/* ---------- tokens ---------- */
:root {
  --ink: #171D19;
  --ink-soft: #2A322C;
  --paper: #EFEEE6;
  --paper-raised: #E5E3D7;
  --brass: #BE7F35;
  --brass-deep: #96631F;
  --forest: #33513C;
  --line: #D8D4C6;
  --text: #1B1F17;
  --text-muted: #565F55;

  --font-display: "Newsreader", Georgia, serif;
  --font-body: "IBM Plex Sans", -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;

  --wrap: 1100px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

section[id], footer[id] { scroll-margin-top: 84px; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 1.05rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

.wrap {
  max-width: var(--wrap);
  margin: 0 auto;
  padding: 0 28px;
}

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 500;
  line-height: 1.12;
  margin: 0 0 0.5em;
  color: var(--ink);
}

h1 { font-size: clamp(2.6rem, 5vw, 4.2rem); letter-spacing: -0.01em; }
h2 { font-size: clamp(1.7rem, 3vw, 2.3rem); }
h3 { font-size: 1.25rem; font-weight: 600; }

p { max-width: 62ch; color: var(--text); }
p.lede { max-width: 46ch; font-size: 1.2rem; color: var(--ink-soft); }

a { color: inherit; }

::selection { background: var(--brass); color: var(--paper); }

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

/* ---------- buttons ---------- */
.btn {
  display: inline-block;
  font-family: var(--font-body);
  font-weight: 600;
  font-size: 0.98rem;
  text-decoration: none;
  padding: 0.85em 1.5em;
  border-radius: 3px;
  background: var(--ink);
  color: var(--paper);
  transition: background 0.15s ease, transform 0.15s ease;
}
.btn:hover { background: var(--forest); }
.btn:active { transform: translateY(1px); }

.btn-ghost {
  background: transparent;
  color: var(--ink);
  border: 1px solid var(--line);
}
.btn-ghost:hover { background: var(--paper-raised); }

.btn-small {
  padding: 0.55em 1.2em;
  font-size: 0.9rem;
}

/* ---------- header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(239, 238, 230, 0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--line);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 18px;
  padding-bottom: 18px;
  gap: 24px;
}

.wordmark {
  font-family: var(--font-display);
  font-size: 1.3rem;
  font-weight: 600;
  text-decoration: none;
  color: var(--ink);
  white-space: nowrap;
}
.wordmark span { color: var(--brass-deep); }

.site-nav {
  display: flex;
  gap: 28px;
  flex: 1;
  justify-content: center;
}
.site-nav a {
  text-decoration: none;
  color: var(--text-muted);
  font-size: 0.95rem;
  transition: color 0.15s ease;
}
.site-nav a:hover { color: var(--ink); }

/* ---------- hero ---------- */
.hero {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 48px;
  align-items: center;
  padding-top: 72px;
  padding-bottom: 64px;
}

.hero-actions {
  display: flex;
  gap: 16px;
  margin-top: 2em;
  flex-wrap: wrap;
}

.hero-visual { display: flex; justify-content: center; }

.stride-chart {
  width: 100%;
  max-width: 440px;
  height: auto;
}

.stride-chart .tick {
  fill: var(--text-muted);
  opacity: 0.55;
  transition: opacity 0.6s ease;
}

.stride-chart .stride {
  fill: var(--brass);
  transform-origin: left center;
  transform: scaleX(0);
  transition: transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

.stride-chart .stride:nth-child(1) { transition-delay: 0.05s; }
.stride-chart .stride:nth-child(2) { transition-delay: 0.18s; }
.stride-chart .stride:nth-child(3) { transition-delay: 0.31s; }
.stride-chart .stride:nth-child(4) { transition-delay: 0.44s; }

.stride-chart .baseline {
  stroke: var(--line);
  stroke-width: 1;
}

.stride-chart .axis-label {
  font-family: var(--font-mono);
  font-size: 9.5px;
  fill: var(--text-muted);
  opacity: 0.85;
}

.stride-chart .axis-label-after {
  opacity: 0;
  transition: opacity 0.5s ease 0.6s;
}

