/* ==========================================================================
   Durability Solutions AI — design system
   Dark navy / graphite / muted steel-blue. Understated, technical, no
   gradients-as-decoration, no stock SaaS chrome.
   ========================================================================== */

:root {
  /* Core palette */
  --navy-950: #060a12;
  --navy-900: #0a0f1a;
  --navy-850: #0d1421;
  --navy-800: #121b2b;
  --navy-700: #182339;

  --graphite-900: #14171c;
  --graphite-700: #2a2f38;
  --graphite-500: #4a505b;
  --graphite-300: #8b919c;

  --steel-300: #9db4cc;
  --steel-400: #7396b8;
  --steel-500: #4c7196;
  --steel-600: #3a5a7a;
  --steel-700: #2c4560;

  --ink: #12161f;
  --ink-muted: #545b66;
  --ink-faint: #8a909b;

  --paper: #f7f8fa;
  --paper-dim: #eef1f4;
  --white: #ffffff;

  --line: #e1e5eb;
  --line-soft: #ebeef2;
  --line-on-dark: rgba(255, 255, 255, 0.10);
  --line-on-dark-strong: rgba(255, 255, 255, 0.16);

  /* Type */
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;

  /* Rhythm */
  --radius: 2px;
  --container-max: 1240px;
  --shadow-card: 0 1px 2px rgba(10, 15, 26, 0.06), 0 8px 24px rgba(10, 15, 26, 0.04);
}

* { box-sizing: border-box; }

html { font-size: 16px; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  font-family: var(--font-sans);
  color: var(--ink);
  background: var(--white);
  line-height: 1.6;
  font-size: 1rem;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  font-family: var(--font-sans);
  font-weight: 600;
  letter-spacing: -0.015em;
  line-height: 1.15;
  margin: 0 0 0.6em;
  color: var(--ink);
}

h1 { font-weight: 650; }

p { margin: 0 0 1em; color: var(--ink-muted); }

a { color: var(--steel-600); text-decoration: none; }
a:hover { color: var(--steel-700); }

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

::selection { background: var(--steel-400); color: var(--white); }

.container { max-width: var(--container-max); margin: 0 auto; padding: 0 1.5rem; }

@media (min-width: 992px) {
  .container { padding: 0 2.5rem; }
}

/* ------------------------------------------------------------------------
   Type scale
   ------------------------------------------------------------------------ */

.display-1 { font-size: clamp(2.4rem, 4.4vw, 3.75rem); letter-spacing: -0.02em; font-weight: 650; }
.display-2 { font-size: clamp(1.9rem, 3.2vw, 2.75rem); letter-spacing: -0.02em; font-weight: 650; }
.h-section { font-size: clamp(1.5rem, 2.1vw, 1.9rem); font-weight: 600; }
.lede { font-size: 1.2rem; line-height: 1.65; color: var(--ink-muted); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--steel-400);
  margin-bottom: 1rem;
}

.eyebrow::before {
  content: "";
  width: 22px;
  height: 1px;
  background: var(--steel-400);
  display: inline-block;
}

.eyebrow.on-light { color: var(--steel-600); }
.eyebrow.on-light::before { background: var(--steel-600); }

/* ------------------------------------------------------------------------
   Technical background textures — subtle, no imagery
   ------------------------------------------------------------------------ */

.tex-grid-dark {
  background-color: var(--navy-900);
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.045) 1px, transparent 1px);
  background-size: 56px 56px;
  background-position: center top;
}

.tex-dots-light {
  background-image: radial-gradient(rgba(18, 22, 31, 0.09) 1px, transparent 1px);
  background-size: 22px 22px;
}

.tex-fade-bottom {
  position: relative;
}
.tex-fade-bottom::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: 0;
  height: 40%;
  background: linear-gradient(to bottom, transparent, var(--navy-900) 92%);
  pointer-events: none;
}

/* ------------------------------------------------------------------------
   Header / navigation
   ------------------------------------------------------------------------ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: rgba(10, 15, 26, 0.92);
  backdrop-filter: saturate(140%) blur(10px);
  border-bottom: 1px solid var(--line-on-dark);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 76px;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  font-family: var(--font-sans);
  font-weight: 650;
  font-size: 1.02rem;
  letter-spacing: 0.01em;
  color: var(--white);
}
.brand:hover { color: var(--white); }
.brand .brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border: 1px solid var(--steel-400);
  color: var(--steel-300);
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0;
}
.brand .brand-full { white-space: nowrap; }
.brand .brand-full .brand-sub { color: var(--steel-300); font-weight: 500; }

