:root {
  --paper: #f4f0e5;
  --paper-2: #e9e2d3;
  --cream: #fffdf6;
  --ink: #14261f;
  --ink-2: #243b32;
  --muted: #607168;
  --line: #c9c4b7;
  --mint: #c9f17d;
  --mint-2: #98c846;
  --coral: #ef7959;
  --gold: #e9b856;
  --blue: #657cf2;
  --display: Georgia, "Times New Roman", "Noto Serif SC", serif;
  --sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Noto Sans CJK SC", sans-serif;
  --mono: "SFMono-Regular", Consolas, "Liberation Mono", monospace;
  --shadow: 0 22px 70px rgba(20, 38, 31, 0.12);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; background: var(--paper); }
body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 86% 2%, rgba(201, 241, 125, 0.33), transparent 26rem),
    var(--paper);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.65;
  text-rendering: optimizeLegibility;
}

a { color: inherit; text-decoration: none; }
p { margin: 0 0 1em; }
strong { font-weight: 760; }
.shell { width: min(1180px, calc(100% - 48px)); margin-inline: auto; }

.skip-link {
  position: fixed;
  z-index: 100;
  top: 10px;
  left: 10px;
  padding: 9px 14px;
  color: var(--cream);
  background: var(--ink);
  transform: translateY(-170%);
}
.skip-link:focus { transform: translateY(0); }
:where(a, button):focus-visible { outline: 3px solid var(--blue); outline-offset: 3px; }

.topbar {
  position: sticky;
  z-index: 30;
  top: 0;
  border-bottom: 1px solid rgba(20, 38, 31, 0.14);
  background: rgba(244, 240, 229, 0.92);
  backdrop-filter: blur(18px);
}
.topbar-inner { display: flex; min-height: 68px; align-items: center; justify-content: space-between; gap: 24px; }
.brand { display: flex; align-items: center; gap: 11px; }
.brand-mark {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border-radius: 50%;
  background: var(--ink);
  color: var(--mint);
  font: 700 16px/1 var(--display);
}
.brand > span:last-child { display: grid; line-height: 1.1; }
.brand strong { font: 650 16px/1.2 var(--display); letter-spacing: -0.01em; }
.brand small { margin-top: 4px; color: var(--muted); font: 650 9px/1 var(--mono); letter-spacing: 0.08em; text-transform: uppercase; }
.topbar nav { display: flex; align-items: center; gap: 21px; font-size: 13px; font-weight: 700; }
.topbar nav a:not(.nav-paper):hover { color: #5d7c20; }
.nav-paper { padding: 9px 13px; border-radius: 4px; background: var(--ink); color: var(--cream); }

.hero { overflow: hidden; border-bottom: 1px solid var(--line); }
.hero-grid { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(360px, 0.75fr); gap: 76px; align-items: center; min-height: 730px; padding-block: 88px 92px; }
.status-row { display: flex; flex-wrap: wrap; gap: 14px 20px; align-items: center; margin-bottom: 34px; color: var(--muted); font: 650 10px/1.3 var(--mono); letter-spacing: 0.05em; text-transform: uppercase; }
.status-pill { display: inline-flex; align-items: center; gap: 8px; padding: 7px 10px; border: 1px solid rgba(20,38,31,.2); border-radius: 99px; color: var(--ink); background: rgba(255,255,255,.38); }
.status-pill i { width: 7px; height: 7px; border-radius: 50%; background: var(--gold); box-shadow: 0 0 0 4px rgba(233,184,86,.18); }
.eyebrow { margin: 0 0 13px; color: #587427; font: 750 10px/1.3 var(--mono); letter-spacing: .11em; text-transform: uppercase; }
.hero h1, .section-heading h2, .boundary-grid h2 { font-family: var(--display); font-weight: 500; letter-spacing: -0.04em; }
.hero h1 { max-width: 780px; margin: 0; font-size: clamp(51px, 6.3vw, 86px); line-height: .98; }
.hero h1 span { color: #5c7430; font-style: italic; }
.hero-deck { max-width: 770px; margin: 28px 0 18px; color: var(--ink-2); font: 500 clamp(20px, 2vw, 27px)/1.45 var(--display); }
.hero-lead { max-width: 760px; color: var(--muted); font-size: 17px; }
.hero-actions, .guide-actions { display: flex; flex-wrap: wrap; gap: 11px; align-items: center; margin-top: 31px; }
.button { display: inline-flex; min-height: 44px; align-items: center; justify-content: center; padding: 10px 17px; border: 1px solid var(--ink); border-radius: 4px; font-size: 13px; font-weight: 760; }
.button.primary { border-color: var(--ink); background: var(--ink); color: var(--cream); }
.button.primary:hover { background: #254035; }
.button.secondary { background: rgba(255,255,255,.42); }
.button.secondary:hover { background: var(--cream); }
.text-link { padding: 9px 3px; border-bottom: 1px solid var(--ink); font-size: 13px; font-weight: 720; }

