:root {
  color-scheme: light;
  --ink: #161a22;
  --muted: #5f6875;
  --line: #dfe5e2;
  --paper: #fbfcfb;
  --soft: #f1f5f3;
  --green: #0f8b62;
  --blue: #2364aa;
  --gold: #b7791f;
  --red: #c84630;
  --shadow: 0 16px 50px rgba(22, 26, 34, 0.08);
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--paper);
  color: var(--ink);
  line-height: 1.7;
}

a { color: inherit; text-underline-offset: 0.18em; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 72px;
  padding: 0.8rem clamp(1rem, 4vw, 3rem);
  background: rgba(251, 252, 251, 0.94);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.65rem;
  font-weight: 800;
  text-decoration: none;
}

.brand span { white-space: nowrap; }

.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(0.7rem, 2vw, 1.3rem);
  font-size: 0.96rem;
}

.site-nav a {
  color: var(--muted);
  text-decoration: none;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--ink);
}

.nav-toggle { display: none; }

main { width: 100%; }

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(320px, 0.9fr);
  gap: clamp(1.5rem, 5vw, 4rem);
  align-items: center;
  min-height: calc(100vh - 72px);
  padding: clamp(2rem, 5vw, 5rem) clamp(1rem, 5vw, 4.5rem);
  border-bottom: 1px solid var(--line);
}

.hero-copy {
  max-width: 760px;
}

.eyebrow {
  margin: 0 0 0.75rem;
  color: var(--green);
  font-size: 0.82rem;
  font-weight: 800;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1, h2, h3 {
  margin: 0;
  line-height: 1.16;
  letter-spacing: 0;
}

h1 {
  max-width: 920px;
  font-size: clamp(2.35rem, 5vw, 5.2rem);
}

h2 { font-size: clamp(1.55rem, 3vw, 2.45rem); }
h3 { font-size: 1.2rem; }

p { margin: 0 0 1rem; }

.hero-lede {
  max-width: 720px;
  margin-top: 1.25rem;
  color: var(--muted);
  font-size: 1.12rem;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 1.6rem;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 0.65rem 1rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  color: var(--ink);
  font-weight: 800;
  text-decoration: none;
}

.button.primary {
  border-color: var(--green);
  background: var(--green);
  color: #fff;
}

.hero-visual {
  min-height: 420px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #ffffff;
  box-shadow: var(--shadow);
  overflow: hidden;
}

.hero-visual canvas,
.canvas-wrap canvas {
  display: block;
  width: 100%;
  height: 100%;
}

.content-band,
.split-section,
.narrow-main,
.article-main,
.tool-main {
  padding: clamp(2rem, 5vw, 4.5rem) clamp(1rem, 5vw, 4.5rem);
}

.section-heading {
  max-width: 760px;
  margin-bottom: 1.6rem;
}

.text-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1.1rem;
}

.text-grid p,
.note-panel,
.item-card,
.glossary-item,
.tool-panel,
.takeaway {
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
}

.text-grid p {
  margin: 0;
  padding: 1.1rem;
}

.split-section {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(300px, 0.7fr);
  gap: clamp(1.25rem, 4vw, 3rem);
  align-items: center;
  background: var(--soft);
  border-block: 1px solid var(--line);
}

.steps {
  display: grid;
  gap: 0.8rem;
  margin: 1.2rem 0 0;
  padding-left: 1.25rem;
}

.diagram {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  overflow: hidden;
}

.diagram svg {
  display: block;
  width: 100%;
  height: auto;
  min-height: 220px;
}

.diagram figcaption {
  padding: 0.9rem 1rem;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.card-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.card-grid.compact {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.item-card {
  padding: 1rem;
}

.item-card h3 { margin-bottom: 0.55rem; }
.item-card p:last-child { margin-bottom: 0; color: var(--muted); }

.narrow-main,
.article-main,
.tool-main {
  max-width: 1180px;
  margin: 0 auto;
}

.page-title,
.article-header {
  max-width: 840px;
  margin-bottom: 2rem;
}

.page-title p,
.article-header p {
  color: var(--muted);
}

.article-main {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2rem;
}

.article-section {
  max-width: 820px;
  margin-top: 2rem;
}

.article-section h2 {
  margin-bottom: 0.8rem;
}

.article-section p {
  color: #2b313b;
}

.takeaway {
  max-width: 820px;
  margin-top: 2rem;
  padding: 1.2rem;
  border-left: 5px solid var(--green);
}

.related {
  border-top: 1px solid var(--line);
  padding-top: 2rem;
}

.tool-shell {
  display: grid;
  grid-template-columns: 320px minmax(0, 1fr);
  gap: 1rem;
  align-items: stretch;
}

.tool-panel {
  padding: 1rem;
}

.controls {
  display: grid;
  gap: 0.8rem;
}

.control {
  display: grid;
  grid-template-columns: 1fr 86px;
  gap: 0.5rem;
  align-items: center;
}

.control input {
  grid-column: 1 / -1;
  width: 100%;
}

.control output {
  justify-self: end;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}

.metric-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px solid var(--line);
}

.metric-row strong {
  font-size: 1.6rem;
  color: var(--green);
  font-variant-numeric: tabular-nums;
}

.tool-hint { color: var(--muted); }

.canvas-wrap {
  min-height: 520px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  overflow: hidden;
}

.glossary-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}

.glossary-item {
  padding: 1rem;
}

.glossary-item h2 {
  margin-bottom: 0.45rem;
  font-size: 1.25rem;
}

.note-panel {
  margin-top: 1.5rem;
  padding: 1.2rem;
}

.split-notes {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
  max-width: 920px;
}

.info-copy {
  border-top: 1px solid var(--line);
  padding-top: 1.4rem;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 2rem;
  padding: 2rem clamp(1rem, 5vw, 4.5rem);
  background: #111827;
  color: #f9fafb;
}

.site-footer p {
  max-width: 560px;
  color: #cbd5e1;
}

.site-footer nav {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-content: start;
}

@media (max-width: 880px) {
  .site-header {
    align-items: flex-start;
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: inline-flex;
    min-height: 38px;
    padding: 0.45rem 0.7rem;
    border: 1px solid var(--line);
    border-radius: 8px;
    background: #fff;
    font: inherit;
  }

  .site-nav {
    display: none;
    width: 100%;
    flex-direction: column;
    align-items: flex-start;
    padding-top: 0.5rem;
  }

  .site-nav.is-open { display: flex; }

  .hero,
  .split-section,
  .tool-shell {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: 0;
  }

  .hero-visual,
  .canvas-wrap {
    min-height: 360px;
  }

  .text-grid,
  .card-grid,
  .card-grid.compact,
  .split-notes,
  .glossary-grid {
    grid-template-columns: 1fr;
  }

  .site-footer {
    flex-direction: column;
  }
}

@media (max-width: 520px) {
  h1 { font-size: 2.25rem; }
  .hero-actions { flex-direction: column; align-items: stretch; }
  .button { width: 100%; }
  .control { grid-template-columns: 1fr 68px; }
}