:root {
  --ink: #171612;
  --paper: #eeeade;
  --paper-bright: #f8f5ec;
  --stone: #c8c1b0;
  --muted: #6c685e;
  --line: rgba(23, 22, 18, 0.18);
  --ember: #b54a2b;
  --night: #12110f;
  --max: 1240px;
  --serif: Georgia, "Times New Roman", serif;
  --sans: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
}
a { color: inherit; }
button, input { font: inherit; }
button { color: inherit; }
.skip-link { position: fixed; left: 1rem; top: -5rem; z-index: 100; padding: .8rem 1rem; background: var(--paper-bright); }
.skip-link:focus { top: 1rem; }

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
  padding: 0 max(24px, calc((100vw - var(--max)) / 2));
  border-bottom: 1px solid transparent;
  transition: background .25s ease, border-color .25s ease;
}
.site-header.is-scrolled { background: rgba(238, 234, 222, .94); border-color: var(--line); backdrop-filter: blur(12px); }
.wordmark { display: inline-flex; align-items: center; gap: .65rem; font-size: .78rem; font-weight: 800; letter-spacing: .22em; text-decoration: none; }
.wordmark-mark { color: var(--ember); font-size: 1.6rem; font-weight: 400; transform: translateY(-1px); }
.site-nav { display: flex; gap: clamp(1.25rem, 3vw, 2.75rem); }
.site-nav a { position: relative; font-size: .75rem; font-weight: 700; letter-spacing: .08em; text-decoration: none; text-transform: uppercase; }
.site-nav a::after { content: ""; position: absolute; left: 0; right: 100%; bottom: -.45rem; height: 1px; background: var(--ember); transition: right .2s ease; }
.site-nav a:hover::after, .site-nav a:focus-visible::after { right: 0; }
.menu-toggle { display: none; border: 0; background: none; font-size: .75rem; font-weight: 700; letter-spacing: .08em; text-transform: uppercase; }

.hero { min-height: 100svh; max-width: var(--max); margin: 0 auto; padding: 118px 24px 56px; display: grid; grid-template-columns: minmax(0, 1.06fr) minmax(420px, .94fr); align-items: center; gap: clamp(2rem, 6vw, 7rem); }
.eyebrow { margin: 0 0 1.4rem; color: var(--ember); font-size: .72rem; font-weight: 800; letter-spacing: .16em; text-transform: uppercase; }
h1, h2, blockquote { font-family: var(--serif); font-weight: 400; letter-spacing: -.04em; }
h1 { max-width: 790px; margin: 0; font-size: clamp(3.4rem, 7.3vw, 7.6rem); line-height: .88; }
h1 em { color: var(--ember); font-weight: 400; }
.hero-intro { max-width: 650px; margin: 2.2rem 0 0; font-size: clamp(1.08rem, 1.6vw, 1.35rem); line-height: 1.55; }
.hero-actions { display: flex; align-items: center; gap: 2rem; margin-top: 2.4rem; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 52px; padding: .9rem 1.25rem; border: 1px solid var(--ink); font-size: .76rem; font-weight: 800; letter-spacing: .08em; text-decoration: none; text-transform: uppercase; transition: background .2s ease, color .2s ease, transform .2s ease; }
.button:hover, .button:focus-visible { transform: translateY(-2px); }
.button-primary { background: var(--ink); color: var(--paper-bright); }
.button-primary:hover, .button-primary:focus-visible { background: var(--ember); border-color: var(--ember); }
.text-link { display: inline-flex; gap: .65rem; align-items: center; font-size: .78rem; font-weight: 800; letter-spacing: .06em; text-decoration-color: var(--ember); text-underline-offset: .35rem; text-transform: uppercase; }

