/* ==========================================================================
   DIGIHELIX DESIGN SYSTEM — LAYER 2: BASE + COMPONENTS
   Requires tokens.css. Every value below is a token; no raw hex, no magic px.
   ========================================================================== */

/* --------------------------------------------------------------------------
   1.0  RESET + BASE
   -------------------------------------------------------------------------- */

*, *::before, *::after { box-sizing: border-box; }
[hidden] { display: none !important; }

html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

body {
  margin: 0;
  background: var(--dh-bg);
  color: var(--dh-ink);
  font-family: var(--dh-font-sans);
  font-size: var(--dh-text-body);
  font-weight: var(--dh-weight-regular);
  line-height: var(--dh-leading-body);
  letter-spacing: var(--dh-track-body);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-wrap: break-word;
}

img, svg { display: block; max-width: 100%; }

h1, h2, h3, h4 {
  margin: 0;
  font-weight: var(--dh-weight-bold);
  line-height: var(--dh-leading-snug);
  letter-spacing: var(--dh-track-title);
  text-wrap: balance;
}
p, ul, ol { margin: 0; }
ul, ol { padding-left: 1.15em; }
li + li { margin-top: var(--dh-space-2); }

a { color: inherit; }

:focus-visible {
  outline: 2px solid var(--dh-focus);
  outline-offset: 3px;
}
.dh-inverse :focus-visible { outline-color: var(--dh-focus-inverse); }

::selection { background: var(--dh-blue-20); color: var(--dh-ink); }

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

.dh-skip-link {
  position: absolute; left: var(--dh-space-4); top: var(--dh-space-4);
  z-index: 100; transform: translateY(-200%);
  background: var(--dh-ink); color: var(--dh-ink-inverse);
  padding: var(--dh-space-3) var(--dh-space-4);
  text-decoration: none; font-weight: var(--dh-weight-bold);
}
.dh-skip-link:focus { transform: none; }

/* --------------------------------------------------------------------------
   2.0  LAYOUT PRIMITIVES
   -------------------------------------------------------------------------- */

.dh-container {
  width: 100%;
  max-width: var(--dh-container);
  margin-inline: auto;
  padding-inline: var(--dh-gutter);
}
.dh-container--narrow { max-width: var(--dh-container-narrow); }

.dh-section { padding-block: var(--dh-section-y); }
.dh-section--tight { padding-block: clamp(2.5rem, 5vw, 4rem); }
.dh-section--continue { padding-top: 0; }

/* The header is sticky at 4.5rem — without this, every nav link scrolls its
   target flush to the viewport top, hidden underneath the header row. */
section[id], main[id], #results { scroll-margin-top: calc(var(--dh-header-height) + var(--dh-space-4)); }

.dh-surface        { background: var(--dh-bg-subtle); }
.dh-inverse        { background: var(--dh-bg-inverse); color: var(--dh-ink-inverse); }
.dh-inverse a      { color: var(--dh-ink-inverse); }
.dh-inverse .dh-eyebrow { color: var(--dh-accent-on-dark); }
.dh-inverse .dh-muted   { color: var(--dh-ink-inverse-muted); }

/* Any muted copy inside a dark section must lighten — black-70 on blacky is
   1.9:1 and effectively invisible. One rule, so no component can forget it. */
.dh-inverse .dh-card__body,
.dh-inverse .dh-step p,
.dh-inverse .dh-person p,
.dh-inverse .dh-stat__label,
.dh-inverse .dh-meta dt,
.dh-inverse .dh-back,
.dh-inverse .dh-nav a:not(.dh-btn) { color: var(--dh-ink-inverse-muted); }

.dh-stack > * + * { margin-top: var(--dh-space-4); }
.dh-stack-lg > * + * { margin-top: var(--dh-space-6); }

.dh-grid { display: grid; gap: var(--dh-space-6); }
@media (min-width: 46rem) {
  .dh-grid--2 { grid-template-columns: repeat(2, 1fr); }
  .dh-grid--3 { grid-template-columns: repeat(3, 1fr); }
  .dh-grid--4 { grid-template-columns: repeat(2, 1fr); }
}
@media (min-width: 64rem) {
  .dh-grid--4 { grid-template-columns: repeat(4, 1fr); }
}

