/* ============================================================
   Polaris Bridge Engineering LLC — site stylesheet
   Design language: structural plan sheet. Mono "sheet codes",
   double hairline rules, steel navy ink on drawing-paper white,
   weathering-steel accent reserved for primary actions.
   ============================================================ */

:root {
  --ink: #182432;        /* deep steel navy */
  --steel: #52606E;      /* secondary text */
  --paper: #F6F5F1;      /* plan-sheet ground */
  --panel: #FFFFFF;
  --rule: #D9D6CC;       /* hairlines */
  --rule-dark: #182432;
  --accent: #C24A18;     /* weathering steel / work-zone orange */
  --accent-dark: #A03C11;
  --mono: "IBM Plex Mono", ui-monospace, "SF Mono", Menlo, monospace;
  --sans: "Public Sans", -apple-system, "Segoe UI", Arial, sans-serif;
  --display: "Archivo", "Public Sans", Arial, sans-serif;
  --max: 1080px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}

body {
  font-family: var(--sans);
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--ink);
  background: var(--paper);
  -webkit-font-smoothing: antialiased;
}

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

a { color: var(--ink); }
a:hover { color: var(--accent-dark); }
a:focus-visible, button:focus-visible, input:focus-visible,
select:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

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

/* ---------- header / nav ---------- */
.site-header {
  background: var(--paper);
  border-bottom: 1px solid var(--rule);
  position: sticky; top: 0; z-index: 50;
}
.site-header .wrap {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; min-height: 72px;
}
.brand { display: flex; align-items: center; gap: .75rem; text-decoration: none; }
.brand img { height: 44px; width: auto; }
.brand-name {
  font-family: var(--display); font-weight: 700; font-size: 1.05rem;
  letter-spacing: .01em; line-height: 1.2;
}
.brand-name small {
  display: block; font-family: var(--mono); font-weight: 400;
  font-size: .62rem; letter-spacing: .14em; color: var(--steel);
  text-transform: uppercase; margin-top: .15rem;
}

.nav-toggle { display: none; }
.nav-toggle-label {
  display: none; cursor: pointer; font-size: 1.6rem; line-height: 1;
  padding: .25rem .5rem; border: 1px solid var(--rule);
}
nav.primary ul { display: flex; gap: 1.4rem; list-style: none; align-items: center; }
nav.primary a {
  text-decoration: none; font-size: .92rem; font-weight: 600;
  letter-spacing: .01em; padding: .35rem 0;
  border-bottom: 2px solid transparent;
}
nav.primary a:hover { border-bottom-color: var(--accent); color: var(--ink); }
nav.primary a[aria-current="page"] { border-bottom-color: var(--ink); }

@media (max-width: 900px) {
  .nav-toggle-label { display: block; }
  nav.primary {
    display: none; position: absolute; left: 0; right: 0; top: 100%;
    background: var(--paper); border-bottom: 1px solid var(--rule);
  }
  .nav-toggle:checked ~ nav.primary { display: block; }
  nav.primary ul { flex-direction: column; align-items: stretch; gap: 0; padding: .5rem 1.5rem 1rem; }
  nav.primary a { display: block; padding: .7rem 0; border-bottom: 1px solid var(--rule); }
}

/* ---------- hero ---------- */
.hero { position: relative; overflow: hidden; border-bottom: 1px solid var(--rule); }
.hero .wrap { position: relative; padding-top: 4.5rem; padding-bottom: 4rem; }
.hero-art {
  position: absolute; right: -40px; bottom: 0; width: 640px; max-width: 70%;
  opacity: .5; pointer-events: none;
}
.eyebrow {
  font-family: var(--mono); font-size: .72rem; letter-spacing: .22em;
  text-transform: uppercase; color: var(--accent-dark); margin-bottom: 1.1rem;
}
h1 {
  font-family: var(--display); font-weight: 700; letter-spacing: -.015em;
  font-size: clamp(2.1rem, 4.6vw, 3.3rem); line-height: 1.08;
  max-width: 15ch;
}
.hero p.lede { max-width: 56ch; margin: 1.4rem 0 1.8rem; font-size: 1.12rem; color: var(--steel); }
.proof-line {
  font-family: var(--mono); font-size: .78rem; letter-spacing: .04em;
  color: var(--ink); border-top: 2px solid var(--ink); border-bottom: 1px solid var(--ink);
  display: inline-block; padding: .55rem 0; margin-bottom: 1.9rem;
}
.cta-row { display: flex; flex-wrap: wrap; gap: .8rem; align-items: center; }
.btn {
  display: inline-block; text-decoration: none; font-weight: 600;
  font-size: .95rem; padding: .78rem 1.5rem; border: 1px solid var(--ink);
  transition: background .15s, color .15s;
}
.btn-primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-dark); border-color: var(--accent-dark); color: #fff; }
.btn-secondary { background: transparent; color: var(--ink); }
.btn-secondary:hover { background: var(--ink); color: #fff; }
.text-link { font-weight: 600; font-size: .95rem; }