.monument-stage { position: relative; min-height: 660px; display: grid; place-items: center; overflow: hidden; }
.monument { position: relative; z-index: 2; width: min(48%, 235px); filter: drop-shadow(26px 30px 18px rgba(18, 17, 15, .25)); animation: monument-in 1s cubic-bezier(.2,.75,.2,1) both; }
.monument-tip { width: 100%; aspect-ratio: 1.45; background: linear-gradient(135deg, #ebe6d9 0 48%, #aaa391 49% 100%); clip-path: polygon(50% 0, 100% 100%, 0 100%); }
.monument-face { position: relative; height: 440px; padding: 3.4rem 1rem; display: flex; flex-direction: column; align-items: center; gap: 2.6rem; background: linear-gradient(90deg, #cfc8b7 0 66%, #aaa391 67% 100%); clip-path: polygon(4% 0, 96% 0, 87% 100%, 13% 100%); color: rgba(23, 22, 18, .72); }
.monument-face::after { content: ""; position: absolute; inset: 0; opacity: .2; background-image: repeating-linear-gradient(13deg, transparent 0 8px, rgba(255,255,255,.5) 9px, transparent 10px); pointer-events: none; }
.inscription { position: relative; z-index: 1; font-family: var(--serif); letter-spacing: .14em; text-shadow: 0 1px rgba(255,255,255,.45), 0 -1px rgba(0,0,0,.25); }
.inscription-tallies { font-size: 1.05rem; }
.inscription-equation { font-size: 1rem; }
.inscription-geometry { font-size: 1.4rem; }
.inscription-orbit { margin-top: auto; font-size: 1.2rem; }
.monument-shadow { position: absolute; z-index: 1; bottom: 58px; width: 58%; height: 38px; border-radius: 50%; background: rgba(18,17,15,.3); filter: blur(13px); transform: rotate(5deg); }
.orbital-line { position: absolute; border: 1px solid rgba(23, 22, 18, .14); border-radius: 50%; }
.orbital-line-one { width: 520px; height: 200px; transform: rotate(-24deg); }
.orbital-line-two { width: 310px; height: 560px; transform: rotate(38deg); }
.stage-caption { position: absolute; bottom: 0; left: 0; display: flex; gap: 1rem; color: var(--muted); font-size: .67rem; letter-spacing: .1em; text-transform: uppercase; }
.stage-caption span { color: var(--ember); font-weight: 800; }

.section-rule { max-width: var(--max); margin: 0 auto; padding: clamp(5rem, 10vw, 9rem) 24px; border-top: 1px solid var(--line); }
.section-heading { max-width: 900px; }
h2 { margin: 0; font-size: clamp(2.8rem, 6vw, 6rem); line-height: .96; }
.section-heading > p:last-child:not(.eyebrow) { max-width: 660px; margin: 1.6rem 0 0; color: var(--muted); font-size: 1.1rem; }
.project-grid { display: grid; grid-template-columns: .8fr 1.2fr; gap: clamp(3rem, 9vw, 8rem); margin-top: 5rem; }
.project-lede { margin: 0; font-family: var(--serif); font-size: clamp(1.45rem, 2.4vw, 2.1rem); line-height: 1.35; }
.dependency-chain { border-top: 1px solid var(--ink); }
.chain-step { display: grid; grid-template-columns: 42px 130px 1fr; gap: 1rem; padding: 1.4rem 0; border-bottom: 1px solid var(--line); }
.chain-step span, .constraint-grid article > span, .roadmap-number { color: var(--ember); font-size: .68rem; font-weight: 800; }
.chain-step strong { font-size: .8rem; letter-spacing: .06em; text-transform: uppercase; }
.chain-step p { margin: 0; color: var(--muted); }