.main-nav {
  display: flex;
  align-items: center;
  gap: 2.1rem;
}

.main-nav .nav-link {
  font-size: 0.9rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.72);
  padding: 0.4rem 0;
  border-bottom: 1px solid transparent;
  white-space: nowrap;
}
.main-nav .nav-link:hover { color: var(--white); }
.main-nav .nav-link.active {
  color: var(--white);
  border-bottom-color: var(--steel-400);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--navy-900);
  background: var(--steel-300);
  padding: 0.6rem 1.05rem;
  border: 1px solid var(--steel-300);
  white-space: nowrap;
}
.nav-cta:hover { background: var(--white); border-color: var(--white); color: var(--navy-900); }

.nav-toggle {
  display: none;
  background: none;
  border: 1px solid var(--line-on-dark-strong);
  color: var(--white);
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
}

@media (max-width: 991.98px) {
  .main-nav { display: none; }
  .nav-cta.desktop-only { display: none; }
  .nav-toggle { display: inline-flex; }

  .main-nav.open {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 0;
    position: absolute;
    top: 76px;
    left: 0; right: 0;
    background: var(--navy-900);
    border-bottom: 1px solid var(--line-on-dark);
    padding: 0.5rem 1.5rem 1.5rem;
  }
  .main-nav.open .nav-link {
    width: 100%;
    padding: 0.85rem 0;
    border-bottom: 1px solid var(--line-on-dark);
  }
  .main-nav.open .nav-cta {
    margin-top: 1rem;
    justify-content: center;
    width: 100%;
  }
}

/* ------------------------------------------------------------------------
   Hero
   ------------------------------------------------------------------------ */

.hero {
  position: relative;
  color: var(--white);
  padding: 6.5rem 0 7rem;
  overflow: hidden;
}

.hero .eyebrow { color: var(--steel-300); }
.hero .eyebrow::before { background: var(--steel-300); }

.hero h1 {
  color: var(--white);
  max-width: 780px;
}

.hero .lede {
  color: rgba(255, 255, 255, 0.68);
  max-width: 620px;
  margin-bottom: 2.2rem;
}

.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; }

.hero-graphic {
  position: absolute;
  top: 0; right: -4%;
  width: 46%;
  height: 100%;
  opacity: 0.55;
  pointer-events: none;
}

@media (max-width: 767.98px) {
  .hero { padding: 4.5rem 0 4rem; }
  .hero-graphic { display: none; }
}

/* Page header (secondary pages) */
.page-header {
  position: relative;
  color: var(--white);
  padding: 4.4rem 0 4.6rem;
}
.page-header h1 { color: var(--white); max-width: 760px; }
.page-header .lede { color: rgba(255, 255, 255, 0.68); max-width: 640px; margin: 0; }

.breadcrumb-line {
  display: flex;
  gap: 0.5rem;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  color: var(--steel-300);
  margin-bottom: 1.6rem;
}
.breadcrumb-line a { color: var(--steel-300); }
.breadcrumb-line a:hover { color: var(--white); }
.breadcrumb-line span { color: var(--ink-faint); }

/* ------------------------------------------------------------------------
   Buttons
   ------------------------------------------------------------------------ */

.btn-solid, .btn-outline-line, .btn-ghost {
  display: inline-flex;
  align-items: center;
  gap: 0.55rem;
  font-size: 0.9rem;
  font-weight: 600;
  padding: 0.85rem 1.5rem;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
  transition: background-color 120ms ease, border-color 120ms ease, color 120ms ease;
}

.btn-solid {
  background: var(--steel-300);
  border-color: var(--steel-300);
  color: var(--navy-900);
}
.btn-solid:hover { background: var(--white); border-color: var(--white); color: var(--navy-900); }

.btn-outline-line {
  background: transparent;
  border-color: var(--line-on-dark-strong);
  color: var(--white);
}
.btn-outline-line:hover { border-color: var(--white); color: var(--white); }

.btn-ghost {
  background: transparent;
  border-color: var(--steel-600);
  color: var(--steel-700);
  padding: 0.75rem 1.3rem;
}
.btn-ghost:hover { border-color: var(--steel-700); background: var(--paper-dim); color: var(--steel-700); }

.btn-arrow { transition: transform 120ms ease; }
a:hover .btn-arrow, button:hover .btn-arrow { transform: translateX(3px); }

