/* ==========================================================================
   Word Structures — shared public-site styles
   WEB-SLICE-1 preview foundation.

   Visual authority: the Word Structures logo (navy foundation; blue/green/
   yellow/red accents; flat colour; hard edges; generous negative space).
   Deliberately NOT a product dashboard: no gradients, no glassmorphism, no
   decorative glow, no blanket rounded cards.

   Tokens below were derived from building this page, not invented ahead of it.
   ========================================================================== */

/* --- 1. Tokens ----------------------------------------------------------- */

:root {
  /* Surfaces */
  --paper:        #fbfaf7;   /* warm white */
  --paper-sunk:   #f4f2ec;
  --navy:         #12244a;
  --navy-deep:    #0d1a36;

  /* Ink */
  --ink:          #12244a;
  --ink-soft:     #55617a;   /* 5.4:1 on --paper */
  --ink-onDark:   #f2f4f8;
  --ink-onDark-soft: #b9c3d6; /* 7.4:1 on --navy */

  /* Accents — from the logo. Used sparingly and never as the sole signal. */
  --blue:   #1668c9;
  --green:  #16713a;   /* darkened for 4.5:1 white-on-green at small cell sizes */
  --yellow: #f5bf00;
  --red:    #d4141c;

  /* Lines */
  --rule:       #dcd8cd;
  --rule-strong:#12244a;

  /* Type */
  --serif: Georgia, "Iowan Old Style", "Times New Roman", serif;
  --sans:  system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;

  /* Space */
  --space-section: clamp(3.5rem, 9vw, 7rem);
  --wrap:          64rem;
  --wrap-narrow:   42rem;

  /* Motion */
  --ease: cubic-bezier(.2, .6, .3, 1);
  --dur: 160ms;
}

/* --- 2. Base ------------------------------------------------------------- */

*, *::before, *::after { box-sizing: border-box; }

/* Any author `display` rule outranks the UA stylesheet's [hidden] { display:none },
   which would otherwise leave hidden controls visible-but-inert. Keep this above
   every component rule. */
[hidden] { display: none !important; }

html {
  /* Anchor targets clear the sticky header. */
  scroll-padding-top: 6rem;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}

h1, h2, h3 {
  font-family: var(--serif);
  font-weight: 400;
  line-height: 1.15;
  letter-spacing: -0.01em;
  margin: 0 0 0.6em;
}

h2 { font-size: clamp(1.5rem, 3.4vw, 2.1rem); }
h3 { font-size: 1.125rem; }

p { margin: 0 0 1em; }

a { color: var(--blue); text-underline-offset: 0.18em; }
a:hover { text-decoration-thickness: 2px; }

img, svg { max-width: 100%; height: auto; }

/* Focus: one visible treatment everywhere. Never removed. */
:focus-visible {
  outline: 3px solid var(--blue);
  outline-offset: 3px;
  border-radius: 1px;
}

/* --- 3. Utilities -------------------------------------------------------- */

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
  border: 0;
}

.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: clamp(1.25rem, 5vw, 2.5rem);
}
.wrap--narrow { max-width: var(--wrap-narrow); }

.skip-link {
  position: absolute;
  left: 0.75rem;
  top: -100%;
  z-index: 50;
  background: var(--navy);
  color: var(--ink-onDark);
  padding: 0.75rem 1.25rem;
  font-weight: 600;
  text-decoration: none;
}
.skip-link:focus { top: 0.75rem; }

/* --- 4. Preview-only banner (removed at WEB-SWAP-1) ---------------------- */

.preview-banner {
  margin: 0;
  padding: 0.6rem clamp(1.25rem, 5vw, 2.5rem);
  background: var(--paper-sunk);
  border-bottom: 1px solid var(--rule);
  color: var(--ink-soft);
  font-size: 0.8125rem;
  line-height: 1.5;
}
.preview-banner strong { color: var(--ink); }

/* --- 5. Header ----------------------------------------------------------- */

.site-header {
  border-bottom: 1px solid var(--rule);
  background: var(--paper);
}

.site-header__inner {
  max-width: var(--wrap);
  margin-inline: auto;
  padding: 0.875rem clamp(1.25rem, 5vw, 2.5rem);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem 1.5rem;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  color: var(--ink);
  text-decoration: none;
  min-height: 44px;
}