/* Brandbook two-column page: numbered label rail + content.
   Holds the section heading and its intro only — wide content (card grids,
   step rows) sits in a full-width block below, or it gets crushed. */
.dh-rail { display: grid; gap: var(--dh-space-5); }
@media (min-width: 60rem) {
  .dh-rail {
    grid-template-columns: minmax(11rem, 1fr) minmax(0, 2.4fr);
    gap: var(--dh-space-8);
  }
  .dh-rail > :last-child {
    border-left: 1px solid var(--dh-rule);
    padding-left: var(--dh-space-8);
  }
  .dh-inverse .dh-rail > :last-child { border-left-color: var(--dh-rule-inverse); }
}

/* Full-width content block that follows a .dh-rail heading */
.dh-block { margin-top: var(--dh-space-8); }

/* --------------------------------------------------------------------------
   3.0  TYPOGRAPHY COMPONENTS
   -------------------------------------------------------------------------- */

.dh-display {
  font-size: var(--dh-text-display);
  line-height: var(--dh-leading-tight);
  letter-spacing: var(--dh-track-display);
  text-transform: uppercase;
}
.dh-h1 { font-size: var(--dh-text-h1); }
.dh-h2 { font-size: var(--dh-text-h2); }
.dh-h3 { font-size: var(--dh-text-h3); }

.dh-eyebrow {
  display: block;
  font-size: var(--dh-text-label);
  font-weight: var(--dh-weight-bold);
  letter-spacing: var(--dh-track-label);
  text-transform: uppercase;
  color: var(--dh-accent);
  margin-bottom: var(--dh-space-3);
}

.dh-lead {
  font-size: var(--dh-text-lead);
  line-height: 1.55;
  color: var(--dh-ink-muted);
  max-width: 46ch;
}
:is(h1, h2, .dh-h1, .dh-h2) + .dh-lead { margin-top: var(--dh-space-5); }
.dh-inverse .dh-lead { color: var(--dh-ink-inverse-muted); }

.dh-muted { color: var(--dh-ink-muted); }
.dh-small { font-size: var(--dh-text-small); }
.dh-measure { max-width: 68ch; }

/* Section number, e.g. "1.0" — lifted straight from the brandbook rail */
.dh-index {
  font-size: var(--dh-text-label);
  font-weight: var(--dh-weight-bold);
  letter-spacing: var(--dh-track-label);
  color: var(--dh-ink-muted);
}
.dh-inverse .dh-index { color: var(--dh-ink-inverse-muted); }

.dh-rule-top {
  border-top: 1px solid var(--dh-rule);
  padding-top: var(--dh-space-5);
}
.dh-inverse .dh-rule-top { border-top-color: var(--dh-rule-inverse); }

/* --------------------------------------------------------------------------
   4.0  LOGO
   The mark is purely typographic (brandbook §1.0): two stacked lines,
   Bold, tight leading. Never stretch, tilt, recolour or overlap it.
   -------------------------------------------------------------------------- */

.dh-logo {
  display: inline-block;
  min-width: var(--dh-logo-min-width);
  font-weight: var(--dh-weight-bold);
  font-size: var(--dh-logo-size, 1.125rem);
  line-height: 0.92;
  letter-spacing: 0.005em;
  text-transform: uppercase;
  text-decoration: none;
  color: currentColor;
  white-space: nowrap;
}
.dh-logo span { display: block; }
.dh-logo--accent { color: var(--dh-accent); }
.dh-logo--lg { --dh-logo-size: clamp(2.5rem, 6vw, 4rem); }

.dh-tagline {
  font-size: var(--dh-text-small);
  font-weight: var(--dh-weight-bold);
  line-height: 1.25;
  letter-spacing: var(--dh-track-title);
  margin-top: var(--dh-space-2);
}

/* --------------------------------------------------------------------------
   5.0  BUTTONS
   -------------------------------------------------------------------------- */

.dh-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--dh-space-2);
  padding: var(--dh-space-3) var(--dh-space-5);
  border: 1px solid transparent;
  border-radius: var(--dh-radius-0);
  font: inherit;
  font-size: var(--dh-text-small);
  font-weight: var(--dh-weight-bold);
  letter-spacing: var(--dh-track-title);
  text-decoration: none;
  cursor: pointer;
  transition: background var(--dh-duration) var(--dh-ease),
              color var(--dh-duration) var(--dh-ease),
              border-color var(--dh-duration) var(--dh-ease);
}
.dh-btn--primary {
  background: var(--dh-accent);
  color: var(--dh-white);
}
.dh-btn--primary:hover { background: var(--dh-accent-hover); }

.dh-btn--ghost {
  background: transparent;
  color: var(--dh-ink);
  border-color: var(--dh-rule-strong);
}
.dh-btn--ghost:hover { background: var(--dh-ink); color: var(--dh-ink-inverse); }

