/* Zehterra — premium aerospace visual system
   Palette: black / near-black / white / silver / cool grey only */

:root {
  --bg: #050607;
  --bg-elev: #0a0b0d;
  --bg-panel: #0e1012;
  --bg-soft: #14161a;
  --line: rgba(197, 206, 216, 0.14);
  --line-strong: rgba(197, 206, 216, 0.28);
  --text: #e8eef4;
  --text-dim: #9aa3ae;
  --text-mute: #6a7380;
  --silver: #c5ced8;
  --steel: #8a939e;
  --white: #f4f7fa;
  --glow: rgba(200, 210, 220, 0.06);
  --radius: 18px;
  --radius-sm: 10px;
  --max: 1180px;
  --header-h: 72px;
  --font: "Outfit", "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  font-size: 1.05rem;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--silver); text-decoration: none; transition: color 0.25s var(--ease); }
a:hover { color: var(--white); }
:focus-visible { outline: 1px solid var(--silver); outline-offset: 3px; }

.skip-link {
  position: absolute; left: -999px; top: 0; background: var(--bg-panel);
  color: var(--white); padding: 0.75rem 1rem; z-index: 1000;
}
.skip-link:focus { left: 1rem; top: 1rem; }

/* ——— Header ——— */
.site-header {
  position: fixed; inset: 0 0 auto 0; height: var(--header-h);
  z-index: 100;
  background: rgba(5, 6, 7, 0.72);
  backdrop-filter: blur(16px) saturate(1.2);
  -webkit-backdrop-filter: blur(16px) saturate(1.2);
  border-bottom: 1px solid transparent;
  transition: border-color 0.35s var(--ease), background 0.35s var(--ease);
}
.site-header.is-scrolled { border-bottom-color: var(--line); background: rgba(5, 6, 7, 0.88); }

.header-inner {
  max-width: calc(var(--max) + 4rem);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 100%;
  display: flex; align-items: center; justify-content: space-between; gap: 1.5rem;
}

.logo {
  display: inline-flex; align-items: center; gap: 0.7rem;
  color: var(--white); font-weight: 600; letter-spacing: 0.08em;
  text-transform: uppercase; font-size: 0.92rem;
}
.logo-mark { width: 28px; height: 28px; flex-shrink: 0; }
.logo-mark svg { width: 100%; height: 100%; display: block; }

.nav-toggle {
  display: none;
  background: transparent; border: 1px solid var(--line-strong);
  color: var(--text); border-radius: 999px;
  padding: 0.45rem 0.9rem; font: inherit; font-size: 0.85rem;
  letter-spacing: 0.06em; text-transform: uppercase; cursor: pointer;
}

.site-nav ul {
  list-style: none; margin: 0; padding: 0;
  display: flex; align-items: center; gap: 0.15rem 1.35rem;
}
.site-nav a {
  color: var(--text-dim); font-size: 0.82rem; letter-spacing: 0.08em;
  text-transform: uppercase; padding: 0.35rem 0;
  position: relative;
}
.site-nav a::after {
  content: ""; position: absolute; left: 0; right: 100%; bottom: 0;
  height: 1px; background: var(--silver);
  transition: right 0.35s var(--ease);
}
.site-nav a:hover, .site-nav a[aria-current="page"] { color: var(--white); }
.site-nav a:hover::after, .site-nav a[aria-current="page"]::after { right: 0; }

@media (max-width: 860px) {
  .nav-toggle { display: inline-flex; }
  .site-nav {
    position: fixed; inset: var(--header-h) 0 auto 0;
    background: rgba(8, 9, 11, 0.96);
    border-bottom: 1px solid var(--line);
    padding: 1rem 1.5rem 1.25rem;
    transform: translateY(-120%);
    opacity: 0; pointer-events: none;
    transition: transform 0.4s var(--ease), opacity 0.35s var(--ease);
  }
  .site-nav.is-open { transform: translateY(0); opacity: 1; pointer-events: auto; }
  .site-nav ul { flex-direction: column; align-items: flex-start; gap: 0.85rem; }
}