/* ------------------------------------------------------------------------
   Sections / layout primitives
   ------------------------------------------------------------------------ */

.section { padding: 5.5rem 0; }
.section-tight { padding: 3.5rem 0; }
.section-header { max-width: 680px; margin-bottom: 3rem; }
.section-header.center { margin-left: auto; margin-right: auto; text-align: center; }

.bg-paper { background: var(--paper); }
.bg-white { background: var(--white); }
.bg-navy { background: var(--navy-900); color: var(--white); }
.bg-navy h2, .bg-navy h3, .bg-navy h4 { color: var(--white); }
.bg-navy p { color: rgba(255, 255, 255, 0.68); }
.bg-navy a.link-on-navy { color: var(--steel-300); text-decoration: underline; text-underline-offset: 2px; }
.bg-navy a.link-on-navy:hover { color: var(--white); }

.divider-line { border: none; border-top: 1px solid var(--line); margin: 0; }
.divider-line.on-dark { border-top-color: var(--line-on-dark); }

.grid { display: grid; gap: 1px; background: var(--line); border: 1px solid var(--line); }
.grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
.grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
.grid.cols-4 { grid-template-columns: repeat(4, 1fr); }

@media (max-width: 991.98px) {
  .grid.cols-3 { grid-template-columns: repeat(2, 1fr); }
  .grid.cols-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 575.98px) {
  .grid.cols-2, .grid.cols-3, .grid.cols-4 { grid-template-columns: 1fr; }
}

/* ------------------------------------------------------------------------
   Cards
   ------------------------------------------------------------------------ */

.card-cell {
  background: var(--white);
  padding: 2.4rem 2.2rem;
}
.grid.on-navy .card-cell { background: var(--navy-900); }
.grid.on-navy { background: var(--line-on-dark); border-color: var(--line-on-dark); }

.card-index {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--steel-500);
  margin-bottom: 1.1rem;
  display: block;
}

.card-cell h3 { font-size: 1.12rem; margin-bottom: 0.65rem; }
.card-cell p { font-size: 0.95rem; margin-bottom: 0; }
.card-cell .card-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--steel-600);
  margin-top: 1.1rem;
}

.icon-line {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  color: var(--steel-600);
  margin-bottom: 1.3rem;
}
.bg-navy .icon-line, .grid.on-navy .icon-line { border-color: var(--line-on-dark-strong); color: var(--steel-300); }

/* Capability list rows (used on solution pages) */
.cap-row {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 2.5rem;
  padding: 2.4rem 0;
  border-top: 1px solid var(--line);
}
.cap-row:last-child { padding-bottom: 0; }
.cap-row .cap-num { font-family: var(--font-mono); color: var(--steel-500); font-size: 0.85rem; }
.cap-row h3 { font-size: 1.15rem; margin-bottom: 0.5rem; }
.cap-row p { margin-bottom: 0; max-width: 640px; }

@media (max-width: 767.98px) {
  .cap-row { grid-template-columns: 1fr; gap: 0.6rem; }
}

/* Process steps */
.process-list { counter-reset: step; }
.process-item {
  position: relative;
  padding: 2.2rem 0 2.2rem 3.6rem;
  border-top: 1px solid var(--line-on-dark);
}
.process-item:first-child { border-top: none; }
.process-item::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0; top: 2.2rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--steel-400);
}
.process-item h4 { color: var(--white); margin-bottom: 0.4rem; font-size: 1.05rem; }
.process-item p { margin-bottom: 0; max-width: 560px; }

/* Stat band */
.stat-row { display: flex; flex-wrap: wrap; gap: 0; border-top: 1px solid var(--line-on-dark); border-bottom: 1px solid var(--line-on-dark); }
.stat-cell { flex: 1 1 200px; padding: 2.2rem 2rem; border-left: 1px solid var(--line-on-dark); }
.stat-cell:first-child { border-left: none; }
.stat-num { font-family: var(--font-mono); font-size: 1.9rem; color: var(--white); display: block; margin-bottom: 0.35rem; letter-spacing: -0.01em; }
.stat-label { font-size: 0.85rem; color: rgba(255,255,255,0.6); }

/* Values / principles list (About) */
.value-item { padding: 2.2rem 0; border-top: 1px solid var(--line); display: grid; grid-template-columns: 1fr 2.4fr; gap: 2rem; }
.value-item:first-child { border-top: none; }
.value-item h3 { font-size: 1.05rem; margin: 0; }
.value-item p { margin: 0; }
@media (max-width: 767.98px) {
  .value-item { grid-template-columns: 1fr; gap: 0.5rem; }
}

