/*
 * DendroSeal Web Platform V2 — site.css
 *
 * ONE visual system for the public site, Field Link and Case Desk.
 * There is no second design system and no compiled/duplicated stylesheet.
 *
 * Order: tokens → reset → typography → layout → components → surfaces → responsive.
 * The platform ships no JavaScript; interactive disclosure uses <details>.
 */

/* ---------------------------------------------------------------- tokens */
:root {
  --paper: #ffffff;
  --paper-2: #f4f5f6;
  --paper-3: #e9ebed;
  --ink: #11171d;
  --ink-2: #3d474f;
  --ink-3: #6b757d;
  --line: #d8dcdf;
  --line-strong: #b6bcc1;
  --field: #b8271f;
  --field-dark: #8f1c16;
  --internal: #1f3b5c;
  --ok: #1d6b45;

  --font: "Helvetica Neue", Helvetica, Arial, "Segoe UI", system-ui, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --step--1: 0.8125rem;
  --step-0: 1rem;
  --step-1: 1.1875rem;
  --step-2: 1.5rem;
  --step-3: 2rem;
  --step-4: 2.75rem;
  --step-5: 3.5rem;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.5rem;
  --space-6: 2rem;
  --space-7: 3rem;
  --space-8: 4.5rem;
  --space-9: 6rem;

  --shell: 76rem;
  --radius: 3px;
}

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

html { -webkit-text-size-adjust: 100%; }

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

img, video { max-width: 100%; height: auto; display: block; }

a { color: inherit; }

ul, ol { margin: 0; padding: 0; }

h1, h2, h3, p, dl, dd { margin: 0; }

/* ------------------------------------------------------------ typography */
.statement {
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.15;
  text-wrap: balance;
}
.statement--hero { font-size: var(--step-5); }
.statement--page { font-size: var(--step-4); }
.statement--card { font-size: var(--step-1); }
.statement--sm { font-size: var(--step-1); font-weight: 600; }

.page-title { font-size: var(--step-4); font-weight: 700; line-height: 1.15; letter-spacing: -0.01em; }
.section-title { font-size: var(--step-2); font-weight: 700; margin-bottom: var(--space-5); }

.eyebrow {
  font-size: var(--step--1);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-3);
  margin-bottom: var(--space-3);
}

.prose > * + * { margin-top: var(--space-4); }
.prose p { max-width: 62ch; color: var(--ink-2); }

.footnote { font-size: var(--step--1); color: var(--ink-3); max-width: 78ch; margin-top: var(--space-5); }

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

.skip-link {
  position: absolute; left: -9999px; top: 0; background: var(--ink); color: #fff;
  padding: var(--space-3) var(--space-4); z-index: 100;
}
.skip-link:focus { left: 0; }

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

/* ---------------------------------------------------------------- layout */
.shell { width: 100%; max-width: var(--shell); margin: 0 auto; padding: 0 var(--space-5); }

.section { padding: var(--space-7) 0; border-top: 1px solid var(--line); }
.section--accent { background: var(--paper-2); }

.page-head { padding: var(--space-7) 0 var(--space-6); }
.page-head__lede { font-size: var(--step-1); color: var(--ink-2); max-width: 62ch; margin-top: var(--space-4); }
.page-head--internal { border-bottom: 3px solid var(--internal); }

/* ---------------------------------------------------------------- header */
.site-header { border-bottom: 1px solid var(--line); background: var(--paper); }
.site-header__inner {
  display: flex; align-items: center; gap: var(--space-5);
  min-height: 4.25rem; justify-content: space-between;
}