/* Footprint reserved for the authentic Word Structures mark. Footer keeps the
   placeholder box (out of scope for PUBLIC-ACCESS-3); the header uses the
   --logo modifier below once the owner-authored asset is in place. */
.brand__mark {
  width: 1.75rem;
  height: 1.75rem;
  flex: none;
  border: 1px dashed var(--rule);
}

/* The owner-authored Word Structures mark (PUBLIC-ACCESS-3), header only.
   object-fit guards against the asset's slightly non-square canvas
   (653x615) without cropping or distorting it. */
.brand__mark--logo {
  border: none;
  display: block;
  object-fit: contain;
}

.brand__word {
  font-family: var(--sans);
  font-weight: 700;
  font-size: 0.9375rem;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}

/* --- 6. Navigation ------------------------------------------------------- */
/* <details open> in markup: with JavaScript off the list simply stays visible
   and usable. site.js collapses it only at narrow widths. */

.nav__toggle {
  display: none;
  font-family: var(--sans);
  font-size: 0.875rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  padding: 0.625rem 0;
  min-height: 44px;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
}
.nav__toggle::-webkit-details-marker { display: none; }
.nav__toggle::after {
  content: "";
  width: 0.5rem; height: 0.5rem;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg) translate(-2px, -2px);
}
.nav[open] .nav__toggle::after { transform: rotate(225deg) translate(-2px, -2px); }

.nav__list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.5rem;
  margin: 0;
  padding: 0;
}

.nav__list a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--ink);
  font-size: 0.9375rem;
  text-decoration: none;
  border-bottom: 2px solid transparent;
}
.nav__list a:hover,
.nav__list a:focus-visible { border-bottom-color: var(--blue); }

@media (max-width: 47.99em) {
  .site-header__inner { align-items: flex-start; }
  .nav { width: 100%; }
  .nav__toggle { display: flex; }
  .nav__list { flex-direction: column; gap: 0; padding-bottom: 0.5rem; }
  .nav__list a { width: 100%; border-bottom: 1px solid var(--rule); }
}

/* --- 7. Hero ------------------------------------------------------------- */
/* The mathematics is the artwork. The wordmark lives in the header, never
   as the hero headline. */

.hero {
  padding-block: clamp(3rem, 11vw, 8rem) clamp(3rem, 9vw, 6.5rem);
  border-bottom: 1px solid var(--rule);
}

.hero__headline {
  font-size: clamp(2rem, 6.2vw, 3.75rem);
  margin: clamp(2rem, 6vw, 3.5rem) 0 0;
  max-width: 18ch;
}

.hero__bridge {
  margin: clamp(1.75rem, 4vw, 2.5rem) 0 0;
  padding-top: 1.25rem;
  border-top: 2px solid var(--rule-strong);
  display: inline-block;
  font-family: var(--serif);
  font-style: italic;
  font-size: clamp(1.0625rem, 2.2vw, 1.375rem);
  color: var(--ink-soft);
}

/* --- 8. The word component ---------------------------------------------- */
/* Equal units, flat fill, hard edges — the logo's grammar, not its shape.
   Colour is never the only signal: every cell shows its letter. */

.word { margin: 0; }

.word__blocks {
  display: flex;
  align-items: center;
  --cell: clamp(2.75rem, 9vw, 5.25rem);
  --gap: 0.3rem;
}

.half {
  display: flex;
  gap: var(--gap);
}

.cell {
  width: var(--cell);
  height: var(--cell);
  display: grid;
  place-items: center;
  font-family: var(--sans);
  font-weight: 700;
  font-size: calc(var(--cell) * 0.5);
  line-height: 1;
}

.cell--a { background: var(--blue);   color: #fff; }
.cell--b { background: var(--yellow); color: var(--navy); }
.cell--c { background: var(--green);  color: #fff; }

/* The divider carries the "two halves" meaning structurally, not by colour. */
.split {
  width: 2px;
  align-self: stretch;
  min-height: var(--cell);
  background: var(--rule-strong);
  margin-inline: clamp(0.75rem, 2.5vw, 1.5rem);
}