.hero-model { position: relative; padding: 30px; border: 1px solid rgba(20,38,31,.18); border-radius: 12px; background: var(--ink); color: var(--cream); box-shadow: var(--shadow); }
.hero-model::before { content: ""; position: absolute; inset: 11px; pointer-events: none; border: 1px solid rgba(255,255,255,.08); border-radius: 7px; }
.model-label { margin: 0 0 22px; color: var(--mint); font: 730 10px/1 var(--mono); letter-spacing: .1em; text-transform: uppercase; }
.flow-node { position: relative; display: flex; min-height: 65px; flex-direction: column; justify-content: center; padding: 12px 15px; border: 1px solid rgba(255,255,255,.15); border-radius: 5px; background: rgba(255,255,255,.04); }
.flow-node small { color: rgba(255,255,255,.5); font: 650 9px/1.3 var(--mono); letter-spacing: .07em; text-transform: uppercase; }
.flow-node strong { margin-top: 6px; font: 500 20px/1.25 var(--display); }
.flow-node.belief { border-color: rgba(201,241,125,.45); background: rgba(201,241,125,.08); }
.flow-node.result { border-color: var(--mint); background: var(--mint); color: var(--ink); }
.flow-node.result small { color: rgba(20,38,31,.58); }
.flow-arrow { display: block; height: 24px; color: rgba(255,255,255,.46); text-align: center; line-height: 24px; }
.belief-pair { display: grid; grid-template-columns: 1fr 42px 1fr; gap: 8px; align-items: center; }
.belief-pair span { padding: 10px; border-radius: 4px; background: #2c473c; text-align: center; font-family: var(--display); }
.belief-pair i { color: var(--mint); text-align: center; font-style: normal; }
.hero-model > p { margin: 20px 2px 0; color: rgba(255,255,255,.52); font-size: 11px; line-height: 1.5; }

.truth-strip { background: var(--ink); color: var(--cream); }
.truth-grid { display: grid; grid-template-columns: repeat(3, 1fr); }
.truth-grid > div { min-height: 112px; padding: 25px 28px; border-left: 1px solid rgba(255,255,255,.13); }
.truth-grid > div:last-child { border-right: 1px solid rgba(255,255,255,.13); }
.truth-grid span { display: block; margin-bottom: 9px; color: var(--mint); font: 700 9px/1 var(--mono); letter-spacing: .1em; text-transform: uppercase; }
.truth-grid strong { font: 500 16px/1.45 var(--display); }

.section { padding-block: 108px; scroll-margin-top: 60px; }
.section-tint { background: #e7e0d0; }
.section-dark { background: var(--ink); color: var(--cream); }
.section-paper { border-block: 1px solid var(--line); background: #eee8dc; }
.section-heading { margin-bottom: 49px; }
.section-heading h2, .boundary-grid h2 { max-width: 880px; margin: 0; font-size: clamp(39px, 4.5vw, 62px); line-height: 1.05; }
.split-heading { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(260px, .65fr); gap: 72px; align-items: end; }
.split-heading > p { margin: 0; color: var(--muted); }
.light-heading .eyebrow { color: var(--mint); }
.light-heading > p { color: rgba(255,255,255,.57); }

.thesis-card { display: grid; grid-template-columns: 1.1fr .9fr; gap: 0; overflow: hidden; border: 1px solid var(--ink); background: var(--cream); box-shadow: 12px 12px 0 var(--ink); }
.thesis-card > p { margin: 0; padding: 32px; font: 500 22px/1.5 var(--display); }
.thesis-card .boundary-note { border-left: 1px solid var(--ink); background: var(--mint); color: var(--ink); font: 650 14px/1.65 var(--sans); }

