/* Design tokens. §26–27.
   Palette checked for WCAG 2.2 AA text contrast against its paired background at time of writing;
   re-check with a contrast tool before production publication (documented limitation, see report). */

:root {
  /* Colour — restrained archival palette */
  --color-paper: #faf7f0;          /* warm paper/off-white background */
  --color-ink: #1a1815;            /* near-black ink, not pure black */
  --color-ink-muted: #4a453e;
  --color-rule: #d8d0c0;
  --color-institutional-blue: #1f3a5f;
  --color-institutional-blue-dark: #16283f;
  --color-ochre: #a35c1c;          /* restrained deep saffron/ochre accent, used sparingly */
  --color-slate: #4b5d63;

  /* Evidence tier colours — never the sole signifier; always paired with the letter + label */
  --tier-a-bg: #e7f0e7; --tier-a-fg: #1e4620; --tier-a-border: #5a8a5c;
  --tier-b-bg: #e7eef5; --tier-b-fg: #16283f; --tier-b-border: #4a6fa1;
  --tier-c-bg: #f7efe0; --tier-c-fg: #6b4a12; --tier-c-border: #a35c1c;
  --tier-d-bg: #f2e9f2; --tier-d-fg: #4a2b4a; --tier-d-border: #8a5c8a;
  --tier-x-bg: #f5e5e3; --tier-x-fg: #6b1f16; --tier-x-border: #a3391c;

  /* Typography */
  --font-serif: "Source Serif 4", Georgia, "Times New Roman", serif;    /* editorial narrative */
  --font-sans: "Inter", "Segoe UI", system-ui, sans-serif;              /* metadata, nav, UI */
  --font-gurmukhi: "Noto Sans Gurmukhi", sans-serif;                    /* future Punjabi content */

  --step-0: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --step-1: clamp(1.25rem, 1.15rem + 0.5vw, 1.5rem);
  --step-2: clamp(1.75rem, 1.5rem + 1vw, 2.25rem);
  --step-3: clamp(2.25rem, 1.9rem + 1.5vw, 3rem);
  --line-length-max: 68ch;

  /* Spacing */
  --space-1: 0.5rem;
  --space-2: 1rem;
  --space-3: 1.5rem;
  --space-4: 2.5rem;
  --space-5: 4rem;

  --radius: 3px; /* archival, not app-like — minimal rounding */
  --focus-ring: 3px solid var(--color-ochre);
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-paper: #171613;
    --color-ink: #ece7dc;
    --color-ink-muted: #b9b2a3;
    --color-rule: #3a352c;
    /* Light-mode institutional blue (#1f3a5f) fails WCAG AA (1.58:1) against this dark
       background; lightened to #6f9bc9 (6.21:1) — found by Lighthouse contrast audit. */
    --color-institutional-blue: #6f9bc9;
  }
}

@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; }
}



* { box-sizing: border-box; }
html { scroll-behavior: auto; }
@media (prefers-reduced-motion: no-preference) { html { scroll-behavior: smooth; } }

body {
  margin: 0;
  background: var(--color-paper);
  color: var(--color-ink);
  font-family: var(--font-serif);
  font-size: var(--step-0);
  line-height: 1.6;
}

.skip-link {
  position: absolute; left: -999px; top: 0; z-index: 100;
  background: var(--color-institutional-blue); color: white;
  padding: var(--space-1) var(--space-2);
}
.skip-link:focus { left: var(--space-2); top: var(--space-2); }

a { color: var(--color-institutional-blue); }
a:focus-visible, button:focus-visible, summary:focus-visible, [tabindex]:focus-visible {
  outline: var(--focus-ring); outline-offset: 2px;
}

.site-header, .site-footer { font-family: var(--font-sans); }
.site-header {
  border-bottom: 1px solid var(--color-rule);
  padding: var(--space-2) var(--space-3);
  display: flex; align-items: baseline; justify-content: space-between; flex-wrap: wrap; gap: var(--space-2);
}
.site-title { font-family: var(--font-serif); font-size: var(--step-1); font-weight: 600; text-decoration: none; color: var(--color-ink); }
.site-title small { display: block; font-family: var(--font-sans); font-size: 0.7rem; font-weight: 400; color: var(--color-ink-muted); letter-spacing: 0.02em; }
nav.primary-nav ul { list-style: none; display: flex; gap: var(--space-3); margin: 0; padding: 0; flex-wrap: wrap; }
nav.primary-nav a { text-decoration: none; font-size: 0.9rem; }
nav.primary-nav a:hover { text-decoration: underline; }

/* Mobile nav toggle — zero-JS checkbox pattern. Works with CSS alone; no script required.
   Above the breakpoint, the checkbox/label are hidden and nav is always visible (unchanged
   desktop behaviour). Below it, nav starts collapsed and the label acts as the toggle button. */
.nav-toggle-checkbox { position: absolute; opacity: 0; pointer-events: none; }
.nav-toggle-label {
  display: none; font-family: var(--font-sans); font-size: 0.85rem; cursor: pointer;
  border: 1px solid var(--color-rule); padding: 0.5em 0.8em; min-height: 24px; align-items: center;
}
.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; }