.brand { display: inline-flex; align-items: center; gap: var(--space-3); text-decoration: none; }
/* The approved DendroSeal Icon Master, served as a vector image.
   Logo System & Usage Standard v1.0:
     §8   Master Icon minimum digital size is 32 px. 2rem == 32px at the
          default root size, so this is the floor, not a preference.
     §12  Never redraw the mark in CSS, never rotate or stretch it, and never
          add gradient, glow, shadow, bevel or 3D. Equal width and height plus
          object-fit: contain guarantee the 1:1 master is never distorted.
   Only the box is styled here. The geometry lives in the approved SVG. */
.brand__mark { width: 2rem; height: 2rem; flex: 0 0 auto; display: block; object-fit: contain; }
.brand__word { font-weight: 700; letter-spacing: 0.14em; font-size: var(--step--1); }

.site-nav { display: none; gap: var(--space-5); }
.site-nav__link {
  text-decoration: none; font-size: var(--step--1); letter-spacing: 0.04em;
  color: var(--ink-2); padding: var(--space-2) 0; border-bottom: 2px solid transparent;
}
.site-nav__link:hover { color: var(--ink); }
.site-nav__link.is-active { color: var(--ink); border-bottom-color: var(--field); }

.site-header__action { display: none; }

.mobile-nav { position: relative; }
.mobile-nav__summary {
  cursor: pointer; list-style: none; font-size: var(--step--1); letter-spacing: 0.08em;
  text-transform: uppercase; border: 1px solid var(--line-strong); padding: var(--space-2) var(--space-4);
  border-radius: var(--radius);
}
.mobile-nav__summary::-webkit-details-marker { display: none; }
.mobile-nav__panel {
  position: absolute; right: 0; top: calc(100% + 0.5rem); z-index: 30; min-width: 15rem;
  display: flex; flex-direction: column; background: var(--paper);
  border: 1px solid var(--line); box-shadow: 0 8px 24px rgba(17, 23, 29, 0.12);
}
.mobile-nav__panel a { padding: var(--space-3) var(--space-4); text-decoration: none; border-bottom: 1px solid var(--line); }
.mobile-nav__panel a:last-child { border-bottom: 0; }
.mobile-nav__action { color: var(--field); font-weight: 600; }

/* --------------------------------------------------------------- buttons */
.button {
  display: inline-flex; align-items: center; justify-content: center;
  padding: var(--space-3) var(--space-5);
  font-size: var(--step--1); font-weight: 600; letter-spacing: 0.04em;
  text-decoration: none; border: 1px solid transparent; border-radius: var(--radius);
  background: var(--ink); color: #fff;
}
.button:hover { background: #000; }
.button--field-link { background: var(--field); }
.button--field-link:hover { background: var(--field-dark); }
.button--ghost { background: transparent; color: var(--ink); border-color: var(--line-strong); }
.button--ghost:hover { background: var(--paper-2); }
.button--lg { padding: var(--space-4) var(--space-6); font-size: var(--step-0); }

/* ----------------------------------------------------------------- cards */
.card-grid { display: grid; gap: var(--space-5); grid-template-columns: 1fr; }

.card {
  border: 1px solid var(--line); border-radius: var(--radius); background: var(--paper);
  padding: var(--space-5); display: flex; flex-direction: column; gap: var(--space-3);
}
.card__eyebrow {
  font-size: var(--step--1); text-transform: uppercase; letter-spacing: 0.1em; color: var(--ink-3);
}
.card__title { font-size: var(--step-1); font-weight: 700; }
.card__text { color: var(--ink-2); }
.card__more { font-size: var(--step--1); font-weight: 600; color: var(--field); }
.card__state {
  font-size: var(--step--1); color: var(--ink-3); border-top: 1px solid var(--line);
  padding-top: var(--space-3); margin-top: auto;
}
.card--door { text-decoration: none; }
.card--door:hover { border-color: var(--line-strong); background: var(--paper-2); }
.card--reserved { border-style: dashed; }