.two-lanes { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.lane { min-height: 460px; padding: 31px; border: 1px solid var(--ink); background: rgba(255,255,255,.25); }
.lane-top { display: flex; justify-content: space-between; color: var(--muted); font: 700 9px/1 var(--mono); letter-spacing: .09em; text-transform: uppercase; }
.lane-top b { color: var(--ink); }
.lane h3 { margin: 32px 0 12px; font: 500 34px/1.1 var(--display); }
.lane p { color: var(--muted); }
.disco-lane { background: var(--ink); color: var(--cream); }
.disco-lane .lane-top, .disco-lane p { color: rgba(255,255,255,.58); }
.disco-lane .lane-top b { color: var(--mint); }
.row-cloud { display: flex; min-height: 145px; align-items: center; justify-content: space-evenly; padding: 20px; }
.row-cloud i { display: grid; width: calc(42px * var(--size)); height: calc(42px * var(--size)); place-items: center; border-radius: 50%; background: rgba(93,124,32,var(--alpha)); color: var(--cream); font: 700 11px/1 var(--mono); font-style: normal; }
.belief-cloud { position: relative; height: 145px; margin-top: 6px; border: 1px dashed rgba(255,255,255,.18); border-radius: 72px; }
.belief-cloud i { position: absolute; left: var(--x); top: var(--y); display: grid; width: 39px; height: 39px; place-items: center; border-radius: 50%; background: rgba(201,241,125,var(--alpha)); color: var(--ink); font: 750 11px/1 var(--mono); font-style: normal; transform: translate(-50%,-50%); }
.lane-formula { padding: 15px; border-top: 1px solid currentColor; font: 500 16px/1.5 var(--display); text-align: center; }
.disco-lane .lane-formula { border-color: rgba(255,255,255,.2); color: var(--mint); }
.sample-space-warning { display: grid; grid-template-columns: 280px 1fr; gap: 36px; margin-top: 18px; padding: 25px 28px; border: 1px solid var(--coral); background: #fae6dd; }
.sample-space-warning strong { font: 500 22px/1.3 var(--display); }
.sample-space-warning p { margin: 0; color: #624b42; }

.similarity-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 18px; }
.similarity-card { position: relative; padding: 34px; border: 1px solid var(--ink); background: var(--cream); }
.primary-card { box-shadow: 10px 10px 0 var(--mint); }
.card-number { position: absolute; top: 22px; right: 24px; color: #b9b5aa; font: 500 55px/1 var(--display); }
.card-status { display: inline-block; margin-bottom: 26px; padding: 6px 8px; border-radius: 2px; background: var(--paper-2); font: 700 9px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; }
.primary-card .card-status { background: var(--mint); }
.similarity-card h3 { max-width: 75%; margin: 0 0 17px; font: 500 32px/1.1 var(--display); }
.formula { overflow-x: auto; margin: 21px 0; padding: 15px; border-left: 3px solid var(--mint-2); background: var(--paper); }
.similarity-card ul, .boundary-list { margin: 22px 0 0; padding-left: 20px; }
.similarity-card li { margin-bottom: 7px; color: var(--muted); }
.danger-card { display: grid; grid-template-columns: .9fr 1fr; gap: 22px 34px; margin-top: 18px; padding: 30px 34px; border: 1px solid #8a3a29; background: #3a201b; color: #fff8f4; }
.danger-card span { color: #ffb39e; font: 700 9px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; }
.danger-card h3 { margin: 10px 0 0; font: 500 28px/1.15 var(--display); }
.danger-formula { margin: 0; border-color: var(--coral); background: rgba(255,255,255,.05); }
.danger-card > p { grid-column: 1 / -1; margin: 0; color: rgba(255,255,255,.66); }

.algorithm-flow { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: rgba(255,255,255,.13); }
.algorithm-flow > div { min-height: 177px; padding: 25px; background: #1b3128; }
.algorithm-flow span { color: var(--mint); font: 700 10px/1 var(--mono); }
.algorithm-flow strong { display: block; margin: 16px 0 9px; font: 500 21px/1.2 var(--display); }
.algorithm-flow p { margin: 0; color: rgba(255,255,255,.57); font-size: 13px; }
.estimator-formula { margin-top: 26px; padding: 28px 32px; border: 1px solid var(--mint); background: #0e211a; text-align: center; }
.estimator-formula > span { color: var(--mint); font: 700 9px/1 var(--mono); letter-spacing: .1em; text-transform: uppercase; }
.estimator-formula mjx-container { font-size: 130% !important; }
.diagnostic-row { display: grid; grid-template-columns: repeat(4,1fr); margin-top: 14px; border: 1px solid rgba(255,255,255,.16); }
.diagnostic-row > div { padding: 18px; border-right: 1px solid rgba(255,255,255,.16); }
.diagnostic-row > div:last-child { border: 0; }
.diagnostic-row span { display: block; color: rgba(255,255,255,.45); font: 700 9px/1 var(--mono); text-transform: uppercase; }
.diagnostic-row strong { display: block; margin-top: 8px; color: var(--mint); font-size: 12px; }