@media (max-width: 760px) {
  .nav-toggle-label { display: inline-flex; }
  nav.primary-nav { display: none; width: 100%; order: 10; }
  nav.primary-nav ul { flex-direction: column; gap: 0.5em; padding: var(--space-2) 0; }
  .nav-toggle-checkbox:checked ~ nav.primary-nav { display: block; }
  .nav-toggle-checkbox:focus-visible ~ .nav-toggle-label { outline: var(--focus-ring); outline-offset: 2px; }
}

main { max-width: 920px; margin: 0 auto; padding: var(--space-4) var(--space-3); }
.prose { max-width: var(--line-length-max); }
.prose p { margin: 0 0 var(--space-2); }
h1, h2, h3 { font-family: var(--font-serif); line-height: 1.25; }
h1 { font-size: var(--step-3); margin: 0 0 var(--space-2); }
h2 { font-size: var(--step-2); margin: var(--space-4) 0 var(--space-2); border-top: 1px solid var(--color-rule); padding-top: var(--space-3); }
h3 { font-size: var(--step-1); margin: var(--space-3) 0 var(--space-1); }

.doorway-grid { display: grid; gap: var(--space-3); grid-template-columns: 1fr; margin: var(--space-4) 0; }
@media (min-width: 720px) { .doorway-grid { grid-template-columns: repeat(3, 1fr); } }
.doorway {
  border: 1px solid var(--color-rule); padding: var(--space-3); text-decoration: none; color: inherit;
  display: block; font-family: var(--font-sans);
}
.doorway:hover, .doorway:focus-visible { border-color: var(--color-institutional-blue); }
.doorway h3 { font-family: var(--font-serif); margin-top: 0; }
.doorway .door-label { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--color-ink-muted); }

/* Evidence tier badge — never colour alone; always letter + label text */
.evidence-badge {
  display: inline-flex; align-items: center; gap: 0.35em;
  font-family: var(--font-sans); font-size: 0.75rem; font-weight: 600;
  padding: 0.15em 0.55em; border-radius: var(--radius); border: 1px solid;
  text-decoration: none; cursor: pointer; line-height: 1.4;
}
.evidence-badge .tier-letter { font-weight: 800; }
.tier-A { background: var(--tier-a-bg); color: var(--tier-a-fg); border-color: var(--tier-a-border); }
.tier-B { background: var(--tier-b-bg); color: var(--tier-b-fg); border-color: var(--tier-b-border); }
.tier-C { background: var(--tier-c-bg); color: var(--tier-c-fg); border-color: var(--tier-c-border); }
.tier-D { background: var(--tier-d-bg); color: var(--tier-d-fg); border-color: var(--tier-d-border); }
.tier-X { background: var(--tier-x-bg); color: var(--tier-x-fg); border-color: var(--tier-x-border); }

/* EvidenceDrawer — native <details>, works with zero JS */
.evidence-drawer {
  border: 1px solid var(--color-rule); margin: var(--space-2) 0; font-family: var(--font-sans); font-size: 0.9rem;
}
.evidence-drawer summary {
  padding: var(--space-1) var(--space-2); cursor: pointer; display: flex; align-items: center; gap: var(--space-1);
  list-style: none;
}
.evidence-drawer summary::-webkit-details-marker { display: none; }
.evidence-drawer summary::before { content: "▸"; color: var(--color-ink-muted); }
.evidence-drawer[open] summary::before { content: "▾"; }
.evidence-drawer .drawer-body { padding: 0 var(--space-2) var(--space-2); border-top: 1px solid var(--color-rule); }
.evidence-drawer dl { display: grid; grid-template-columns: max-content 1fr; gap: 0.25em var(--space-2); margin: var(--space-1) 0; }
.evidence-drawer dt { color: var(--color-ink-muted); font-size: 0.8rem; }

.family-account-banner {
  background: var(--tier-d-bg); border: 1px solid var(--tier-d-border); color: var(--tier-d-fg);
  font-family: var(--font-sans); font-size: 0.8rem; font-weight: 600; letter-spacing: 0.04em;
  text-transform: uppercase; padding: var(--space-1) var(--space-2); margin-bottom: var(--space-2);
  display: inline-block;
}

.open-question { border-left: 4px solid var(--color-ochre); padding: var(--space-2); margin: var(--space-2) 0; background: rgba(163,92,28,0.05); }
.open-question h3 { margin-top: 0; }

.table-scroll { overflow-x: auto; margin: var(--space-2) 0; -webkit-overflow-scrolling: touch; }
table.data-table { width: 100%; min-width: 32rem; border-collapse: collapse; font-family: var(--font-sans); font-size: 0.85rem; }
table.data-table th, table.data-table td { text-align: left; padding: var(--space-1); border-bottom: 1px solid var(--color-rule); vertical-align: top; }

.cite-block { background: var(--color-rule); background: rgba(0,0,0,0.03); border: 1px solid var(--color-rule); padding: var(--space-2); font-family: var(--font-sans); font-size: 0.82rem; margin-top: var(--space-4); }
.cite-block pre { white-space: pre-wrap; word-break: break-word; margin: 0.3em 0; }

.site-footer { border-top: 1px solid var(--color-rule); padding: var(--space-3); font-size: 0.8rem; color: var(--color-ink-muted); }

.withheld-notice { border: 1px dashed var(--color-rule); padding: var(--space-2); font-family: var(--font-sans); font-size: 0.85rem; color: var(--color-ink-muted); text-align: center; }

/* Researcher View — §36. Reveals claim IDs and metadata more prominently; hidden by default. */
.claim-id-tag { display: none; font-family: var(--font-sans); font-size: 0.7rem; color: var(--color-ink-muted); }
.researcher-mode .claim-id-tag { display: inline; }
.researcher-mode .evidence-drawer { border-color: var(--color-institutional-blue); }
.researcher-mode .prose { max-width: none; }