease;
    max-height: none; border-right: 1px solid var(--line);
  }
  body.nav-open .sidebar { transform: none; }
  body.nav-open .scrim {
    display: block; position: fixed; inset: 0; z-index: 65;
    background: rgba(28,25,23,0.4);
  }
  main { padding: 1.5rem 0 6rem; }
  h1 { font-size: 1.7rem; }
  .hero h1 { font-size: 2.2rem; }
  .prevnext-row { flex-direction: column; }
  .mobilebar {
    display: flex; align-items: center; justify-content: center;
    position: fixed; bottom: 0; left: 0; right: 0; z-index: 60;
    background: var(--header-bg); backdrop-filter: blur(8px);
    border-top: 1px solid var(--line);
    padding: 0.7rem 1rem; min-height: 44px;
    font-size: 0.82rem; color: var(--muted);
  }
  pre { font-size: 0.82rem; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}

/* ---------- theme toggle ---------- */
.theme-btn {
  border: 1px solid var(--line); background: var(--card);
  border-radius: 8px; padding: 0.35rem 0.55rem; cursor: pointer;
  color: var(--muted); line-height: 0;
}
.theme-btn:hover { color: var(--accent); border-color: var(--accent); }
.theme-btn svg { width: 18px; height: 18px; display: block; }
.theme-btn .moon { display: none; }
:root[data-theme="dark"] .theme-btn .sun { display: none; }
:root[data-theme="dark"] .theme-btn .moon { display: block; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) .theme-btn .sun { display: none; }
  :root:not([data-theme]) .theme-btn .moon { display: block; }
}

/* ---------- motion: hero entrance, keyring, reveals, diagrams ---------- */
@media (prefers-reduced-motion: no-preference) {
  .hero > * { animation: heroIn 520ms cubic-bezier(0.2, 0.7, 0.3, 1) both; }
  .hero > *:nth-child(2) { animation-delay: 90ms; }
  .hero > *:nth-child(3) { animation-delay: 180ms; }
  .hero > *:nth-child(4) { animation-delay: 260ms; }
  .hero > *:nth-child(5) { animation-delay: 340ms; }
  @keyframes heroIn { from { opacity: 0; transform: translateY(16px); } }

  .stage h2 { animation: heroIn 400ms ease-out both; animation-timeline: view(); animation-range: entry 0% entry 40%; }
  .card { transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease; }
  .card:hover { border-color: var(--accent); }
}

/* reveal fallback for browsers without scroll timelines (JS adds .reveal/.in) */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity 320ms ease, transform 320ms ease; }
.reveal.in { opacity: 1; transform: none; }