/* ——— Layout ——— */
.wrap { max-width: var(--max); margin: 0 auto; padding: 0 1.5rem; }
.section {
  padding: 7rem 0;
  position: relative;
}
.section-tight { padding: 5rem 0; }
.section-label {
  display: inline-block;
  font-size: 0.72rem; letter-spacing: 0.22em; text-transform: uppercase;
  color: var(--steel); margin-bottom: 1.1rem;
}
.section-title {
  font-size: clamp(1.75rem, 4vw, 2.85rem);
  font-weight: 500; letter-spacing: -0.02em; line-height: 1.12;
  color: var(--white); margin: 0 0 1.25rem; max-width: 18ch;
}
.section-title.wide { max-width: 22ch; }
.section-lede {
  color: var(--text-dim); max-width: 54ch; margin: 0 0 2.5rem;
  font-size: 1.05rem; line-height: 1.65;
}
.divider {
  border: 0; height: 1px; background: var(--line); margin: 0;
}

/* ——— Buttons ——— */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 0.55rem;
  padding: 0.95rem 1.55rem; border-radius: 999px;
  font: inherit; font-size: 0.78rem; font-weight: 500;
  letter-spacing: 0.14em; text-transform: uppercase;
  border: 1px solid transparent; cursor: pointer;
  transition: background 0.3s var(--ease), border-color 0.3s var(--ease),
              color 0.3s var(--ease), transform 0.3s var(--ease);
}
.btn-primary {
  background: var(--white); color: var(--bg); border-color: var(--white);
}
.btn-primary:hover { background: var(--silver); color: var(--bg); }
.btn-ghost {
  background: transparent; color: var(--white); border-color: var(--line-strong);
}
.btn-ghost:hover { border-color: var(--silver); background: var(--glow); }
.btn-row { display: flex; flex-wrap: wrap; gap: 0.85rem; }

/* ——— Hero ——— */
.hero {
  min-height: 100vh; min-height: 100dvh;
  display: grid; align-items: end;
  position: relative; overflow: hidden;
  padding: calc(var(--header-h) + 2rem) 0 4rem;
}
.hero-media {
  position: absolute; inset: 0; z-index: 0;
}
.hero-media img {
  width: 100%; height: 100%; object-fit: cover; object-position: center 40%;
  transform: scale(1.02);
}
.hero-media::after {
  content: ""; position: absolute; inset: 0;
  background:
    linear-gradient(180deg, rgba(5,6,7,0.35) 0%, rgba(5,6,7,0.15) 35%, rgba(5,6,7,0.75) 70%, rgba(5,6,7,0.97) 100%),
    linear-gradient(90deg, rgba(5,6,7,0.85) 0%, rgba(5,6,7,0.25) 45%, rgba(5,6,7,0.4) 100%);
}
.hero-content {
  position: relative; z-index: 1;
  max-width: var(--max); margin: 0 auto; padding: 0 1.5rem;
}
.hero-kicker {
  font-size: 0.72rem; letter-spacing: 0.28em; text-transform: uppercase;
  color: var(--steel); margin: 0 0 1.25rem;
}
.hero h1 {
  font-size: clamp(2rem, 5.2vw, 3.65rem);
  font-weight: 500; letter-spacing: -0.025em; line-height: 1.05;
  color: var(--white); margin: 0 0 1.35rem; max-width: 16ch;
}
.hero-support {
  color: var(--text-dim); max-width: 48ch; margin: 0 0 2.25rem;
  font-size: 1.08rem; line-height: 1.65;
}
.hero-scroll {
  position: absolute; bottom: 1.5rem; left: 50%; transform: translateX(-50%);
  z-index: 2; color: var(--text-mute); font-size: 0.68rem;
  letter-spacing: 0.2em; text-transform: uppercase;
  display: flex; flex-direction: column; align-items: center; gap: 0.5rem;
}
.hero-scroll span {
  width: 1px; height: 36px; background: linear-gradient(var(--silver), transparent);
  display: block;
}