/* ------------------------------------------------ technical value blocks */
.value-grid { display: grid; gap: var(--space-4); grid-template-columns: 1fr; }
.value-block {
  border: 1px solid var(--line); border-left: 3px solid var(--field);
  padding: var(--space-4) var(--space-5); background: var(--paper);
}
.value-block__value { font-size: var(--step-3); font-weight: 700; line-height: 1.1; letter-spacing: -0.01em; }
.value-block__label { font-size: var(--step-0); font-weight: 600; margin-top: var(--space-2); }
.value-block__qualifier { font-size: var(--step--1); color: var(--ink-3); margin-top: var(--space-2); }
.value-grid--compact .value-block__value { font-size: var(--step-2); }

.principle {
  margin-top: var(--space-6); padding: var(--space-5);
  background: var(--ink); color: #fff; border-radius: var(--radius);
}
.principle__line { font-family: var(--font-mono); font-size: var(--step-0); }
.principle__line + .principle__line { margin-top: var(--space-3); }
.principle__note { font-size: var(--step--1); color: #c6ccd1; margin-top: var(--space-4); max-width: 70ch; }

.boundary { border: 1px solid var(--line-strong); background: var(--paper-2); padding: var(--space-5); }
.boundary__title { font-weight: 700; margin-bottom: var(--space-3); }
.boundary__note { font-size: var(--step--1); color: var(--ink-2); margin-top: var(--space-3); max-width: 78ch; }

.plain-list { list-style: none; display: flex; flex-direction: column; gap: var(--space-2); }
.plain-list li { padding-left: var(--space-4); position: relative; color: var(--ink-2); }
.plain-list li::before {
  content: ""; position: absolute; left: 0; top: 0.65em; width: 6px; height: 1px; background: var(--line-strong);
}

/* -------------------------------------------------------------- sequence */
.sequence { list-style: none; display: flex; flex-direction: column; gap: var(--space-3); }
.sequence__step {
  display: flex; align-items: center; gap: var(--space-3);
  border: 1px solid var(--line); padding: var(--space-3) var(--space-4); background: var(--paper);
  font-weight: 600;
}
.sequence__index {
  display: inline-flex; align-items: center; justify-content: center;
  width: 1.75rem; height: 1.75rem; flex: 0 0 auto;
  background: var(--ink); color: #fff; font-size: var(--step--1); border-radius: 50%;
}

/* -------------------------------------------------------------- equation */
.equation { border: 1px solid var(--line); padding: var(--space-5); background: var(--paper-2); }
.equation__terms { display: flex; flex-wrap: wrap; align-items: center; gap: var(--space-3); }
.equation__term {
  background: var(--paper); border: 1px solid var(--line-strong);
  padding: var(--space-2) var(--space-4); font-weight: 600;
}
.equation__operator { color: var(--ink-3); font-weight: 700; }
.equation__result { margin-top: var(--space-4); font-size: var(--step-1); font-weight: 700; }
.equation__arrow { color: var(--field); margin-right: var(--space-2); }

/* ------------------------------------------------------ home / field band */
.reality { padding: var(--space-8) 0 var(--space-6); }
.reality__lede { font-size: var(--step-1); color: var(--ink-2); max-width: 60ch; margin-top: var(--space-5); }

.reality-action { padding: var(--space-6) 0 var(--space-8); border-top: 1px solid var(--line); }
.reality-action__title { font-size: var(--step-2); font-weight: 700; }
.reality-action__lede { color: var(--ink-2); max-width: 60ch; margin-top: var(--space-3); }
.reality-action__buttons { display: flex; flex-wrap: wrap; gap: var(--space-4); margin-top: var(--space-5); }

.state-note { font-size: var(--step--1); color: var(--ink-3); margin-top: var(--space-4); }

.field-link-band { background: var(--ink); color: #fff; padding: var(--space-7) 0; }
.field-link-band__inner { display: flex; flex-direction: column; gap: var(--space-5); }
.field-link-band__title { font-size: var(--step-2); font-weight: 700; }
.field-link-band__lede { color: #c6ccd1; max-width: 52ch; margin-top: var(--space-2); }
.field-link-band__actions { display: flex; flex-wrap: wrap; gap: var(--space-4); }
.field-link-band .button--ghost { color: #fff; border-color: rgba(255, 255, 255, 0.4); }
.field-link-band .button--ghost:hover { background: rgba(255, 255, 255, 0.1); }