/* ---------- keyring: the 2-of-3 lock, animated ---------- */
.keyring {
  display: flex; align-items: center; gap: 1.75rem; flex-wrap: wrap;
  margin: 2.25rem 0 0.5rem; padding: 1.5rem;
  background: var(--card); border: 1px solid var(--line);
  border-radius: 14px; max-width: 560px;
}
.keys { display: flex; gap: 0.7rem; }
.key {
  width: 3.2rem; height: 3.2rem; border-radius: 50%;
  border: 2px solid var(--line); background: var(--paper);
  display: inline-flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 1.05rem; color: var(--muted);
}
.keyring-caption { flex: 1 1 100%; font-size: 0.95rem; color: var(--muted); margin: 0; }
.keyring-caption strong { color: var(--ink); }
.lockwrap { display: flex; flex-direction: column; align-items: center; }
.shackle {
  width: 34px; height: 24px;
  border: 5px solid var(--muted); border-bottom: 0;
  border-radius: 18px 18px 0 0; margin-bottom: -4px;
}
.lockbody {
  min-width: 76px; text-align: center;
  background: var(--paper); border: 2px solid var(--muted);
  border-radius: 10px; padding: 0.45rem 0.6rem;
  font-weight: 800; font-size: 0.85rem; color: var(--muted);
}
@media (prefers-reduced-motion: no-preference) {
  .key-a { animation: keyA 9s ease-in-out infinite; }
  .key-b { animation: keyB 9s ease-in-out infinite; }
  .key-c { animation: keyC 9s ease-in-out infinite; }
  .shackle { animation: unlock 9s ease-in-out infinite; }
  .lockbody { animation: lockbody 9s ease-in-out infinite; }
  /* A+B, then B+C, then A+C — any two open it */
  @keyframes keyA {
    0%, 24%, 62%, 86% { border-color: var(--accent); color: var(--accent); box-shadow: 0 0 0 5px var(--accent-soft); }
    29%, 57%, 91%, 100% { border-color: var(--line); color: var(--muted); box-shadow: none; }
  }
  @keyframes keyB {
    0%, 24%, 31%, 55% { border-color: var(--accent); color: var(--accent); box-shadow: 0 0 0 5px var(--accent-soft); }
    29%, 60%, 100% { border-color: var(--line); color: var(--muted); box-shadow: none; }
  }
  @keyframes keyC {
    31%, 55%, 62%, 86% { border-color: var(--accent); color: var(--accent); box-shadow: 0 0 0 5px var(--accent-soft); }
    0%, 26%, 60%, 100% { border-color: var(--line); color: var(--muted); box-shadow: none; }
  }
  @keyframes unlock {
    0%, 5%, 27%, 35%, 59%, 66%, 90%, 100% { transform: translateY(0); border-color: var(--muted); }
    8%, 24%, 40%, 55%, 71%, 86% { transform: translateY(-7px); border-color: var(--accent); }
  }
  @keyframes lockbody {
    0%, 5%, 27%, 35%, 59%, 66%, 90%, 100% { border-color: var(--muted); color: var(--muted); }
    8%, 24%, 40%, 55%, 71%, 86% { border-color: var(--accent); color: var(--accent); }
  }
}

/* ---------- sheet diagrams ---------- */
.sheet-diagram { margin: 0 0 2rem; }
.sheet-diagram img {
  display: block; width: 100%; height: auto;
  border-radius: 12px; border: 1px solid var(--line);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.12);
}
.sheet-diagram figcaption {
  margin-top: 0.6rem; font-size: 0.88rem; color: var(--muted);
}

/* ---------- spinning bitcoin ---------- */
.hero-title-row { display: flex; align-items: center; gap: 1.25rem; }
.hero-title-row h1 { margin: 0; }
.hero-pron { color: var(--muted); font-style: italic; margin: -0.25rem 0 1rem; }
.coin { width: 88px; height: 88px; flex: none; perspective: 500px; }
.coin span {
  display: flex; align-items: center; justify-content: center;
  width: 100%; height: 100%; border-radius: 50%;
  font-size: 2.5rem; font-weight: 800; color: #3d2c10;
  background: radial-gradient(circle at 32% 28%, #ecd9a8, #c9a35c 52%, #96702e 78%, #6b4d1d);
  box-shadow: 0 8px 22px rgba(180, 83, 9, 0.35),
    inset 0 2px 5px rgba(255, 255, 255, 0.55),
    inset 0 -4px 8px rgba(124, 45, 18, 0.4);
  border: 2px solid rgba(124, 45, 18, 0.35);
}
@media (prefers-reduced-motion: no-preference) {
  .coin span { animation: coinspin 7s linear infinite; }
  @keyframes coinspin { from { transform: rotateY(0deg); } to { transform: rotateY(360deg); } }
}
@media (max-width: 760px) {
  .coin { width: 64px; height: 64px; }
  .coin span { font-size: 1.8rem; }
}