.word--small .word__blocks { --cell: clamp(2rem, 6.5vw, 3.25rem); }

/* --- 9. Sections --------------------------------------------------------- */

.section { padding-block: var(--space-section); }
.section--rule { border-top: 1px solid var(--rule); }

.lede {
  font-size: clamp(1.0625rem, 2vw, 1.1875rem);
  color: var(--ink-soft);
  max-width: 46ch;
}

.tag {
  display: inline-block;
  margin: 0 0 1rem;
  padding: 0.25rem 0.6rem;
  background: var(--paper-sunk);
  border: 1px solid var(--rule);
  color: var(--ink-soft);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.tag--onDark {
  background: transparent;
  border-color: rgba(255,255,255,.35);
  color: var(--ink-onDark-soft);
}

/* --- 10. Reveal ---------------------------------------------------------- */

.reveal { margin-top: clamp(2rem, 5vw, 3rem); }
.reveal__stage { margin-bottom: 1.75rem; }

.reveal__step + .reveal__step { margin-top: 2rem; }

.tally {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem 3rem;
}

.tally__label {
  margin: 0 0 0.35rem;
  font-size: 0.75rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-soft);
}

.tally__counts {
  display: flex;
  gap: 1rem;
  margin: 0;
  font-variant-numeric: tabular-nums;
}

.chip { display: inline-flex; align-items: center; gap: 0.4rem; }
.chip__swatch { width: 0.75rem; height: 0.75rem; flex: none; }
.chip__swatch--a { background: var(--blue); }
.chip__swatch--b { background: var(--yellow); }

.reveal__note {
  margin: 1rem 0 0;
  color: var(--ink-soft);
}

.reveal__name {
  font-family: var(--serif);
  font-size: clamp(1.125rem, 2.4vw, 1.375rem);
  max-width: 44ch;
  margin: 0 0 0.75rem;
}
.reveal__name strong { font-weight: 700; }

/* Steps fade in when revealed; motion is opt-out (see section 14). */
.reveal__step { animation: fade var(--dur) var(--ease) both; }
@keyframes fade { from { opacity: 0; transform: translateY(4px); } }

/* --- 11. Buttons --------------------------------------------------------- */
/* Deliberately not oversized marketing CTAs. */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  margin-top: 2rem;
  padding: 0.65rem 1.4rem;
  background: var(--navy);
  color: var(--ink-onDark);
  border: 2px solid var(--navy);
  font-family: var(--sans);
  font-size: 0.9375rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
}
.btn:hover { background: var(--navy-deep); border-color: var(--navy-deep); }

.btn--onDark {
  background: transparent;
  border-color: var(--yellow);
  color: var(--yellow);
}
.btn--onDark:hover { background: var(--yellow); color: var(--navy); }

/* Focus must stay visible against the navy panel. */
.abelisk :focus-visible { outline-color: var(--yellow); }

/* --- 12. Three ways in --------------------------------------------------- */
/* Columns, not cards. Each carries a 3px accent rule — with a text label
   directly beneath it, so the colour is never doing the work alone. */

.ways {
  list-style: none;
  margin: 2.5rem 0 0;
  padding: 0;
  display: grid;
  gap: 2rem;
  grid-template-columns: repeat(auto-fit, minmax(12.5rem, 1fr));
}

.ways__item { border-top: 3px solid var(--rule-strong); padding-top: 1rem; }
.ways__item--learn   { border-top-color: var(--blue); }
.ways__item--explore { border-top-color: var(--green); }
.ways__item--research{ border-top-color: var(--red); }

.ways__item h3 { margin-bottom: 0.35rem; }
.ways__item h3 a { color: var(--ink); text-decoration-color: var(--rule); }
.ways__item p { margin: 0; color: var(--ink-soft); }

/* --- 13. Placeholders ---------------------------------------------------- */

.placeholder {
  border-left: 3px solid var(--rule);
  padding-left: clamp(1rem, 3vw, 1.75rem);
  color: var(--ink-soft);
}
.placeholder__slots {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  margin: 1.5rem 0 0;
}
.placeholder__slots span {
  padding: 0.3rem 0.65rem;
  background: var(--paper-sunk);
  border: 1px dashed var(--rule);
  font-size: 0.8125rem;
}