.lesson-shell { margin-top: 4.5rem; background: var(--night); color: var(--paper-bright); }
.lesson-controls { display: grid; grid-template-columns: repeat(5, 1fr); border-bottom: 1px solid rgba(248,245,236,.15); }
.lesson-tab { min-height: 68px; padding: 1rem; border: 0; border-right: 1px solid rgba(248,245,236,.15); background: transparent; color: rgba(248,245,236,.55); cursor: pointer; font-size: .72rem; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; text-align: left; transition: color .2s, background .2s; }
.lesson-tab:last-child { border-right: 0; }
.lesson-tab span { display: block; margin-bottom: .25rem; color: var(--ember); font-size: .62rem; }
.lesson-tab:hover, .lesson-tab:focus-visible { color: var(--paper-bright); background: rgba(255,255,255,.04); }
.lesson-tab.is-active { color: var(--paper-bright); box-shadow: inset 0 -3px var(--ember); }
.lesson-panel { display: grid; grid-template-columns: 1.2fr .8fr; min-height: 530px; outline: none; }
.lesson-artifact { display: grid; place-items: center; min-height: 500px; padding: 3rem; border-right: 1px solid rgba(248,245,236,.15); background: radial-gradient(circle at center, rgba(181,74,43,.08), transparent 55%); }
.artifact-sequence { width: 100%; display: flex; align-items: end; justify-content: center; gap: clamp(2rem, 6vw, 5rem); }
.artifact-group { display: flex; flex-direction: column; align-items: center; gap: 1.4rem; }
.artifact-label { color: rgba(248,245,236,.42); font-size: .65rem; letter-spacing: .13em; text-transform: uppercase; }
.tallies { display: flex; gap: .5rem; height: 120px; align-items: end; }
.tally { display: block; width: 4px; height: 100%; background: var(--paper-bright); box-shadow: 2px 0 var(--ember); transform: rotate(var(--tilt, 0deg)); }
.artifact-expression { font-family: var(--serif); font-size: clamp(2.5rem, 6vw, 5.8rem); letter-spacing: .08em; text-align: center; }
.artifact-expression .earned { color: var(--ember); }
.mapping { display: grid; grid-template-columns: repeat(3, 1fr); align-items: center; gap: 2rem; width: 100%; }
.mapping-item { display: grid; place-items: center; min-height: 210px; border: 1px solid rgba(248,245,236,.2); }
.mapping-item strong { display: block; color: var(--ember); font-family: var(--serif); font-size: 3.5rem; font-weight: 400; }
.mapping-item div { margin-top: 1.4rem; font-size: 1.6rem; letter-spacing: .2em; }
.lesson-explanation { padding: clamp(2rem, 5vw, 4.5rem); display: flex; flex-direction: column; }
.lesson-kicker { margin: 0 0 1rem; color: var(--ember); font-size: .68rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
.lesson-explanation h3 { max-width: 420px; margin: 0; font-family: var(--serif); font-size: clamp(2rem, 3.5vw, 3.5rem); font-weight: 400; line-height: 1.04; }
.lesson-explanation > p:not(.lesson-kicker) { color: rgba(248,245,236,.65); }
.inference { margin-top: auto; padding-top: 1.5rem; border-top: 1px solid rgba(248,245,236,.15); }
.inference span { color: rgba(248,245,236,.42); font-size: .64rem; letter-spacing: .1em; text-transform: uppercase; }
.inference p { margin: .5rem 0 0; }
.lesson-navigation { display: flex; align-items: center; justify-content: space-between; margin-top: 2rem; }
.lesson-navigation > span { color: rgba(248,245,236,.45); font-size: .68rem; }
.arrow-button { width: 44px; height: 44px; border: 1px solid rgba(248,245,236,.25); background: transparent; color: var(--paper-bright); cursor: pointer; transition: background .2s; }
.arrow-button:hover, .arrow-button:focus-visible { background: var(--ember); border-color: var(--ember); }
.arrow-button:disabled { opacity: .25; cursor: not-allowed; }

.roadmap-track { display: grid; grid-template-columns: repeat(5, 1fr); margin-top: 4.5rem; border-top: 1px solid var(--ink); border-bottom: 1px solid var(--ink); }
.roadmap-item { min-height: 340px; padding: 1.5rem; border-right: 1px solid var(--line); display: flex; flex-direction: column; }
.roadmap-item:last-child { border-right: 0; }
.roadmap-symbol { margin: 3rem 0 1.6rem; min-height: 42px; color: var(--muted); font-family: var(--serif); font-size: 1.5rem; letter-spacing: .12em; }
.roadmap-item.is-active .roadmap-symbol { color: var(--ember); }
.roadmap-item h3 { margin: 0; font-family: var(--serif); font-size: 1.55rem; font-weight: 400; }
.roadmap-item p { color: var(--muted); font-size: .88rem; }
.status { margin-top: auto; color: var(--muted); font-size: .62rem; font-weight: 800; letter-spacing: .1em; text-transform: uppercase; }
.roadmap-item.is-active .status { color: var(--ember); }

.constraint-grid { display: grid; grid-template-columns: repeat(3, 1fr); margin-top: 4.5rem; border-top: 1px solid var(--ink); border-left: 1px solid var(--line); }
.constraint-grid article { min-height: 255px; padding: 1.6rem; border-right: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.constraint-grid h3 { margin: 3rem 0 .75rem; font-family: var(--serif); font-size: 1.5rem; font-weight: 400; }
.constraint-grid p { margin: 0; color: var(--muted); font-size: .9rem; }
.method-link { margin-top: 2rem; text-align: right; }