/* ---------- two boots animation (airgap sheet: auto-playing loop) ---------- */
.boots-anim {
  display: grid; grid-template-columns: 1fr auto 1fr; gap: 1rem;
  align-items: stretch; margin: 0 0 2rem;
}
.boots-anim .boot {
  border: 1px solid var(--line); border-radius: 12px; padding: 1.25rem;
  background: var(--card); transition: border-color 300ms, box-shadow 300ms, opacity 300ms;
}
.boots-anim .boot-label {
  font-family: -apple-system, "Segoe UI", Inter, sans-serif;
  font-size: 0.7rem; font-weight: 700; text-transform: uppercase;
  letter-spacing: 0.16em; color: var(--accent); margin-bottom: 0.4rem;
}
.boots-anim .boot h4 { margin: 0 0 0.4rem; font-size: 1.15rem; }
.boots-anim .boot p { margin: 0 0 0.8rem; font-size: 0.92rem; color: var(--muted); }
.boots-anim .laptop {
  border: 2px solid var(--muted); border-radius: 8px 8px 0 0;
  border-bottom: 0; padding: 0.7rem; margin-bottom: 0.8rem; text-align: center;
}
.boots-anim .laptop .screen {
  border: 1px solid var(--line); border-radius: 4px; padding: 0.6rem;
  font-family: -apple-system, "Segoe UI", Inter, sans-serif; font-size: 0.8rem;
  color: var(--muted);
}
.boots-anim .laptop::after {
  content: ""; display: block; height: 6px; margin: 0.7rem -0.9rem -0.7rem;
  border: 2px solid var(--muted); border-top: 0; border-radius: 0 0 8px 8px;
}
.boots-anim .boot ul { margin: 0; padding-left: 1.2rem; font-size: 0.88rem; color: var(--muted); }
.boots-anim .boot li { margin-bottom: 0.25rem; }
.boots-anim .boot li::marker { color: var(--accent); }
.boots-anim .then {
  align-self: center; text-align: center;
  font-family: -apple-system, "Segoe UI", Inter, sans-serif;
  font-size: 0.72rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.1em;
  color: var(--btn-ink); background: var(--accent);
  border-radius: 8px; padding: 0.5rem 0.7rem; line-height: 1.5;
}
@media (prefers-reduced-motion: no-preference) {
  .boots-anim .boot1 { animation: aBoot1 9s ease-in-out infinite; }
  .boots-anim .boot2 { animation: aBoot2 9s ease-in-out infinite; }
  .boots-anim .then { animation: aThen 9s ease-in-out infinite; }
  @keyframes aBoot1 {
    0%, 32% { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); opacity: 1; }
    40%, 100% { border-color: var(--line); box-shadow: none; opacity: 0.35; }
  }
  @keyframes aBoot2 {
    0%, 48% { border-color: var(--line); box-shadow: none; opacity: 0.35; }
    56%, 88% { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); opacity: 1; }
    96%, 100% { border-color: var(--line); box-shadow: none; opacity: 0.35; }
  }
  @keyframes aThen {
    0%, 32%, 56%, 100% { transform: scale(1); opacity: 0.55; }
    40%, 48% { transform: scale(1.18); opacity: 1; }
  }
}
@media (max-width: 640px) {
  .boots-anim { grid-template-columns: 1fr; }
  .boots-anim .then { justify-self: center; }
}