.ladder { display: grid; gap: 0; margin: 0; padding: 0; list-style: none; counter-reset: level; }
.ladder > li { display: grid; grid-template-columns: 120px 1fr; border-top: 1px solid var(--line); }
.ladder > li:last-child { border-bottom: 1px solid var(--line); }
.ladder > li > span { padding: 27px 0; color: #5f7c25; font: 750 10px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; }
.ladder > li > div { padding: 24px 28px; border-left: 1px solid var(--line); }
.ladder h3 { margin: 0 0 7px; font: 500 27px/1.2 var(--display); }
.ladder p { margin: 0; color: var(--muted); }
.ladder .formula { margin-bottom: 14px; }
.ladder .open-level { background: #efe0db; }
blockquote { margin: 34px 0 0; padding: 26px 30px; border-left: 5px solid var(--ink); background: var(--mint); font: 500 19px/1.55 var(--display); }

.boundary-grid { display: grid; grid-template-columns: .92fr 1.08fr; gap: 85px; align-items: start; }
.boundary-grid > div > p:last-child { margin-top: 24px; color: var(--muted); }
.boundary-list { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
.boundary-list li { position: relative; padding: 17px 18px 17px 41px; border-bottom: 1px solid var(--line); }
.boundary-list li::before { content: "×"; position: absolute; left: 10px; color: var(--coral); font: 600 20px/1 var(--display); }

.reading-layout { display: grid; grid-template-columns: 1.1fr .9fr; gap: 18px; align-items: stretch; }
.guide-card { padding: 36px; border: 1px solid var(--ink); background: var(--ink); color: var(--cream); }
.recommended { display: inline-block; padding: 6px 9px; background: var(--mint); color: var(--ink); font: 700 9px/1 var(--mono); text-transform: uppercase; }
.guide-card h3 { margin: 24px 0 12px; font: 500 36px/1.1 var(--display); }
.guide-card > p { color: rgba(255,255,255,.58); }
.guide-card .button.primary { border-color: var(--mint); background: var(--mint); color: var(--ink); }
.guide-card .button.secondary { border-color: rgba(255,255,255,.35); background: transparent; color: var(--cream); }
.guide-card ol { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0 24px; margin: 33px 0 0; padding: 20px 0 0 23px; border-top: 1px solid rgba(255,255,255,.17); color: rgba(255,255,255,.71); font-size: 13px; }
.guide-card li { padding: 6px 6px 6px 2px; }
.reading-paths { display: grid; grid-template-columns: repeat(2,1fr); gap: 1px; border: 1px solid var(--line); background: var(--line); }
.reading-paths article { padding: 25px; background: var(--cream); }
.reading-paths span { color: #5e7b28; font: 750 9px/1 var(--mono); letter-spacing: .08em; text-transform: uppercase; }
.reading-paths h3 { margin: 15px 0 8px; font: 500 22px/1.2 var(--display); }
.reading-paths p { margin: 0; color: var(--muted); font-size: 13px; }

.artifact-section { background: #11241d; color: var(--cream); }
.artifact-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 1px; background: rgba(255,255,255,.16); }
.artifact-grid a { display: flex; min-height: 160px; flex-direction: column; justify-content: end; padding: 23px; background: #1a3027; transition: background .18s ease, transform .18s ease; }
.artifact-grid a:hover { z-index: 2; background: #2b483c; transform: translateY(-3px); }
.artifact-grid span { color: var(--mint); font: 700 9px/1 var(--mono); text-transform: uppercase; }
.artifact-grid strong { margin: 13px 0 6px; font: 500 22px/1.2 var(--display); }
.artifact-grid small { color: rgba(255,255,255,.5); }
.feedback-box { display: grid; grid-template-columns: 1fr .8fr auto; gap: 30px; align-items: center; margin-top: 25px; padding: 28px; border: 1px solid var(--mint); }
.feedback-box span { color: var(--mint); font: 700 9px/1 var(--mono); text-transform: uppercase; }
.feedback-box h3 { margin: 9px 0 0; font: 500 23px/1.25 var(--display); }
.feedback-box > p { margin: 0; color: rgba(255,255,255,.57); font-size: 13px; }
.feedback-box .button { white-space: nowrap; border-color: var(--mint); background: var(--mint); color: var(--ink); }