.abelisk {
  background: var(--navy);
  color: var(--ink-onDark);
  padding-block: var(--space-section);
}
.abelisk__title {
  font-size: clamp(1.75rem, 5vw, 3rem);
  margin-bottom: 0.5em;
  letter-spacing: 0.02em;
}
.abelisk__title span { color: var(--ink-onDark-soft); }
.abelisk__lede {
  font-size: clamp(1.0625rem, 2vw, 1.1875rem);
  color: var(--ink-onDark-soft);
  max-width: 46ch;
}

.routes {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 2rem;
  margin: 1.75rem 0 0;
  padding: 0;
}
.routes a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--ink);
  text-decoration-color: var(--blue);
  text-decoration-thickness: 2px;
}

/* --- 14. Footer ---------------------------------------------------------- */

.site-footer {
  border-top: 1px solid var(--rule);
  padding-block: clamp(2.5rem, 6vw, 4rem);
  background: var(--paper-sunk);
}
.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem 3rem;
  align-items: flex-start;
  justify-content: space-between;
}

.lockup { display: flex; align-items: flex-start; gap: 0.75rem; }
.brand__mark--footer { width: 2.5rem; height: 2.5rem; }
.lockup__word {
  display: block;
  font-weight: 700;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  font-size: 0.9375rem;
}
.lockup__tagline {
  display: block;
  font-family: var(--serif);
  font-style: italic;
  color: var(--ink-soft);
  margin-top: 0.15rem;
}

.site-footer__links {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 0.25rem 1.75rem;
  margin: 0;
  padding: 0;
}
.site-footer__links a {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--ink);
}

/* --- 15. Question / answer disclosure ------------------------------------ */
/* Native <details>/<summary>: keyboard-operable and readable with JavaScript
   off, with no ARIA and no custom widget. Used by the Learn exercise. */

.qa { margin-top: 2rem; }
.qa h3 { margin-bottom: 0.6rem; font-family: var(--sans); font-size: 1rem; font-weight: 600; }

.qa__word {
  display: inline-block;
  margin-left: 0.35rem;
  padding: 0.15rem 0.5rem;
  background: var(--paper-sunk);
  border: 1px solid var(--rule);
  font-family: var(--sans);
  font-weight: 700;
  letter-spacing: 0.22em;
}

.qa summary {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  gap: 0.5rem;
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--blue);
  cursor: pointer;
}
.qa summary::-webkit-details-marker { display: none; }
.qa summary::before {
  content: "";
  width: 0.5rem; height: 0.5rem;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(-45deg);
}
.qa[open] summary::before,
.qa details[open] summary::before { transform: rotate(45deg); }

.qa__answer {
  border-left: 3px solid var(--rule);
  padding-left: clamp(0.875rem, 2.5vw, 1.25rem);
  margin-top: 0.25rem;
}
.qa__answer p:last-child { margin-bottom: 0; }

/* A quiet pointer to where a statement's evidence lives. */
.source-note {
  margin-top: 2rem;
  padding-top: 1rem;
  border-top: 1px solid var(--rule);
  font-size: 0.9375rem;
  color: var(--ink-soft);
}

/* Current page in the primary navigation — marked by weight and a rule, never
   by colour alone. */
.nav__list a[aria-current="page"] {
  border-bottom-color: var(--ink);
  font-weight: 600;
}

/* Small vertical nudge where a figure follows body copy. */
.stack-top { margin-top: 1.5rem; }

/* --- 16. Evidence ladder (Research) --------------------------------------- */
/* Each row states its status as explicit text in the badge; colour is a
   secondary cue only, never the sole signal (verified/known/open remain
   legible in any colour scheme or with colour vision deficiency). */

.ladder { margin: 2rem 0 0; }
.ladder__row {
  display: grid;
  grid-template-columns: 12rem 1fr;
  gap: 0.5rem 1.5rem;
  padding: 1rem 0;
  border-top: 1px solid var(--rule);
}
.ladder__row:first-child { border-top: none; }
.ladder__row dd { margin: 0; color: var(--ink-soft); }