/* ---------- signing sheet: the filling file (always dark) ---------- */
  .sign-anim .stage {
    position: relative; height: 380px;
    border: 1px solid var(--line); border-radius: 12px;
    background: #0e0c09; overflow: hidden;
    font-family: -apple-system, "Segoe UI", Inter, sans-serif;
  }
  .sign-anim .zone-on { position: absolute; top: 0; left: 0; right: 0; height: 34%; background: #12100c; border-bottom: 2px dashed var(--accent); }
  .sign-anim .zone-off { position: absolute; bottom: 0; left: 0; right: 0; height: 66%; background: #0e0c09; }
  .sign-anim .gaplabel { position: absolute; left: 50%; top: 34%; transform: translate(-50%, -50%); background: var(--paper); border: 1px solid var(--accent); color: var(--accent); font-size: 0.62rem; font-weight: 700; letter-spacing: 0.14em; padding: 3px 12px; border-radius: 999px; z-index: 3; }
  .sign-anim .redline {
    position: absolute; left: 50%; top: calc(34% + 82px); bottom: 0; width: 3px;
    background: #c0392b; z-index: 3;
    box-shadow: 0 0 12px rgba(192, 57, 43, 0.55);
  }
  .sign-anim .redline-tag {
    position: absolute; left: 50%; top: calc(34% + 52px); transform: translateX(-50%); z-index: 3;
    background: rgba(192, 57, 43, 0.12); border: 1px solid #c0392b; color: #e08070;
    font-size: 0.78rem; font-weight: 800; letter-spacing: 0.14em;
    padding: 6px 14px; border-radius: 6px; white-space: nowrap;
  }
  .sign-anim .usb {
    position: absolute; left: 50%; top: calc(34% + 22px); transform: translateX(-50%);
    width: 16px; height: 24px; background: #3a3530; border: 1px solid var(--muted);
    border-radius: 3px; z-index: 3;
  }
  .sign-anim .usb i {
    position: absolute; top: -10px; left: 50%; transform: translateX(-50%);
    width: 8px; height: 10px; background: #3a3530; border: 1px solid var(--muted);
    border-bottom: 0; border-radius: 2px 2px 0 0;
  }
  .sign-anim .ct-label {
    position: absolute; left: 24%; top: 7%; transform: translateX(-50%);
    font-size: 0.88rem; font-weight: 800; letter-spacing: 0.22em; color: var(--accent);
    opacity: 0; z-index: 2; white-space: nowrap;
  }
  .sign-anim .bc-label {
    position: absolute; right: 24%; top: 7%; transform: translateX(50%);
    font-size: 0.88rem; font-weight: 800; letter-spacing: 0.22em; color: var(--accent);
    opacity: 0; z-index: 2; white-space: nowrap;
  }
  .sign-anim .filebox {
    position: absolute; width: 36px; height: 46px; z-index: 4;
    background: transparent; overflow: hidden; border-radius: 6px;
    filter: drop-shadow(0 4px 8px rgba(0,0,0,0.6));
  }
  .sign-anim .filebox .fill {
    position: absolute; left: 0; top: 0; bottom: 0; width: 0%;
    background: var(--accent);
  }
  .sign-anim .filebox .outline { position: absolute; inset: 0; width: 100%; height: 100%; }
  .sign-anim .filebox .outline rect {
    fill: none; stroke: var(--ink); stroke-width: 2.5;
    stroke-dasharray: 1; stroke-dashoffset: 1;
  }
  .sign-anim .ped { position: absolute; width: 110px; text-align: center; }
  .sign-anim .ped .plate {
    width: 88px; height: 56px; margin: 0 auto 6px; border-radius: 8px;
    background: linear-gradient(135deg, #7a746e 0%, #b8b2ab 25%, #8a847e 50%, #6b6560 78%, #57534e 100%);
    border: 1px solid #44403c; position: relative;
  }
  .sign-anim .ped .plate i {
    display: block; height: 3px; margin: 7px 12px 0; background: rgba(0,0,0,0.35);
    border-radius: 2px; box-shadow: inset 0 1px 1px rgba(0,0,0,0.5);
  }
  .sign-anim .ped .plate i:first-child { margin-top: 10px; }
  .sign-anim .ped span { font-size: 0.64rem; color: var(--muted); letter-spacing: 0.08em; font-weight: 700; }
  .sign-anim .ped1 { left: 35%; bottom: 14%; transform: translateX(-50%); }
  .sign-anim .ped2 { left: 65%; bottom: 14%; transform: translateX(-50%); }
  .sign-anim .stamp { position: absolute; font-size: 0.85rem; font-weight: 800; letter-spacing: 0.1em; color: var(--accent); border: 2px solid var(--accent); border-radius: 8px; padding: 6px 14px; opacity: 0; background: rgba(11,10,8,0.9); z-index: 3; }
  .sign-anim .stamp1 { left: 35%; bottom: 32%; transform: translateX(-50%) rotate(-8deg); }
  .sign-anim .stamp2 { left: 65%; bottom: 32%; transform: translateX(-50%) rotate(-8deg); }
  .sign-anim .barcs { position: absolute; left: 76%; top: 20%; opacity: 0; z-index: 3; }
  .sign-anim .barcs i { position: absolute; border: 2px solid var(--accent); border-radius: 50%; border-left-color: transparent; border-bottom-color: transparent; transform: rotate(-45deg); }
  .sign-anim .barcs i:nth-child(1) { width: 36px; height: 36px; left: -18px; top: -18px; }
  .sign-anim .barcs i:nth-child(2) { width: 56px; height: 56px; left: -28px; top: -28px; }
  .sign-anim .barcs i:nth-child(3) { width: 76px; height: 76px; left: -38px; top: -38px; }
  .sign-anim .legend { margin: 1.1rem 0 0; padding: 0; list-style: none; }