/* ---------- section scaffolding ---------- */
section.block { padding: 4rem 0 4.2rem; }
section.block.alt { background: var(--panel); border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); }

.sheet-head { margin-bottom: 2.2rem; }
.sheet-code {
  font-family: var(--mono); font-size: .72rem; letter-spacing: .2em;
  text-transform: uppercase; color: var(--steel); display: block; margin-bottom: .55rem;
}
.sheet-head h2, .sheet-head h1 {
  font-family: var(--display); font-weight: 700; letter-spacing: -.01em;
  font-size: clamp(1.55rem, 3vw, 2.15rem); line-height: 1.15; max-width: 24ch;
}
.sheet-rule {
  border: 0; border-top: 3px solid var(--ink); position: relative;
  margin-top: .9rem;
}
.sheet-rule::after {
  content: ""; display: block; border-top: 1px solid var(--ink); margin-top: 3px;
}
.sheet-head p.sub { color: var(--steel); max-width: 66ch; margin-top: 1.1rem; }

/* ---------- cards & grids ---------- */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 1.4rem; }
.grid-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.2rem; }
@media (max-width: 900px) { .grid-4 { grid-template-columns: 1fr 1fr; } }
@media (max-width: 620px) { .grid-2, .grid-4 { grid-template-columns: 1fr; } }

.card {
  background: var(--panel); border: 1px solid var(--rule); padding: 1.5rem 1.4rem;
  display: flex; flex-direction: column; gap: .6rem;
}
section.block.alt .card { background: var(--paper); }
.card h3 {
  font-family: var(--display); font-size: 1.08rem; font-weight: 700; line-height: 1.3;
}
.card p { font-size: .95rem; color: var(--steel); }
.card .text-link { margin-top: auto; }

.kicker {
  font-family: var(--mono); font-size: .68rem; letter-spacing: .16em;
  text-transform: uppercase; color: var(--accent-dark);
}

/* definition-style feature list */
.feature-list { display: grid; gap: 1.1rem; max-width: 70ch; }
.feature-list p strong { font-family: var(--display); }

/* ---------- experience / case studies ---------- */
.case {
  background: var(--panel); border: 1px solid var(--rule);
  border-left: 4px solid var(--ink); padding: 1.6rem 1.6rem 1.4rem; margin-bottom: 1.3rem;
}
.case h3 { font-family: var(--display); font-size: 1.12rem; font-weight: 700; }
.case .meta {
  font-family: var(--mono); font-size: .7rem; letter-spacing: .12em;
  text-transform: uppercase; color: var(--steel); margin: .25rem 0 .8rem;
}
.case dl { display: grid; grid-template-columns: 150px 1fr; row-gap: .5rem; column-gap: 1rem; }
.case dt { font-weight: 700; font-size: .88rem; }
.case dd { font-size: .95rem; color: var(--steel); }
@media (max-width: 620px) { .case dl { grid-template-columns: 1fr; } .case dd { margin-bottom: .4rem; } }

.attribution {
  background: var(--panel); border: 1px solid var(--ink); padding: 1.2rem 1.4rem;
  font-size: .9rem; color: var(--steel); margin: 1.6rem 0;
}
.attribution strong { color: var(--ink); font-family: var(--mono); font-size: .72rem; letter-spacing: .16em; text-transform: uppercase; display: block; margin-bottom: .4rem; }