/* ——— Vision ——— */
.vision-grid {
  display: grid; gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  margin-top: 2.5rem;
}
.vision-card {
  padding: 1.6rem 1.5rem;
  background: linear-gradient(160deg, rgba(20,22,26,0.9), rgba(10,11,13,0.95));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  transition: border-color 0.35s var(--ease), transform 0.4s var(--ease);
}
.vision-card:hover { border-color: var(--line-strong); transform: translateY(-2px); }
.vision-card h3 {
  margin: 0 0 0.55rem; font-size: 0.95rem; font-weight: 500;
  letter-spacing: 0.04em; color: var(--white);
}
.vision-card p { margin: 0; color: var(--text-dim); font-size: 0.95rem; }

/* ——— Platform ——— */
.platform-layout {
  display: grid; gap: 3rem; align-items: center;
  grid-template-columns: 1.05fr 0.95fr;
}
@media (max-width: 900px) { .platform-layout { grid-template-columns: 1fr; } }
.platform-visual {
  position: relative; border-radius: var(--radius); overflow: hidden;
  border: 1px solid var(--line); background: var(--bg-panel);
}
.platform-visual img { width: 100%; }
.feature-list { list-style: none; margin: 0; padding: 0; display: grid; gap: 1.15rem; }
.feature-list li {
  padding-left: 1.25rem; border-left: 1px solid var(--line-strong);
}
.feature-list strong {
  display: block; color: var(--white); font-weight: 500;
  font-size: 0.92rem; letter-spacing: 0.04em; margin-bottom: 0.25rem;
}
.feature-list span { color: var(--text-dim); font-size: 0.95rem; }

/* ——— Engineering ——— */
.eng-grid {
  display: grid; gap: 1.25rem;
  grid-template-columns: repeat(3, 1fr);
  margin-top: 2.5rem;
}
@media (max-width: 900px) { .eng-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .eng-grid { grid-template-columns: 1fr; } }
.eng-item {
  padding: 1.75rem 1.5rem;
  background: var(--bg-panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  position: relative; overflow: hidden;
}
.eng-item::before {
  content: ""; position: absolute; top: 0; left: 0; right: 0; height: 1px;
  background: linear-gradient(90deg, transparent, var(--silver), transparent);
  opacity: 0.35;
}
.eng-item h3 {
  margin: 0 0 0.6rem; font-size: 1rem; font-weight: 500; color: var(--white);
}
.eng-item p { margin: 0; color: var(--text-dim); font-size: 0.95rem; }

/* ——— Applications ——— */
.app-grid {
  display: grid; gap: 1rem;
  grid-template-columns: repeat(3, 1fr);
  margin-top: 2.5rem;
}
@media (max-width: 900px) { .app-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .app-grid { grid-template-columns: 1fr; } }
.app-card {
  padding: 1.85rem 1.5rem 1.7rem;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background:
    linear-gradient(145deg, rgba(255,255,255,0.03), transparent 40%),
    var(--bg-elev);
  min-height: 160px;
  transition: border-color 0.35s var(--ease), background 0.35s var(--ease);
}
.app-card:hover { border-color: var(--line-strong); }
.app-card .num {
  font-size: 0.7rem; letter-spacing: 0.18em; color: var(--text-mute);
  margin-bottom: 1rem;
}
.app-card h3 {
  margin: 0 0 0.55rem; font-size: 1.05rem; font-weight: 500; color: var(--white);
}
.app-card p { margin: 0; color: var(--text-dim); font-size: 0.92rem; }

/* ——— Ecosystem ——— */
.eco-wrap {
  margin-top: 2.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  overflow: hidden; background: var(--bg-panel);
}
.eco-wrap img { width: 100%; }
.eco-flow {
  display: flex; flex-wrap: wrap; gap: 0.5rem; align-items: center;
  justify-content: center; padding: 1.5rem 1rem 1.75rem;
  border-top: 1px solid var(--line);
}
.eco-node {
  padding: 0.55rem 1rem; border-radius: 999px;
  border: 1px solid var(--line-strong); color: var(--silver);
  font-size: 0.72rem; letter-spacing: 0.12em; text-transform: uppercase;
  background: rgba(255,255,255,0.02);
}
.eco-arrow { color: var(--text-mute); font-size: 0.85rem; }