.status-badge {
  display: inline-block;
  padding: 0.25rem 0.6rem;
  border: 1px solid var(--rule-strong);
  font-family: var(--sans);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  white-space: nowrap;
}
.status-badge--computed { border-color: var(--blue); color: var(--blue); }
.status-badge--known    { border-color: var(--green); color: var(--green); }
.status-badge--open     { border-color: var(--red); color: var(--red); }

@media (max-width: 34.99em) {
  .ladder__row { grid-template-columns: 1fr; }
}

/* --- 17. Research directions and tool groups ------------------------------ */

.directions {
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1.25rem;
}
.directions li { padding-top: 1rem; border-top: 1px solid var(--rule); }
.directions li:first-child { border-top: none; padding-top: 0; }

.tools__group-label {
  margin: 2rem 0 0.75rem;
  font-family: var(--sans);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink-soft);
}
.tools__group-label:first-of-type { margin-top: 1.5rem; }

/* --- 18. Growth sequence (Start Here) -------------------------------------- */
/* A quiet numeric progression, set in tabular figures so the digits align
   without needing a chart or canvas. */

.growth-sequence {
  margin: 1.5rem 0;
  font-family: var(--sans);
  font-variant-numeric: tabular-nums;
  font-size: clamp(1.125rem, 3vw, 1.5rem);
  font-weight: 700;
  color: var(--ink);
  letter-spacing: 0.02em;
}

/* --- 19. Start Here invitation (homepage) ---------------------------------- */
/* A quiet interstitial, not a full section: lighter vertical rhythm than the
   surrounding sections so it reads as an invitation rather than a banner. */

.start-invite { padding-block: clamp(2rem, 5vw, 3rem); }

/* --- 21. Evidence chain (Evidence) ------------------------------------------ */
/* A numbered list, not a diagram: the four stages are meaningful as an order,
   and a native <ol> gives that order to assistive tech for free. */

.chain {
  margin: 2rem 0 0;
  padding-left: 1.4rem;
  display: grid;
  gap: 1.25rem;
}
.chain li { padding-left: 0.4rem; }
.chain strong { display: inline-block; margin-bottom: 0.25rem; }

/* Three more ledger-status badges, following the exact pattern already used
   by .status-badge / .status-badge--computed (research.html's evidence
   ladder). Colour is never the only signal: the status name is always the
   badge's own text. */
.status-badge--primary   { border-color: var(--green);  color: var(--green); }
.status-badge--indirect  { border-color: var(--yellow);  color: #8a6d00; } /* darkened for 4.5:1 on --paper */
.status-badge--rejected  { border-color: var(--red);     color: var(--red); }

/* --- 22. Reduced motion -------------------------------------------------- */

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* --- 23. Explore pathways (Explore) --------------------------------------- */
/* A numbered <ol>, not a card grid: order is meaningful (try, then watch,
   then see, then play), and a plain numeral avoids the per-item "traffic
   light" colour-coding this design system deliberately avoids elsewhere.
   Every item shares the same ink-coloured top rule. */

.pathways {
  list-style: none;
  margin: 2.5rem 0 0;
  padding: 0;
  display: grid;
  gap: 2rem 2.5rem;
  grid-template-columns: repeat(auto-fit, minmax(22rem, 1fr));
}

.pathway { border-top: 2px solid var(--rule-strong); padding-top: 1rem; }

.pathway__num {
  margin: 0 0 0.5rem;
  font-family: var(--sans);
  font-size: 0.75rem;
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.1em;
  color: var(--ink-soft);
}

.pathway__title { margin-bottom: 0.35rem; }
.pathway__title a { color: var(--ink); text-decoration-color: var(--rule); }
.pathway__desc { margin: 0; color: var(--ink-soft); }
.pathway__desc a { color: var(--ink-soft); text-decoration-color: var(--rule); }

/* --- 24. Deeper routes (Explore) ------------------------------------------- */

.deeper-routes {
  display: grid;
  gap: 2.5rem;
  grid-template-columns: repeat(auto-fit, minmax(16rem, 1fr));
  margin-top: 2rem;
}
.deeper-routes h3 { margin-bottom: 0.35rem; }
.deeper-routes p { color: var(--ink-soft); }
.deeper-routes .routes { margin-top: 1rem; }