/* DesigningROI — Shared design system */

*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
button, input, select, textarea { font: inherit; }

:root {
  --ground: #FCFCFB;
  --text-primary: rgba(0, 0, 0, 0.78);
  --text-secondary: #5C6166;
  --accent: #FF5900;
  --text-utility: #70757D;
  --tint: #F0F2F7;
  --rule: rgba(0, 0, 0, 0.08);
  --interactive: #2B6CB0;

  --serif: 'Libre Baskerville', Baskerville, Georgia, serif;
  --sans: 'Geist', system-ui, -apple-system, sans-serif;

  --type-primary: 18px;
  --type-body: 14px;
  --type-label: 12px;

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 16px;
  --space-4: 24px;
  --space-5: 40px;
  --space-6: 64px;

  --radius-panel: 8px;
  --radius-control: 6px;

  --reading-width: 680px;
}


body {
  background: var(--ground);
  color: var(--text-primary);
  font-family: var(--sans);
  font-size: var(--type-body);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

/* ---- Page shell ---- */

.page {
  max-width: 1020px;
  margin: 0 auto;
  padding: var(--space-5) var(--space-5) 80px;
}

.home-link {
  display: block;
  font-family: var(--serif);
  font-size: var(--type-body);
  font-weight: 400;
  color: var(--accent);
  text-decoration: none;
  margin-bottom: 48px;
}

h1, h2 {
  font-family: var(--sans);
  font-size: var(--type-primary);
  font-weight: 500;
  color: var(--text-primary);
  line-height: 1.4;
  margin-bottom: 10px;
}

/* ---- Phase question (serif) ---- */

.phase-question {
  font-family: var(--serif);
  font-size: var(--type-primary);
  font-weight: 400;
  line-height: 1.45;
  color: var(--text-primary);
  text-wrap: balance;
}

/* ---- Prompt list ---- */

.prompt-list {
  margin: 0;
  padding: 0;
  list-style: none;
  max-width: var(--reading-width);
}

.prompt-list li {
  padding: 10px 0;
  font-size: var(--type-body);
  color: var(--text-primary);
  line-height: 1.5;
  border-top: 1px solid var(--rule);
}

.prompt-list li:first-child {
  border-top: none;
  padding-top: 0;
}

.prompt-label {
  display: block;
  font-size: var(--type-label);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-utility);
  margin-bottom: 2px;
}

/* ---- Phase result ---- */

.phase-result {
  margin-top: 20px;
  padding-top: var(--space-3);
  border-top: 1px solid var(--rule);
}

.phase-result-label {
  font-size: var(--type-label);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-utility);
  margin-bottom: 2px;
}

.phase-result-value {
  font-family: var(--serif);
  font-size: var(--type-body);
  line-height: 1.5;
  color: var(--text-primary);
}

/* ---- Route list ---- */

.route-actions { margin-top: var(--space-3); }

.route-actions-label {
  font-size: var(--type-label);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-utility);
  margin-bottom: var(--space-2);
}

.route-list { margin: 0; padding: 0; list-style: none; }

.route-list li {
  padding: var(--space-1) 0;
  font-size: var(--type-body);
  color: var(--text-secondary);
  line-height: 1.5;
  border-top: 1px solid var(--rule);
}

.route-list li:first-child { border-top: none; }

.route-dest {
  font-weight: 600;
  color: var(--text-primary);
}

.route-link {
  font-family: inherit;
  font-size: inherit;
  font-weight: 600;
  color: var(--interactive);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  -webkit-appearance: none;
  appearance: none;
}

.route-link:hover {
  text-decoration: underline;
  text-underline-offset: 0.15em;
}

/* ---- Body text ---- */

.body-text {
  font-size: var(--type-body);
  color: var(--text-secondary);
  line-height: 1.5;
  max-width: var(--reading-width);
}

/* ---- Metadata label (uppercase) ---- */

.meta-label {
  font-size: var(--type-label);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-utility);
}

/* ---- Value argument chain ---- */

.value-chain {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.value-chain-node {
  font-size: var(--type-body);
  font-weight: 500;
  color: var(--text-secondary);
  padding: 6px 12px;
  border-radius: var(--radius-control);
  border: 1px solid var(--rule);
  background: var(--ground);
  white-space: nowrap;
}

.value-chain-node.specified {
  color: var(--text-primary);
}

.value-chain-node.supported {
  border-color: transparent;
  background: var(--tint);
  color: var(--text-primary);
}

.value-chain-node.unsupported {
  border-color: var(--interactive);
  color: var(--interactive);
}

.value-chain-conn {
  font-size: var(--type-body);
  font-weight: 500;
  color: var(--interactive);
}

/* ---- Evidence badges ---- */

.evidence-badge {
  font-size: var(--type-label);
  font-weight: 600;
  letter-spacing: 0.02em;
  flex-shrink: 0;
  padding: 2px 8px;
  border-radius: 3px;
}

.evidence-badge.supported {
  color: var(--text-utility);
  background: var(--tint);
}

.evidence-badge.gap {
  color: var(--interactive);
  background: transparent;
  border: 1px solid var(--interactive);
}

.evidence-badge.specified {
  color: var(--text-secondary);
  background: transparent;
  border: 1px solid var(--rule);
}

/* ---- Screen reader utility ---- */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* ---- Panel reveal animation ---- */

@keyframes panel-reveal {
  from { opacity: 0; transform: translateY(-6px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---- Copyright ---- */

.copyright {
  font-family: system-ui, -apple-system, sans-serif;
  font-size: var(--type-label);
  opacity: 0.5;
  margin-top: 48px;
}

.copyright a { color: inherit; text-decoration: none; }
.copyright a:hover { text-decoration: underline; }

/* ---- Responsive ---- */

@media (max-width: 600px) {
  .page { padding: 28px 20px 60px; }
  .value-chain {
    flex-direction: column;
    align-items: center;
    gap: 6px;
  }
  .value-chain-node { padding: 4px 8px; }
  .arrow-glyph { display: inline-block; transform: rotate(90deg); }

  /* Enlarge tap area of standalone text links without shifting layout */
  .copyright a { display: inline-block; padding: 5px 0; margin: -5px 0; }
  .cta a, .cta-link, .nav-link, .flow-restart { padding-block: 4px; margin-block: -4px; }
}