/* ---------- content typography ---------- */
.prose { max-width: 70ch; }
.prose h2 { font-family: var(--display); font-size: 1.45rem; margin: 2.4rem 0 .8rem; }
.prose h3 { font-family: var(--display); font-size: 1.12rem; margin: 1.8rem 0 .5rem; }
.prose p { margin: 0 0 1rem; }
.prose ul { margin: 0 0 1.2rem 1.2rem; }
.prose li { margin-bottom: .4rem; }
.prose .standards { font-size: .9rem; color: var(--steel); font-style: italic; }

/* ---------- proof bar / stats strip ---------- */
.proof-bar {
  display: grid; grid-template-columns: repeat(4, 1fr);
  border-top: 3px solid var(--ink); border-bottom: 1px solid var(--ink);
}
.proof-bar div { padding: 1.1rem .9rem; border-left: 1px solid var(--rule); }
.proof-bar div:first-child { border-left: 0; }
.proof-bar .k { font-family: var(--display); font-weight: 700; font-size: 1.15rem; display: block; }
.proof-bar .v { font-family: var(--mono); font-size: .68rem; letter-spacing: .12em; text-transform: uppercase; color: var(--steel); }
@media (max-width: 780px) { .proof-bar { grid-template-columns: 1fr 1fr; } .proof-bar div:nth-child(3) { border-left: 0; } }

/* ---------- CTA band ---------- */
.cta-band { background: var(--ink); color: #fff; padding: 3.4rem 0; }
.cta-band h2 { font-family: var(--display); font-size: clamp(1.5rem, 3vw, 2rem); max-width: 22ch; }
.cta-band p { color: #B9C2CC; max-width: 62ch; margin: .9rem 0 1.6rem; }
.cta-band .btn-secondary { color: #fff; border-color: #fff; }
.cta-band .btn-secondary:hover { background: #fff; color: var(--ink); }

/* ---------- forms ---------- */
form.inquiry { display: grid; gap: 1.1rem; max-width: 640px; }
.field label { display: block; font-weight: 600; font-size: .9rem; margin-bottom: .3rem; }
.field .req { color: var(--accent-dark); }
.field input, .field select, .field textarea {
  width: 100%; font: inherit; font-size: .98rem; padding: .65rem .75rem;
  border: 1px solid var(--steel); background: var(--panel); color: var(--ink);
}
.field textarea { min-height: 140px; resize: vertical; }
.form-note { font-size: .85rem; color: var(--steel); }
.form-status { display: none; padding: .9rem 1.1rem; font-size: .95rem; border: 1px solid; }
.form-status.ok { display: block; border-color: #2E6B3F; background: #EAF3EC; color: #23532F; }
.form-status.err { display: block; border-color: var(--accent-dark); background: #F8ECE5; color: var(--accent-dark); }

/* ---------- footer (title block) ---------- */
.site-footer { background: var(--panel); border-top: 3px solid var(--ink); margin-top: 0; }
.footer-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr 1.2fr; gap: 2rem;
  padding: 2.8rem 0 2.2rem;
}
@media (max-width: 900px) { .footer-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 620px) { .footer-grid { grid-template-columns: 1fr; } }
.site-footer h4 {
  font-family: var(--mono); font-size: .7rem; letter-spacing: .18em;
  text-transform: uppercase; color: var(--steel); margin-bottom: .8rem;
}
.site-footer p, .site-footer li, .site-footer a { font-size: .92rem; color: var(--steel); }
.site-footer ul { list-style: none; }
.site-footer li { margin-bottom: .45rem; }
.site-footer a { text-decoration: none; }
.site-footer a:hover { color: var(--accent-dark); text-decoration: underline; }
.footer-legal {
  border-top: 1px solid var(--rule); padding: 1.1rem 0 1.4rem;
  font-family: var(--mono); font-size: .72rem; letter-spacing: .05em; color: var(--steel);
  display: flex; flex-wrap: wrap; gap: .4rem 2rem; justify-content: space-between;
}