/* Framework / standards badges */
.badge-row { display: flex; flex-wrap: wrap; gap: 0.7rem; }
.badge-line {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.03em;
  color: var(--ink-muted);
  border: 1px solid var(--line);
  padding: 0.5rem 0.85rem;
}

/* CTA band */
.cta-band {
  background: var(--navy-900);
  color: var(--white);
  padding: 4rem 0;
  text-align: center;
}
.cta-band h2 { color: var(--white); margin-bottom: 0.6rem; }
.cta-band p { max-width: 520px; margin: 0 auto 2rem; }
.cta-band .hero-actions { justify-content: center; }

/* ------------------------------------------------------------------------
   Forms
   ------------------------------------------------------------------------ */

.form-field { margin-bottom: 1.5rem; }
.form-field label {
  display: block;
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--ink);
  margin-bottom: 0.5rem;
}
.form-field .form-control,
.form-field select.form-control {
  width: 100%;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--white);
  padding: 0.8rem 0.9rem;
  font-size: 0.95rem;
  font-family: var(--font-sans);
  color: var(--ink);
}
.form-field .form-control:focus {
  outline: none;
  border-color: var(--steel-500);
  box-shadow: 0 0 0 3px rgba(76, 113, 150, 0.14);
}
.form-field textarea.form-control { resize: vertical; min-height: 140px; }
.text-danger { color: #b3432b; font-size: 0.82rem; display: block; margin-top: 0.4rem; }
.field-validation-error { color: #b3432b; font-size: 0.82rem; display: block; margin-top: 0.4rem; }
.input-validation-error { border-color: #b3432b !important; }

.alert-success-line {
  border: 1px solid var(--steel-500);
  background: var(--paper);
  color: var(--ink);
  padding: 1.1rem 1.3rem;
  margin-bottom: 2rem;
  font-size: 0.95rem;
}

/* Contact layout */
.contact-layout { display: grid; grid-template-columns: 1.55fr 1fr; gap: 4.5rem; align-items: start; }
.contact-info h5 {
  font-size: 0.78rem; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--ink-faint); margin-bottom: 0.7rem;
}
.contact-info .info-block { padding-bottom: 2rem; margin-bottom: 2rem; border-bottom: 1px solid var(--line); }
.contact-info .info-block:last-child { border-bottom: none; margin-bottom: 0; padding-bottom: 0; }
.contact-info a.info-email { font-size: 1.05rem; font-weight: 600; color: var(--steel-600); }
@media (max-width: 899.98px) {
  .contact-layout { grid-template-columns: 1fr; gap: 2.5rem; }
}

/* ------------------------------------------------------------------------
   Footer
   ------------------------------------------------------------------------ */

.site-footer {
  background: var(--navy-950);
  color: rgba(255, 255, 255, 0.55);
  padding: 4rem 0 2rem;
  font-size: 0.9rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.6fr 1fr 1fr 1fr;
  gap: 2.5rem;
  padding-bottom: 3rem;
  border-bottom: 1px solid var(--line-on-dark);
  margin-bottom: 1.8rem;
}

.footer-grid h5 {
  color: rgba(255, 255, 255, 0.85);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 1.1rem;
}

.footer-grid ul { list-style: none; margin: 0; padding: 0; }
.footer-grid li { margin-bottom: 0.65rem; }
.footer-grid a { color: rgba(255, 255, 255, 0.6); font-size: 0.9rem; }
.footer-grid a:hover { color: var(--white); }

.footer-about p { color: rgba(255, 255, 255, 0.55); max-width: 320px; font-size: 0.9rem; }

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.4);
}
.footer-bottom a { color: rgba(255, 255, 255, 0.5); }
.footer-bottom a:hover { color: var(--white); }

@media (max-width: 767.98px) {
  .footer-grid { grid-template-columns: 1fr 1fr; }
}

/* ------------------------------------------------------------------------
   Utilities
   ------------------------------------------------------------------------ */

.mt-0 { margin-top: 0; }
.mb-0 { margin-bottom: 0; }
.text-center { text-align: center; }
.visually-hidden { position: absolute !important; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

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

[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 520ms ease, transform 520ms ease;
}
[data-reveal].is-visible { opacity: 1; transform: translateY(0); }
@media (prefers-reduced-motion: reduce) {
  [data-reveal] { opacity: 1; transform: none; }
}