/* ----------------------------------------------------------- field cases */
.case-grid { display: grid; gap: var(--space-6); grid-template-columns: 1fr; }

.case-card { border: 1px solid var(--line); background: var(--paper); display: flex; flex-direction: column; }
.case-card__media { background: var(--paper-3); }
.case-card__media img, .case-card__media video { width: 100%; object-fit: cover; }
.case-card__body { padding: var(--space-5); display: flex; flex-direction: column; gap: var(--space-3); }
.case-card__stage {
  font-size: var(--step--1); text-transform: uppercase; letter-spacing: 0.1em; color: var(--field); font-weight: 700;
}
.case-card__title { font-size: var(--step-1); font-weight: 700; }
.case-card__title a { text-decoration: none; }
.case-card__title a:hover { text-decoration: underline; }
.case-card__reality { color: var(--ink-2); }
.case-card__result { color: var(--ink-2); }
.case-card__verified { font-weight: 600; }

.fact-list { display: flex; flex-direction: column; border-top: 1px solid var(--line); }
.fact-list__row {
  display: grid; grid-template-columns: 1fr; gap: var(--space-1);
  padding: var(--space-3) 0; border-bottom: 1px solid var(--line);
}
.fact-list__row dt { font-size: var(--step--1); text-transform: uppercase; letter-spacing: 0.08em; color: var(--ink-3); }
.fact-list__row dd { margin: 0; font-weight: 600; }
.fact-list__qualifier { display: block; font-size: var(--step--1); font-weight: 400; color: var(--ink-3); }

.case-detail__reality { font-size: var(--step-1); color: var(--ink-2); max-width: 62ch; }
.case-detail__media { display: grid; gap: var(--space-5); grid-template-columns: 1fr; margin-top: var(--space-5); }
.field-media { margin: 0; border: 1px solid var(--line); background: var(--paper-3); }
.field-media figcaption { font-size: var(--step--1); color: var(--ink-3); padding: var(--space-3) var(--space-4); background: var(--paper); }

.empty-state { border: 1px dashed var(--line-strong); padding: var(--space-6); background: var(--paper-2); }
.empty-state__title { font-weight: 700; margin-bottom: var(--space-3); }
.empty-state p { color: var(--ink-2); max-width: 74ch; }

/* ------------------------------------------------------------ field link */
.state-banner { border-left: 3px solid var(--field); background: var(--paper-2); padding: var(--space-5); }
.state-banner--internal { border-left-color: var(--internal); }
.state-banner__title { font-weight: 700; margin-bottom: var(--space-3); }

.channel-list { display: grid; gap: var(--space-4); grid-template-columns: 1fr; }
.channel { border: 1px solid var(--line); padding: var(--space-4); }
.channel--reserved { border-style: dashed; color: var(--ink-3); }
.channel__name { font-weight: 600; }
.channel__state { font-size: var(--step--1); color: var(--ink-3); margin-top: var(--space-1); }

.trust-layers { list-style: none; display: flex; flex-direction: column; gap: var(--space-3); }
.trust-layers__item { display: flex; align-items: center; gap: var(--space-4); border-bottom: 1px solid var(--line); padding-bottom: var(--space-3); }
.trust-layers__index {
  display: inline-flex; align-items: center; justify-content: center; width: 1.75rem; height: 1.75rem;
  border: 1px solid var(--line-strong); border-radius: 50%; font-size: var(--step--1); flex: 0 0 auto;
}
.trust-layers__label { font-weight: 600; }

/* ------------------------------------------------------------- case desk */
.is-internal .site-header { border-bottom-color: var(--internal); }

