:root {
  --navy-950: #071421;
  --navy-900: #0b1d2c;
  --navy-800: #102a3e;
  --navy-700: #173b55;
  --steel-600: #587084;
  --steel-400: #91a3b2;
  --steel-200: #d7e0e7;
  --steel-100: #edf2f5;
  --white: #ffffff;
  --ink: #17202a;
  --muted: #5f6b76;
  --accent: #9f1d2d;
  --accent-dark: #7f1421;
  --max-width: 1180px;
  --radius: 12px;
  --shadow: 0 18px 50px rgba(6, 20, 33, 0.14);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Inter", Arial, sans-serif;
  color: var(--ink);
  background: var(--white);
  line-height: 1.65;
}
img, video { display: block; max-width: 100%; }
a { color: inherit; }
h1, h2, h3, p { margin-top: 0; }
h1, h2 {
  font-family: "Source Serif 4", Georgia, serif;
  line-height: 1.08;
  letter-spacing: -0.025em;
}
h1 { font-size: clamp(2.7rem, 6vw, 5.7rem); max-width: 980px; }
h2 { font-size: clamp(2.1rem, 4vw, 3.7rem); }
h3 { line-height: 1.25; }
.container { width: min(calc(100% - 40px), var(--max-width)); margin: 0 auto; }
.skip-link {
  position: absolute;
  left: -9999px;
  top: 12px;
  z-index: 9999;
  padding: 10px 14px;
  background: var(--white);
  color: var(--navy-950);
}
.skip-link:focus { left: 12px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(7, 20, 33, 0.96);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255,255,255,0.09);
}
.nav-wrap { min-height: 78px; display: flex; align-items: center; justify-content: space-between; gap: 32px; }
.brand { display: inline-flex; align-items: center; gap: 12px; color: var(--white); text-decoration: none; }
.brand-mark {
  width: 43px;
  height: 43px;
  border: 1px solid rgba(255,255,255,0.36);
  display: grid;
  place-items: center;
  font-weight: 700;
  letter-spacing: .05em;
}
.brand-text { display: flex; flex-direction: column; line-height: 1.2; }
.brand-text strong { font-size: .95rem; }
.brand-text small { font-size: .68rem; color: var(--steel-400); text-transform: uppercase; letter-spacing: .09em; }
.site-nav { display: flex; align-items: center; gap: 24px; }
.site-nav a { color: #d8e2e9; text-decoration: none; font-size: .9rem; font-weight: 500; }
.site-nav a:hover { color: var(--white); }
.nav-cta { border: 1px solid rgba(255,255,255,.32); padding: 9px 15px; }

.hero {
  position: relative;
  min-height: 760px;
  display: flex;
  align-items: center;
  color: var(--white);
  background:
    linear-gradient(115deg, rgba(7,20,33,.97) 15%, rgba(7,20,33,.86) 54%, rgba(7,20,33,.52) 100%),
    url("assets/images/hero-engineering.jpg") center/cover no-repeat;
  overflow: hidden;
}
.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.45), transparent);
}
.hero-content { position: relative; z-index: 2; padding: 110px 0 90px; }
.eyebrow {
  font-size: .76rem;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: #b9c9d4;
  margin-bottom: 18px;
}
.eyebrow.dark { color: var(--navy-700); }
.hero-lead { max-width: 760px; font-size: clamp(1.08rem, 2vw, 1.35rem); color: #d6e0e7; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 14px; margin: 34px 0 46px; }
.button { display: inline-block; padding: 13px 20px; text-decoration: none; font-weight: 600; border: 1px solid transparent; }
.button-primary { background: var(--accent); color: var(--white); }
.button-primary:hover { background: var(--accent-dark); }
.button-secondary { border-color: rgba(255,255,255,.42); color: var(--white); }
.button-secondary:hover { background: rgba(255,255,255,.08); }
.hero-signature { margin: 0; color: #aebfcb; font-size: .95rem; letter-spacing: .06em; text-transform: uppercase; }

.section { padding: 105px 0; }
.section-light { background: var(--white); }
.section-dark { background: var(--navy-950); color: var(--white); }
.section-heading { margin-bottom: 52px; }
.section-heading.narrow { max-width: 850px; }
.section-heading p:not(.eyebrow) { font-size: 1.08rem; color: var(--muted); }
.section-dark .section-heading p:not(.eyebrow), .lifecycle-section .section-heading p:not(.eyebrow) { color: #bdcbd4; }
.split-heading { display: grid; grid-template-columns: 1.3fr .8fr; gap: 70px; align-items: end; }

.method-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.method-card { border-top: 3px solid var(--navy-800); background: var(--steel-100); padding: 32px; min-height: 265px; }
.method-number { display: block; font-size: .78rem; font-weight: 700; letter-spacing: .12em; color: var(--accent); margin-bottom: 42px; }
.method-card h3 { font-size: 1.26rem; }
.method-card p { color: var(--muted); margin-bottom: 0; }