.stride-chart.in-view .tick { opacity: 0; }
.stride-chart.in-view .stride { transform: scaleX(1); }
.stride-chart.in-view .axis-label-after { opacity: 1; }

@media (prefers-reduced-motion: reduce) {
  .stride-chart .tick { opacity: 0; }
  .stride-chart .stride { transform: scaleX(1); }
  .stride-chart .axis-label-after { opacity: 1; }
}

/* ---------- promise ---------- */
.promise {
  padding-top: 24px;
  padding-bottom: 64px;
  border-top: 1px solid var(--line);
}

.promise-text {
  max-width: 68ch;
  font-size: 1.15rem;
  color: var(--ink-soft);
  margin-bottom: 2.5em;
}

.promise-facts {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding-top: 14px;
  border-top: 2px solid var(--brass);
}

.fact-number {
  font-family: var(--font-mono);
  font-size: 2.4rem;
  color: var(--ink);
  line-height: 1;
}

.fact-label {
  font-size: 0.92rem;
  color: var(--text-muted);
  max-width: 26ch;
}

/* ---------- process ---------- */
.process {
  padding-top: 64px;
  padding-bottom: 64px;
  border-top: 1px solid var(--line);
}

.process-list {
  list-style: none;
  margin: 2em 0 0;
  padding: 0;
  display: grid;
  gap: 36px;
}

.process-list li {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 20px;
  align-items: baseline;
}

.process-num {
  font-family: var(--font-mono);
  color: var(--brass-deep);
  font-size: 1rem;
}

.process-list h3 { margin-bottom: 0.3em; }
.process-list p { margin: 0; color: var(--text-muted); }

/* ---------- proof ---------- */
.proof {
  padding-top: 64px;
  padding-bottom: 64px;
  border-top: 1px solid var(--line);
}

.proof-text p { max-width: 68ch; }

.proof-steps {
  list-style: none;
  margin: 1.8em 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.proof-steps li {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  padding: 0.5em 0.9em;
  border: 1px solid var(--line);
  border-radius: 3px;
  color: var(--ink-soft);
  background: var(--paper-raised);
}

/* ---------- systems ---------- */
.systems {
  padding-top: 64px;
  padding-bottom: 64px;
  border-top: 1px solid var(--line);
}

.system-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  margin-top: 2em;
  border-top: 1px solid var(--line);
}

.system {
  padding: 28px 24px 28px 0;
  border-bottom: 1px solid var(--line);
}

.system:not(:last-child) {
  border-right: 1px solid var(--line);
  padding-right: 24px;
}
.system:nth-child(n+2) { padding-left: 24px; }

.system-role {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--brass-deep);
  text-transform: none;
  margin: -0.3em 0 1em;
}

.system p:last-child { color: var(--text-muted); margin: 0; }

/* ---------- about ---------- */
.about {
  padding-top: 64px;
  padding-bottom: 80px;
  border-top: 1px solid var(--line);
}
.about p { font-size: 1.1rem; }

/* ---------- footer ---------- */
.site-footer {
  background: var(--ink);
  color: var(--paper);
  padding-top: 56px;
  padding-bottom: 28px;
}

.site-footer h2 { color: var(--paper); }
.site-footer p { color: #C7CBC3; }

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
  padding-bottom: 40px;
}

.footer-cta .btn {
  background: var(--brass);
  color: var(--ink);
}
.footer-cta .btn:hover { background: var(--brass-deep); color: var(--paper); }

.footer-meta {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 8px;
  padding-top: 20px;
  border-top: 1px solid var(--ink-soft);
  font-size: 0.85rem;
  color: #8A9086;
}

/* ---------- responsive ---------- */
@media (max-width: 860px) {
  .site-nav { display: none; }
  .hero { grid-template-columns: 1fr; padding-top: 44px; }
  .hero-visual { order: -1; }
  .promise-facts { grid-template-columns: 1fr; gap: 20px; }
  .process-list li { grid-template-columns: 1fr; gap: 6px; }
  .system-list { grid-template-columns: 1fr; }
  .system, .system:not(:last-child) {
    border-right: none;
    padding-left: 0 !important;
    padding-right: 0 !important;
  }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}