/* ——— Roadmap ——— */
.roadmap {
  margin-top: 2.75rem;
  display: grid; gap: 0;
  position: relative;
}
.roadmap::before {
  content: ""; position: absolute; left: 11px; top: 8px; bottom: 8px; width: 1px;
  background: linear-gradient(var(--silver), var(--line));
  opacity: 0.45;
}
@media (min-width: 800px) {
  .roadmap {
    grid-template-columns: repeat(6, 1fr); gap: 0.75rem;
  }
  .roadmap::before {
    left: 4%; right: 4%; top: 18px; bottom: auto; height: 1px; width: auto;
  }
}
.road-step {
  position: relative; padding: 0 0 1.75rem 2.5rem;
}
@media (min-width: 800px) {
  .road-step { padding: 2.5rem 0.5rem 0; text-align: center; }
}
.road-step .dot {
  position: absolute; left: 5px; top: 4px;
  width: 13px; height: 13px; border-radius: 50%;
  background: var(--bg); border: 1.5px solid var(--silver);
}
@media (min-width: 800px) {
  .road-step .dot { left: 50%; transform: translateX(-50%); top: 12px; }
}
.road-step.is-focus .dot {
  background: var(--silver); box-shadow: 0 0 0 4px rgba(197,206,216,0.15);
}
.road-step h3 {
  margin: 0 0 0.4rem; font-size: 0.88rem; font-weight: 500;
  letter-spacing: 0.06em; text-transform: uppercase; color: var(--white);
}
.road-step p { margin: 0; color: var(--text-dim); font-size: 0.88rem; }
.road-step.is-focus h3 { color: var(--white); }
.road-note {
  margin-top: 2rem; padding: 1.25rem 1.5rem;
  border-left: 1px solid var(--silver);
  color: var(--text-dim); font-size: 0.98rem; max-width: 60ch;
}

/* ——— Family ——— */
.family-visual {
  margin-top: 2.5rem; border-radius: var(--radius);
  border: 1px solid var(--line); overflow: hidden; background: var(--bg-panel);
}
.family-visual img { width: 100%; }

/* ——— About ——— */
.about-panel {
  display: grid; gap: 2.5rem;
  grid-template-columns: 1.1fr 0.9fr;
  align-items: start;
}
@media (max-width: 800px) { .about-panel { grid-template-columns: 1fr; } }
.about-panel .prose p { color: var(--text-dim); margin: 0 0 1rem; max-width: 52ch; }
.about-meta {
  padding: 1.75rem; border-radius: var(--radius);
  border: 1px solid var(--line); background: var(--bg-panel);
}
.about-meta dl { margin: 0; display: grid; gap: 1.1rem; }
.about-meta dt {
  font-size: 0.7rem; letter-spacing: 0.16em; text-transform: uppercase;
  color: var(--text-mute); margin-bottom: 0.25rem;
}
.about-meta dd { margin: 0; color: var(--white); font-size: 0.98rem; }

/* ——— Contact ——— */
.contact-hero-title {
  font-size: clamp(1.85rem, 4vw, 2.75rem);
  font-weight: 500; letter-spacing: -0.02em; color: var(--white);
  margin: 0 0 1rem; max-width: 16ch;
}
.contact-grid {
  display: grid; gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  margin-top: 2.5rem;
}
.contact-card {
  display: block; padding: 1.6rem 1.4rem;
  border-radius: var(--radius); border: 1px solid var(--line);
  background: var(--bg-panel);
  transition: border-color 0.35s var(--ease), transform 0.35s var(--ease);
}
.contact-card:hover { border-color: var(--silver); transform: translateY(-2px); color: inherit; }
.contact-card h3 {
  margin: 0 0 0.4rem; font-size: 0.95rem; font-weight: 500; color: var(--white);
}
.contact-card p { margin: 0 0 0.85rem; color: var(--text-dim); font-size: 0.9rem; }
.contact-card .mail {
  font-size: 0.82rem; letter-spacing: 0.04em; color: var(--silver);
}