.video-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.video-card { background: var(--navy-900); border: 1px solid rgba(255,255,255,.1); box-shadow: 0 12px 28px rgba(0,0,0,.18); }
.video-frame { aspect-ratio: 16/9; background: #02070b; overflow: hidden; }
.video-frame video { width: 100%; height: 100%; object-fit: cover; }
.video-copy { padding: 26px; }
.card-kicker { margin-bottom: 10px; color: #9fb1bd; font-size: .72rem; font-weight: 700; letter-spacing: .14em; text-transform: uppercase; }
.video-copy h3 { margin-bottom: 12px; font-size: 1.3rem; }
.video-copy p:last-child { margin-bottom: 0; color: #b9c6cf; }

.discipline-grid { display: grid; grid-template-columns: repeat(2, 1fr); border-top: 1px solid var(--steel-200); border-left: 1px solid var(--steel-200); }
.discipline-item { padding: 28px 30px; border-right: 1px solid var(--steel-200); border-bottom: 1px solid var(--steel-200); }
.discipline-item h3 { margin-bottom: 6px; }
.discipline-item p { margin-bottom: 0; color: var(--muted); }

.lifecycle-section { background: var(--navy-800); color: var(--white); }
.lifecycle { display: grid; grid-template-columns: auto 1fr auto 1fr auto 1fr auto 1fr auto 1fr auto 1fr auto; align-items: center; gap: 12px; margin: 60px 0 56px; }
.lifecycle-step { display: flex; flex-direction: column; gap: 7px; min-width: 90px; }
.lifecycle-step span { color: #9eb0bc; font-size: .7rem; letter-spacing: .1em; }
.lifecycle-step strong { font-size: .85rem; line-height: 1.25; }
.lifecycle-line { height: 1px; background: rgba(255,255,255,.3); }
.experience-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.experience-grid article { border: 1px solid rgba(255,255,255,.13); padding: 26px; background: rgba(255,255,255,.035); }
.experience-grid p { color: #c0ccd4; margin-bottom: 0; }

.publication-list { border-top: 1px solid var(--steel-200); }
.publication { display: grid; grid-template-columns: 130px 1fr; gap: 30px; padding: 28px 0; border-bottom: 1px solid var(--steel-200); }
.publication-type { color: var(--accent); text-transform: uppercase; font-size: .72rem; font-weight: 700; letter-spacing: .12em; padding-top: 4px; }
.publication h3 { margin-bottom: 7px; }
.publication p { margin-bottom: 0; color: var(--muted); }

.brand-band { background: var(--accent); color: var(--white); padding: 54px 0; }
.brand-band-inner { display: flex; align-items: baseline; justify-content: space-between; gap: 40px; }
.brand-band p { margin: 0; text-transform: uppercase; letter-spacing: .15em; font-size: .75rem; font-weight: 700; }
.brand-band h2 { margin: 0; font-size: clamp(1.8rem, 3vw, 3rem); }

.contact-section { background: var(--navy-950); color: var(--white); }
.contact-grid { display: grid; grid-template-columns: 1.2fr .65fr; gap: 80px; align-items: start; }
.contact-grid > div:first-child p:not(.eyebrow) { color: #c0ccd4; max-width: 720px; }
.contact-card { border-left: 3px solid var(--accent); padding: 10px 0 10px 28px; }
.contact-card p { color: #c0ccd4; margin-bottom: 7px; }
.contact-card a { color: var(--white); }

.site-footer { background: #030a10; color: #8fa0ab; padding: 24px 0; font-size: .82rem; }
.footer-inner { display: flex; justify-content: space-between; gap: 30px; }
.footer-inner p { margin: 0; }

@media (max-width: 980px) {
  .site-nav { display: none; }
  .hero { min-height: 680px; }
  .split-heading, .contact-grid { grid-template-columns: 1fr; gap: 26px; }
  .method-grid, .video-grid { grid-template-columns: 1fr; }
  .video-card { display: grid; grid-template-columns: 1.1fr .9fr; }
  .experience-grid { grid-template-columns: repeat(2, 1fr); }
  .lifecycle { grid-template-columns: repeat(4, 1fr); gap: 20px; }
  .lifecycle-line { display: none; }
  .brand-band-inner { display: block; }
  .brand-band p { margin-bottom: 10px; }
}

@media (max-width: 680px) {
  .container { width: min(calc(100% - 28px), var(--max-width)); }
  .section { padding: 78px 0; }
  .hero { min-height: 630px; }
  .hero-content { padding: 85px 0 70px; }
  .video-card { display: block; }
  .discipline-grid { grid-template-columns: 1fr; }
  .experience-grid { grid-template-columns: 1fr; }
  .lifecycle { grid-template-columns: repeat(2, 1fr); }
  .publication { grid-template-columns: 1fr; gap: 8px; }
  .footer-inner { display: block; }
  .footer-inner p + p { margin-top: 7px; }
}