.desk-grid { display: grid; gap: var(--space-5); grid-template-columns: 1fr; }
.desk-panel { border: 1px solid var(--line); padding: var(--space-5); background: var(--paper); display: flex; flex-direction: column; gap: var(--space-3); }
.desk-panel__title { font-size: var(--step-1); font-weight: 700; }
.desk-panel__text { color: var(--ink-2); }
.desk-panel__state {
  font-size: var(--step--1); color: var(--ink-3); margin-top: auto;
  border-top: 1px solid var(--line); padding-top: var(--space-3);
}

.signal-list { list-style: none; display: flex; flex-wrap: wrap; gap: var(--space-2); }
.signal {
  font-size: var(--step--1); font-weight: 700; letter-spacing: 0.06em;
  border: 1px solid var(--line-strong); padding: var(--space-1) var(--space-3); border-radius: var(--radius);
  color: var(--ink-3);
}
.signal--cleared { color: var(--ok); border-color: var(--ok); }
.signal--pending { color: var(--field); border-color: var(--field); }

.secondary-details { border: 1px solid var(--line); background: var(--paper-2); }
.secondary-details > summary {
  cursor: pointer; padding: var(--space-4) var(--space-5); font-size: var(--step--1);
  text-transform: uppercase; letter-spacing: 0.08em; color: var(--ink-3);
}
.secondary-details__body { padding: 0 var(--space-5) var(--space-5); }

.tag {
  font-size: 0.6875rem; text-transform: uppercase; letter-spacing: 0.08em;
  border: 1px solid var(--line-strong); padding: 0 var(--space-2); border-radius: var(--radius); color: var(--ink-3);
}
.tag--internal { color: var(--internal); border-color: var(--internal); }

/* ---------------------------------------------------------------- footer */
.site-footer { border-top: 1px solid var(--line); background: var(--paper-2); padding: var(--space-7) 0 var(--space-5); margin-top: var(--space-7); }
.site-footer__inner { display: grid; gap: var(--space-6); grid-template-columns: 1fr; }
.site-footer__group { display: flex; flex-direction: column; gap: var(--space-2); }
.site-footer__group a { font-size: var(--step--1); color: var(--ink-2); text-decoration: none; }
.site-footer__group a:hover { color: var(--ink); text-decoration: underline; }
.site-footer__title { font-size: var(--step--1); text-transform: uppercase; letter-spacing: 0.1em; color: var(--ink-3); font-weight: 600; }
.site-footer__legal { margin-top: var(--space-6); padding-top: var(--space-4); border-top: 1px solid var(--line); }
.site-footer__legal p { font-size: var(--step--1); color: var(--ink-3); max-width: 78ch; }

/* ------------------------------------------------------------ field media */
/* Real Field media only. Nothing here is decorative: if an image is on this
   site it is a Field Reality, a Resulting ISB, a DendroSeal demonstration or
   DendroSeal equipment. Video never autoplays. */
.field-media { margin: 0; border: 1px solid var(--line); background: var(--paper-3); overflow: hidden; }
.field-media__image { display: block; width: 100%; height: auto; }
.field-media__player { display: block; width: 100%; height: auto; aspect-ratio: 16 / 9; background: var(--ink); }
.field-media__fallback { color: #fff; padding: var(--space-4); font-size: var(--step--1); }
.field-media__caption {
  display: flex; flex-direction: column; gap: var(--space-2);
  padding: var(--space-3) var(--space-4); background: var(--paper);
}
.field-media__text { font-size: var(--step--1); color: var(--ink-2); }
.field-media__boundary {
  font-size: var(--step--1); color: var(--ink-3);
  border-left: 3px solid var(--field); padding-left: var(--space-3);
}

/* ------------------------------------------------------ introduction film */
/* One film, centred and capped so it stays readable on a large desktop and
   never overflows a narrow viewport. The player inherits the shared Field
   media player rules; only the frame differs. */
.introduction-film__figure { max-width: 60rem; margin-inline: auto; }
.introduction-film__player { aspect-ratio: 16 / 9; width: 100%; height: auto; }