.dh-inverse .dh-btn--ghost { color: var(--dh-ink-inverse); border-color: var(--dh-rule-inverse); }
.dh-inverse .dh-btn--ghost:hover { background: var(--dh-white); color: var(--dh-ink); }

.dh-btn-row { display: flex; flex-wrap: wrap; gap: var(--dh-space-3); }

/* Text link with the brand underline */
.dh-link {
  color: var(--dh-accent);
  font-weight: var(--dh-weight-bold);
  text-decoration: none;
  border-bottom: 2px solid var(--dh-blue-30);
  padding-bottom: 1px;
  transition: border-color var(--dh-duration) var(--dh-ease);
}
.dh-link:hover { border-bottom-color: var(--dh-accent); }
.dh-inverse .dh-link { color: var(--dh-accent-on-dark); border-bottom-color: var(--dh-rule-inverse); }
.dh-inverse .dh-link:hover { border-bottom-color: var(--dh-accent-on-dark); }

/* --------------------------------------------------------------------------
   6.0  HEADER / NAV
   -------------------------------------------------------------------------- */

.dh-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  -webkit-backdrop-filter: saturate(180%) blur(10px);
  backdrop-filter: saturate(180%) blur(10px);
  border-bottom: 1px solid var(--dh-rule);
}
.dh-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--dh-space-5);
  min-height: var(--dh-header-height);
}
.dh-nav { display: none; gap: var(--dh-space-5); align-items: center; }
@media (min-width: 56rem) { .dh-nav { display: flex; } }

/* :not(.dh-btn) matters — a bare `.dh-nav a` outranks `.dh-btn--primary`
   (0-1-1 vs 0-1-0) and would repaint the button label muted grey on blue. */
.dh-nav a:not(.dh-btn) {
  font-size: var(--dh-text-small);
  font-weight: var(--dh-weight-semi);
  text-decoration: none;
  color: var(--dh-ink-muted);
  transition: color var(--dh-duration) var(--dh-ease);
}
.dh-nav a:not(.dh-btn):hover { color: var(--dh-ink); }

.dh-menu { display: block; }
@media (min-width: 56rem) { .dh-menu { display: none; } }

.dh-menu__trigger {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--dh-space-3);
  min-height: var(--dh-space-7);
  padding-inline: var(--dh-space-2);
  margin-right: calc(-1 * var(--dh-space-2));
  font-size: var(--dh-text-small);
  font-weight: var(--dh-weight-semi);
  cursor: pointer;
  list-style: none;
  transition: background var(--dh-duration) var(--dh-ease);
}
.dh-menu__trigger::-webkit-details-marker { display: none; }
.dh-menu__trigger:hover { background: var(--dh-bg-subtle); }
.dh-menu__icon { width: 1.25rem; height: 1.25rem; }
.dh-menu__close { display: none; }
.dh-menu[open] .dh-menu__open { display: none; }
.dh-menu[open] .dh-menu__close { display: block; }

@media (max-width: 55.999rem) {
  body:has(.dh-menu[data-enhanced][open])::before {
    content: "";
    position: fixed;
    inset: var(--dh-header-height) 0 0;
    z-index: 40;
    background: var(--dh-scrim);
  }
}

.dh-menu__panel {
  position: absolute;
  inset-inline: 0;
  top: 100%;
  max-height: calc(100vh - var(--dh-header-height) - 1px);
  max-height: calc(100dvh - var(--dh-header-height) - 1px);
  overflow-y: auto;
  overscroll-behavior: contain;
  scroll-padding-block: var(--dh-space-4);
  background: var(--dh-bg);
  border-bottom: 1px solid var(--dh-rule);
  box-shadow: var(--dh-shadow-1);
  padding: var(--dh-space-4) var(--dh-gutter) var(--dh-space-6);
}
.dh-menu__panel a:not(.dh-btn) {
  display: block;
  padding: var(--dh-space-3) 0;
  font-size: var(--dh-text-lead);
  font-weight: var(--dh-weight-semi);
  text-decoration: none;
  color: var(--dh-ink);
}
.dh-menu__panel a:not(.dh-btn):hover { color: var(--dh-accent); }
.dh-menu__panel .dh-btn {
  justify-content: center;
  margin-top: var(--dh-space-4);
}

/* --------------------------------------------------------------------------
   7.0  HERO
   Dark field with a faint particle grid — an echo of the brandbook cover,
   kept low-contrast so the wordmark never sits on a busy image (§1.9).
   -------------------------------------------------------------------------- */