  .sign-anim .legend li {
    position: relative; padding: 0.3rem 0 0.3rem 2rem; font-size: 0.9rem; color: var(--muted);
    border-top: 1px solid var(--line);
  }
  .sign-anim .legend li:first-child { border-top: 0; }
  .sign-anim .legend li b { color: var(--ink); }
  .sign-anim .legend li .n {
    position: absolute; left: 0; top: 0.35rem; width: 1.4rem; height: 1.4rem;
    border: 1px solid var(--accent); border-radius: 50%; color: var(--accent);
    font-size: 0.72rem; font-weight: 800; display: flex; align-items: center; justify-content: center;
    font-family: -apple-system, "Segoe UI", sans-serif;
  }
  .sign-anim .legend li i { color: var(--accent); }
  @media (prefers-reduced-motion: no-preference) {
    .sign-anim .ct-label { animation: e3Ct 22s linear infinite; }
    .sign-anim .bc-label { animation: e3Bc 22s linear infinite; }
    .sign-anim .filebox .outline rect { animation: e3Draw 22s linear infinite; }
    .sign-anim .filebox { animation: e3Box 22s ease-in-out infinite; }
    .sign-anim .filebox .fill { animation: e3Fill 22s linear infinite; }
    .sign-anim .ped1 .plate { animation: e3P1 22s ease-in-out infinite; }
    .sign-anim .ped2 .plate { animation: e3P2 22s ease-in-out infinite; }
    .sign-anim .stamp1 { animation: e3S1 22s linear infinite; }
    .sign-anim .stamp2 { animation: e3S2 22s linear infinite; }
    .sign-anim .barcs { animation: e3Barcs 22s linear infinite; }
    .sign-anim .usb, .sign-anim .usb i { animation: e3Usb 22s linear infinite; }
  }
  @keyframes e3Ct {
    0% { opacity: 0; } 1% { opacity: 1; } 2% { opacity: 0.25; } 3% { opacity: 1; }
    4% { opacity: 0.25; } 5%, 100% { opacity: 1; }
  }
  @keyframes e3Bc {
    0% { opacity: 0; }
    3%, 100% { opacity: 1; }
  }
  @keyframes e3Draw {
    0% { stroke-dashoffset: 1; }
    7%, 100% { stroke-dashoffset: 0; }
  }
  @keyframes e3Box {
    0% { left: 24%; top: 23%; opacity: 0; transform: translate(-50%, -50%) scale(0.7); }
    2%, 8% { left: 24%; top: 23%; opacity: 1; transform: translate(-50%, -50%) scale(1); }
    12% { left: 35%; top: 62%; opacity: 1; transform: translate(-50%, -50%) scale(1); }
    16%, 26% { left: 35%; top: 62%; opacity: 1; transform: translate(-50%, -50%) scale(1); }
    30% { left: calc(50% - 34px); top: 62%; opacity: 1; transform: translate(-50%, -50%) scale(1); }
    34%, 42% { left: calc(50% - 34px); top: 62%; opacity: 1; transform: translate(-50%, -50%) scale(1); }
    48% { left: 65%; top: 62%; opacity: 1; transform: translate(-50%, -50%) scale(1); }
    52%, 62% { left: 65%; top: 62%; opacity: 1; transform: translate(-50%, -50%) scale(1); }
    68% { left: 76%; top: 20%; opacity: 1; transform: translate(-50%, -50%) scale(1); }
    72%, 84% { left: 76%; top: 20%; opacity: 1; transform: translate(-50%, -50%) scale(1); }
    89%, 100% { left: 76%; top: 20%; opacity: 0; transform: translate(-50%, -50%) scale(1); }
  }
  @keyframes e3Fill {
    0%, 19% { width: 0%; }
    25%, 47% { width: 50%; }
    55%, 100% { width: 100%; }
  }
  @keyframes e3P1 {
    0%, 14% { transform: translateY(0); border-color: #44403c; box-shadow: inset 0 1px 2px rgba(255,255,255,0.3), 0 4px 10px rgba(0,0,0,0.5); }
    18%, 26% { transform: translateY(-8px); border-color: var(--accent); box-shadow: inset 0 1px 2px rgba(255,255,255,0.3), 0 0 26px rgba(201,163,92,0.7); }
    30%, 100% { transform: translateY(0); border-color: #44403c; box-shadow: inset 0 1px 2px rgba(255,255,255,0.3), 0 4px 10px rgba(0,0,0,0.5); }
  }
  @keyframes e3P2 {
    0%, 50% { transform: translateY(0); border-color: #44403c; box-shadow: inset 0 1px 2px rgba(255,255,255,0.3), 0 4px 10px rgba(0,0,0,0.5); }
    54%, 62% { transform: translateY(-8px); border-color: var(--accent); box-shadow: inset 0 1px 2px rgba(255,255,255,0.3), 0 0 26px rgba(201,163,92,0.7); }
    66%, 100% { transform: translateY(0); border-color: #44403c; box-shadow: inset 0 1px 2px rgba(255,255,255,0.3), 0 4px 10px rgba(0,0,0,0.5); }
  }
  @keyframes e3S1 { 0%, 23% { opacity: 0; } 27%, 88% { opacity: 1; } 92%, 100% { opacity: 0; } }
  @keyframes e3S2 { 0%, 57% { opacity: 0; } 61%, 88% { opacity: 1; } 92%, 100% { opacity: 0; } }
  @keyframes e3Barcs { 0%, 70% { opacity: 0; transform: scale(0.7); } 76%, 84% { opacity: 1; transform: scale(1.12); } 89%, 100% { opacity: 0; } }
  @keyframes e3Usb {
    0%, 32% { background: #3a3530; border-color: var(--muted); box-shadow: none; }
    35%, 37% { background: #c0392b; border-color: #e08070; box-shadow: 0 0 16px rgba(192, 57, 43, 0.9); }
    39%, 41% { background: #3a3530; border-color: var(--muted); box-shadow: none; }
    43%, 45% { background: #c0392b; border-color: #e08070; box-shadow: 0 0 16px rgba(192, 57, 43, 0.9); }
    47%, 100% { background: #3a3530; border-color: var(--muted); box-shadow: none; }
  }