.media-single { margin-top: var(--space-5); max-width: 56rem; }
.media-feature { display: grid; gap: var(--space-6); grid-template-columns: 1fr; align-items: center; }
.media-feature__body > * + * { margin-top: var(--space-3); }
.media-feature__body p { color: var(--ink-2); max-width: 56ch; }
.fine-print { font-size: var(--step--1); color: var(--ink-3); max-width: 66ch; }

/* ------------------------------------------------------------- field wall */
.field-wall { display: grid; gap: var(--space-4); grid-template-columns: 1fr; margin-top: var(--space-5); }
.field-wall__item {
  position: relative; display: block; overflow: hidden;
  background: var(--ink); text-decoration: none; border: 1px solid var(--line);
}
.field-wall__image { display: block; width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.field-wall__label {
  position: absolute; inset: auto 0 0 0; display: flex; flex-direction: column; gap: 0.15rem;
  padding: var(--space-6) var(--space-4) var(--space-3);
  background: linear-gradient(rgba(0, 0, 0, 0), rgba(0, 0, 0, 0.82)); color: #fff;
}
.field-wall__stage { font-size: var(--step--1); text-transform: uppercase; letter-spacing: 0.1em; font-weight: 700; }
.field-wall__title { font-weight: 600; }
.field-wall__item:hover .field-wall__title { text-decoration: underline; }

.case-card__media { position: relative; display: block; }
.case-card__image { display: block; width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.case-card__play {
  position: absolute; top: var(--space-3); right: var(--space-3);
  background: rgba(0, 0, 0, 0.72); color: #fff; font-size: var(--step--1);
  text-transform: uppercase; letter-spacing: 0.08em; padding: 0.2rem 0.5rem;
}
.case-card__result--absent { color: var(--ink-3); }
.case-card__more { margin-top: auto; padding-top: var(--space-3); font-weight: 600; }

/* ------------------------------------------------------------ responsive */
@media (min-width: 40rem) {
  .field-wall { grid-template-columns: repeat(2, 1fr); }
  .card-grid--2 { grid-template-columns: repeat(2, 1fr); }
  .value-grid { grid-template-columns: repeat(2, 1fr); }
  .channel-list { grid-template-columns: repeat(2, 1fr); }
  .fact-list__row { grid-template-columns: 14rem 1fr; gap: var(--space-4); align-items: baseline; }
  .sequence { flex-direction: row; flex-wrap: wrap; }
  .sequence__step { flex: 1 1 12rem; }
  .site-footer__inner { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 60rem) {
  :root { --step-4: 3.25rem; --step-5: 4.5rem; }
  .site-nav { display: flex; }
  .site-header__action { display: inline-flex; }
  .mobile-nav { display: none; }
  .card-grid--3 { grid-template-columns: repeat(3, 1fr); }
  .card-grid--4 { grid-template-columns: repeat(4, 1fr); }
  .value-grid { grid-template-columns: repeat(4, 1fr); }
  .value-grid--compact { grid-template-columns: repeat(4, 1fr); }
  .case-grid { grid-template-columns: repeat(2, 1fr); }
  .case-detail__media { grid-template-columns: repeat(2, 1fr); }
  .field-wall { grid-template-columns: repeat(3, 1fr); }
  .media-feature { grid-template-columns: repeat(2, 1fr); }
  .channel-list { grid-template-columns: repeat(3, 1fr); }
  .desk-grid { grid-template-columns: repeat(2, 1fr); }
  .desk-panel--wide { grid-column: 1 / -1; }
  .field-link-band__inner { flex-direction: row; align-items: center; justify-content: space-between; }
  .site-footer__inner { grid-template-columns: 1.5fr 1fr 1fr 1fr; }
  .section { padding: var(--space-8) 0; }
}

@media (prefers-reduced-motion: reduce) {
  * { animation: none !important; transition: none !important; }
}

@media print {
  .site-header, .site-footer, .field-link-band, .skip-link { display: none; }
  body { color: #000; }
}