.archive { display: grid; grid-template-columns: .8fr 1.2fr; gap: clamp(3rem, 9vw, 8rem); }
.archive-intro h2 { font-size: clamp(2.7rem, 4.8vw, 5rem); }
.archive-intro > p:last-child { max-width: 480px; color: var(--muted); }
.archive-links { border-top: 1px solid var(--ink); }
.archive-links a { display: grid; grid-template-columns: 40px 1fr auto; column-gap: 1rem; padding: 1.5rem 0; border-bottom: 1px solid var(--line); text-decoration: none; }
.archive-links a > span { grid-row: 1 / 3; color: var(--ember); font-size: .68rem; font-weight: 800; }
.archive-links strong { font-family: var(--serif); font-size: 1.4rem; font-weight: 400; }
.archive-links small { color: var(--muted); }
.archive-links b { grid-column: 3; grid-row: 1 / 3; align-self: center; font-weight: 400; transition: transform .2s; }
.archive-links a:hover b { transform: translate(3px,-3px); }

.closing { min-height: 70svh; padding: clamp(5rem, 10vw, 9rem) 24px; display: flex; flex-direction: column; align-items: center; justify-content: center; background: var(--ember); color: var(--paper-bright); text-align: center; }
.closing .eyebrow { color: var(--night); }
.closing blockquote { margin: 0 0 3rem; font-size: clamp(3rem, 7vw, 7.5rem); line-height: .95; }
.button-light { border-color: var(--paper-bright); }
.button-light:hover, .button-light:focus-visible { background: var(--paper-bright); color: var(--ember); }
.site-footer { min-height: 180px; padding: 3rem max(24px, calc((100vw - var(--max)) / 2)); display: grid; grid-template-columns: 1fr 1fr auto; align-items: center; gap: 2rem; background: var(--night); color: rgba(248,245,236,.68); font-size: .75rem; }
.site-footer .wordmark { color: var(--paper-bright); }
.site-footer a { text-underline-offset: .3rem; }

.reveal { opacity: 0; transform: translateY(24px); transition: opacity .65s ease, transform .65s ease; }
.reveal.is-visible { opacity: 1; transform: none; }
@keyframes monument-in { from { opacity: 0; transform: translateY(35px); } to { opacity: 1; transform: none; } }

@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; padding-top: 130px; }
  .monument-stage { min-height: 560px; }
  .monument-face { height: 370px; }
  .project-grid, .archive { grid-template-columns: 1fr; }
  .lesson-panel { grid-template-columns: 1fr; }
  .lesson-artifact { min-height: 420px; border-right: 0; border-bottom: 1px solid rgba(248,245,236,.15); }
  .roadmap-track { grid-template-columns: repeat(2, 1fr); }
  .roadmap-item { border-bottom: 1px solid var(--line); }
  .constraint-grid { grid-template-columns: repeat(2, 1fr); }
  .site-footer { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  .site-header { height: 66px; }
  .menu-toggle { display: block; }
  .site-nav { position: absolute; inset: 66px 0 auto; padding: 1.25rem 24px 1.5rem; display: none; flex-direction: column; background: var(--paper); border-bottom: 1px solid var(--line); }
  .site-nav.is-open { display: flex; }
  h1 { font-size: clamp(3.25rem, 17vw, 5rem); }
  .hero-actions { align-items: flex-start; flex-direction: column; gap: 1.25rem; }
  .monument-stage { min-height: 500px; }
  .monument { width: 47%; }
  .monument-face { height: 330px; gap: 2rem; }
  .orbital-line-one { width: 390px; }
  .orbital-line-two { width: 240px; height: 440px; }
  .chain-step { grid-template-columns: 36px 1fr; }
  .chain-step p { grid-column: 2; }
  .lesson-controls { display: flex; overflow-x: auto; }
  .lesson-tab { flex: 0 0 120px; }
  .lesson-artifact { min-height: 340px; padding: 1.5rem; }
  .artifact-sequence { gap: 1.5rem; }
  .tallies { height: 80px; gap: .3rem; }
  .mapping { gap: .5rem; }
  .mapping-item { min-height: 160px; }
  .mapping-item strong { font-size: 2.6rem; }
  .mapping-item div { font-size: 1rem; }
  .roadmap-track, .constraint-grid { grid-template-columns: 1fr; }
  .roadmap-item { min-height: 260px; border-right: 0; }
  .constraint-grid { border-left: 0; }
  .constraint-grid article { min-height: 220px; }
  .archive-links a { grid-template-columns: 30px 1fr auto; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; animation-iteration-count: 1 !important; transition-duration: .01ms !important; }
  .reveal { opacity: 1; transform: none; }
}