  

  .sign-anim .sidetab {
    position: absolute; left: 0; z-index: 3;
    font-size: 0.80rem; font-weight: 800; letter-spacing: 0.16em;
    padding: 7px 18px 7px 11px; border-radius: 0 10px 10px 0; white-space: nowrap;
  }
  .sign-anim .st-on { top: calc(34% - 36px); background: #12100c; border: 1px solid var(--line); border-left: 0; color: var(--muted); }
  .sign-anim .st-off { top: calc(34% + 10px); background: #0e0c09; border: 1px solid var(--accent); border-left: 0; color: var(--accent); }

  
  @media (max-width: 640px) {
    .sign-anim .ct-label, .sign-anim .bc-label { font-size: 0.60rem; letter-spacing: 0.12em; }
    .sign-anim .sidetab { font-size: 0.55rem; padding: 3px 10px 3px 7px; }
    .sign-anim .stamp { font-size: 0.60rem; padding: 3px 8px; }
    .sign-anim .redline-tag { font-size: 0.55rem; padding: 3px 8px; }
  }
  @media (prefers-reduced-motion: reduce) {
    .sign-anim .filebox, .sign-anim .ped1 .plate, .sign-anim .ped2 .plate,
    .sign-anim .stamp1, .sign-anim .stamp2, .sign-anim .ct-label, .sign-anim .bc-label,
    .sign-anim .barcs i, .sign-anim .usb, .sign-anim .filebox .outline rect { animation: none !important; }
  }