.dh-hero {
  position: relative;
  overflow: hidden;
  padding-block: clamp(3rem, 7vw, 6rem);
}
.dh-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image: radial-gradient(var(--dh-blue-100) 1px, transparent 1.2px);
  background-size: 22px 22px;
  opacity: 0.5;
  mask-image: radial-gradient(120% 90% at 78% 100%, #000 0%, transparent 68%);
  -webkit-mask-image: radial-gradient(120% 90% at 78% 100%, #000 0%, transparent 68%);
  pointer-events: none;
}
.dh-hero > * { position: relative; }

.dh-hero__title { max-width: 22ch; }
.dh-hero__title span { display: block; }
.dh-hero__lead { max-width: 52ch; margin-top: var(--dh-space-5); }
.dh-hero__stats { margin-top: var(--dh-space-7); }
.dh-stat--link { display: block; text-decoration: none; }
.dh-stat--link:hover .dh-stat__label { text-decoration: underline; text-underline-offset: var(--dh-space-1); }
.dh-stat__detail { display: block; margin-top: var(--dh-space-2); font-size: var(--dh-text-label); }
.dh-case-summary { margin-top: var(--dh-space-5); color: var(--dh-accent); font-weight: var(--dh-weight-semi); }
.dh-contact-status { min-height: 1.65em; margin-top: var(--dh-space-2); }

/* --------------------------------------------------------------------------
   8.0  STAT / METRIC
   -------------------------------------------------------------------------- */

.dh-stats {
  display: grid;
  gap: var(--dh-space-5);
  grid-template-columns: repeat(auto-fit, minmax(11rem, 1fr));
}
.dh-stat { border-top: 1px solid var(--dh-rule); padding-top: var(--dh-space-4); }
.dh-inverse .dh-stat { border-top-color: var(--dh-rule-inverse); }

.dh-stat__value {
  display: block;
  font-size: clamp(1.75rem, 3.4vw, 2.5rem);
  font-weight: var(--dh-weight-bold);
  line-height: 1.05;
  letter-spacing: var(--dh-track-display);
  color: var(--dh-accent);
}
.dh-inverse .dh-stat__value { color: var(--dh-accent-on-dark); }

.dh-stat__label {
  display: block;
  margin-top: var(--dh-space-2);
  font-size: var(--dh-text-small);
  color: var(--dh-ink-muted);
}
.dh-inverse .dh-stat__label { color: var(--dh-ink-inverse-muted); }

/* --------------------------------------------------------------------------
   9.0  CARD
   -------------------------------------------------------------------------- */

.dh-card {
  display: flex;
  flex-direction: column;
  gap: var(--dh-space-3);
  padding: var(--dh-space-6);
  background: var(--dh-white);
  border: 1px solid var(--dh-rule);
  height: 100%;
}
.dh-card__num {
  font-size: var(--dh-text-label);
  font-weight: var(--dh-weight-bold);
  letter-spacing: var(--dh-track-label);
  color: var(--dh-accent);
}
.dh-card__body { color: var(--dh-ink-muted); }
.dh-card__foot { margin-top: auto; padding-top: var(--dh-space-4); }

/* Case card — the whole tile is the link target */
.dh-case {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: var(--dh-space-3);
  padding: var(--dh-space-6);
  border: 1px solid var(--dh-rule);
  background: var(--dh-white);
  height: 100%;
  transition: border-color var(--dh-duration) var(--dh-ease),
              box-shadow var(--dh-duration) var(--dh-ease),
              transform var(--dh-duration) var(--dh-ease);
}
.dh-case:hover { border-color: var(--dh-accent); box-shadow: var(--dh-shadow-1); transform: translateY(-2px); }
.dh-case__title a { text-decoration: none; }
.dh-case__title a::after { content: ""; position: absolute; inset: 0; }
.dh-case__metric {
  margin-top: auto;
  padding-top: var(--dh-space-4);
  border-top: 1px solid var(--dh-rule);
  font-weight: var(--dh-weight-bold);
  color: var(--dh-accent);
}

/* --------------------------------------------------------------------------
   10.0  PHASE STEPS
   -------------------------------------------------------------------------- */

.dh-steps { counter-reset: step -1; display: grid; gap: var(--dh-space-6); }
@media (min-width: 46rem) { .dh-steps { grid-template-columns: repeat(2, 1fr); } }
@media (min-width: 64rem) { .dh-steps { grid-template-columns: repeat(4, 1fr); } }