footer { border-top: 1px solid #31493f; background: #0d1e18; color: var(--cream); }
.footer-inner { display: flex; min-height: 145px; align-items: center; justify-content: space-between; gap: 40px; }
.footer-inner strong { font: 500 26px/1 var(--display); }
.footer-inner p, .footer-inner span { margin: 7px 0 0; color: rgba(255,255,255,.48); font-size: 12px; }
.footer-inner > div:last-child { display: grid; gap: 9px; text-align: right; }
.footer-inner a { color: var(--mint); font-size: 13px; font-weight: 700; }

mjx-container[jax="CHTML"][display="true"] { margin-block: .5em !important; overflow-x: auto; overflow-y: hidden; padding-block: 2px; }

@media (max-width: 980px) {
  .topbar nav a:not(.nav-paper) { display: none; }
  .hero-grid { grid-template-columns: 1fr; gap: 42px; min-height: auto; padding-block: 70px; }
  .hero-model { max-width: 600px; }
  .truth-grid, .algorithm-flow, .artifact-grid { grid-template-columns: repeat(2,1fr); }
  .truth-grid > div:last-child { grid-column: 1 / -1; }
  .split-heading, .boundary-grid { grid-template-columns: 1fr; gap: 26px; }
  .diagnostic-row { grid-template-columns: repeat(2,1fr); }
  .diagnostic-row > div:nth-child(2) { border-right: 0; }
  .diagnostic-row > div:nth-child(-n+2) { border-bottom: 1px solid rgba(255,255,255,.16); }
  .reading-layout { grid-template-columns: 1fr; }
  .feedback-box { grid-template-columns: 1fr; }
}

@media (max-width: 720px) {
  .shell { width: min(100% - 28px, 1180px); }
  .topbar-inner { min-height: 61px; }
  .nav-paper { padding: 8px 10px; }
  .hero-grid { padding-block: 50px 58px; }
  .status-row { margin-bottom: 26px; }
  .hero h1 { font-size: clamp(42px, 12vw, 61px); }
  .hero-deck { font-size: 20px; }
  .hero-actions .button, .hero-actions .text-link { width: 100%; }
  .hero-model { padding: 22px; }
  .truth-grid, .two-lanes, .similarity-grid, .algorithm-flow, .artifact-grid { grid-template-columns: 1fr; }
  .truth-grid > div, .truth-grid > div:last-child { grid-column: auto; border-right: 1px solid rgba(255,255,255,.13); border-bottom: 1px solid rgba(255,255,255,.13); }
  .section { padding-block: 74px; }
  .section-heading { margin-bottom: 33px; }
  .section-heading h2, .boundary-grid h2 { font-size: clamp(35px, 10vw, 48px); }
  .thesis-card { grid-template-columns: 1fr; box-shadow: 7px 7px 0 var(--ink); }
  .thesis-card .boundary-note { border-top: 1px solid var(--ink); border-left: 0; }
  .lane { min-height: auto; padding: 25px; }
  .sample-space-warning { grid-template-columns: 1fr; gap: 12px; }
  .similarity-card { padding: 27px 23px; }
  .primary-card { box-shadow: 6px 6px 0 var(--mint); }
  .danger-card { grid-template-columns: 1fr; padding: 25px 22px; }
  .danger-card > p { grid-column: auto; }
  .algorithm-flow > div { min-height: auto; }
  .estimator-formula { padding-inline: 12px; }
  .ladder > li { min-width: 0; grid-template-columns: 70px minmax(0, 1fr); }
  .ladder > li > div { min-width: 0; padding: 21px 14px; }
  .guide-card { padding: 27px 22px; }
  .guide-card ol { grid-template-columns: 1fr; }
  .reading-paths { grid-template-columns: 1fr; }
  .footer-inner { flex-direction: column; align-items: flex-start; justify-content: center; padding-block: 36px; }
  .footer-inner > div:last-child { text-align: left; }
}

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