.dh-step { border-top: 2px solid var(--dh-accent); padding-top: var(--dh-space-4); }
.dh-step::before {
  counter-increment: step;
  content: "0" counter(step);
  display: block;
  font-size: var(--dh-text-label);
  font-weight: var(--dh-weight-bold);
  letter-spacing: var(--dh-track-label);
  color: var(--dh-accent);
  margin-bottom: var(--dh-space-2);
}
.dh-step p { color: var(--dh-ink-muted); margin-top: var(--dh-space-2); }
.dh-inverse .dh-step { border-top-color: var(--dh-accent-on-dark); }
.dh-inverse .dh-step::before { color: var(--dh-accent-on-dark); }

/* --------------------------------------------------------------------------
   11.0  TAGS
   -------------------------------------------------------------------------- */

.dh-tags { display: flex; flex-wrap: wrap; gap: var(--dh-space-2); list-style: none; padding: 0; }
.dh-tags li { margin: 0; }
.dh-tag {
  display: inline-block;
  padding: var(--dh-space-2) var(--dh-space-4);
  border: 1px solid var(--dh-rule);
  border-radius: var(--dh-radius-pill);
  font-size: var(--dh-text-small);
  color: var(--dh-ink-muted);
}
.dh-inverse .dh-tag { border-color: var(--dh-rule-inverse); color: var(--dh-ink-inverse-muted); }

/* --------------------------------------------------------------------------
   12.0  DEFINITION ROW (case-study meta)
   -------------------------------------------------------------------------- */

.dh-meta {
  display: grid;
  gap: var(--dh-space-5);
  grid-template-columns: repeat(auto-fit, minmax(10rem, 1fr));
  margin: 0;
  padding-block: var(--dh-space-5);
  border-block: 1px solid var(--dh-rule);
}
.dh-meta dt {
  font-size: var(--dh-text-label);
  font-weight: var(--dh-weight-bold);
  letter-spacing: var(--dh-track-label);
  text-transform: uppercase;
  color: var(--dh-ink-muted);
}
.dh-meta dd { margin: var(--dh-space-2) 0 0; font-weight: var(--dh-weight-semi); }

/* --------------------------------------------------------------------------
   13.0  TEAM
   -------------------------------------------------------------------------- */

.dh-person__name { font-weight: var(--dh-weight-bold); }
.dh-person__role {
  font-size: var(--dh-text-small);
  font-weight: var(--dh-weight-bold);
  color: var(--dh-accent);
  letter-spacing: var(--dh-track-title);
}
.dh-person p { margin-top: var(--dh-space-3); color: var(--dh-ink-muted); }

/* --------------------------------------------------------------------------
   14.0  FOOTER
   -------------------------------------------------------------------------- */

.dh-footer { border-top: 1px solid var(--dh-rule-inverse); }
.dh-footer__inner {
  display: flex;
  flex-wrap: wrap;
  gap: var(--dh-space-5);
  justify-content: space-between;
  align-items: flex-end;
  padding-block: var(--dh-space-7);
}
.dh-footer__legal { font-size: var(--dh-text-small); color: var(--dh-ink-inverse-muted); }

/* --------------------------------------------------------------------------
   15.0  BACK LINK
   -------------------------------------------------------------------------- */

.dh-back {
  display: inline-block;
  font-size: var(--dh-text-small);
  font-weight: var(--dh-weight-bold);
  letter-spacing: var(--dh-track-title);
  text-decoration: none;
  color: var(--dh-ink-muted);
  margin-bottom: var(--dh-space-5);
}
.dh-back:hover { color: var(--dh-accent); }

.dh-space-top-3 { margin-top: var(--dh-space-3); }
.dh-space-top-4,
.dh-lead.dh-space-top-4 { margin-top: var(--dh-space-4); }
.dh-space-top-5 { margin-top: var(--dh-space-5); }
.dh-space-top-6 { margin-top: var(--dh-space-6); }
.dh-measure-wide { max-width: 60ch; }
.dh-measure-contact { max-width: 55ch; }
.dh-measure-full { max-width: none; }
.dh-text-inverse { color: var(--dh-ink-inverse); }

.dh-error-page {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}
.dh-error-page main { flex: 1; display: grid; align-items: center; }

/* --------------------------------------------------------------------------
   16.0  PRINT
   -------------------------------------------------------------------------- */

@media print {
  .dh-header, .dh-btn-row, .dh-footer { display: none; }
  .dh-inverse { background: #fff !important; color: #000 !important; }
  a[href^="http"]::after { content: " (" attr(href) ")"; font-size: 0.8em; }
}