/* ——— Footer ——— */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 2.5rem 0 2.75rem;
  margin-top: 2rem;
}
.footer-inner {
  max-width: var(--max); margin: 0 auto; padding: 0 1.5rem;
  display: flex; flex-wrap: wrap; gap: 1.5rem 2rem;
  align-items: center; justify-content: space-between;
}
.footer-brand strong {
  display: block; color: var(--white); font-weight: 500;
  letter-spacing: 0.1em; text-transform: uppercase; font-size: 0.85rem;
  margin-bottom: 0.35rem;
}
.footer-brand span { color: var(--text-mute); font-size: 0.88rem; }
.footer-nav { display: flex; flex-wrap: wrap; gap: 1rem 1.35rem; }
.footer-nav a {
  font-size: 0.75rem; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--text-dim);
}
.footer-meta {
  width: 100%; margin: 0.5rem 0 0;
  color: var(--text-mute); font-size: 0.8rem;
}

/* ——— Reveal animations ——— */
.reveal {
  opacity: 0; transform: translateY(18px);
  transition: opacity 0.8s var(--ease), transform 0.8s var(--ease);
}
.reveal.is-in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; }
}

/* ——— Secondary pages ——— */
.page-hero {
  padding: calc(var(--header-h) + 4rem) 0 3rem;
}
.page-hero h1 {
  font-size: clamp(2rem, 4vw, 2.8rem); font-weight: 500;
  letter-spacing: -0.02em; margin: 0 0 1rem; color: var(--white);
}
.page-hero p { color: var(--text-dim); max-width: 48ch; margin: 0; }

.media-caption {
  font-size: 0.72rem; letter-spacing: 0.12em; text-transform: uppercase;
  color: var(--text-mute); padding: 0.85rem 1.1rem;
  border-top: 1px solid var(--line);
}


/* ——— Bleed media (hangar) ——— */
.bleed-media {
  margin: 0;
  width: 100%;
  position: relative;
  overflow: hidden;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  background: var(--bg-panel);
}
.bleed-media img {
  width: 100%;
  height: clamp(220px, 42vw, 520px);
  object-fit: cover;
  object-position: center;
}
.bleed-media .media-caption {
  max-width: var(--max);
  margin: 0 auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
  border-top: 0;
}

/* ——— Mission image cards ——— */
.app-card.mission-card {
  position: relative;
  overflow: hidden;
  min-height: 240px;
  padding: 0;
  display: flex;
  align-items: flex-end;
  background:
    linear-gradient(180deg, rgba(5,6,7,0.15) 0%, rgba(5,6,7,0.88) 72%, rgba(5,6,7,0.97) 100%),
    var(--mission-img) center / cover no-repeat,
    var(--bg-elev);
}
.app-card.mission-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(5,6,7,0.2) 0%, rgba(5,6,7,0.55) 45%, rgba(5,6,7,0.94) 100%);
  pointer-events: none;
}
.mission-card-body {
  position: relative;
  z-index: 1;
  padding: 1.85rem 1.5rem 1.7rem;
  width: 100%;
}
.app-card.mission-card .num { color: rgba(197, 206, 216, 0.7); }
.app-card.mission-card h3 { color: var(--white); }
.app-card.mission-card p { color: rgba(232, 238, 244, 0.82); }
.app-card.mission-card:hover {
  border-color: var(--silver);
}

/* ——— Energy ——— */
.energy-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(3, 1fr);
  margin-top: 0.5rem;
}
@media (max-width: 900px) { .energy-grid { grid-template-columns: 1fr; } }
.energy-card {
  padding: 1.75rem 1.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--line);
  background:
    linear-gradient(160deg, rgba(20,22,26,0.95), rgba(10,11,13,0.98));
  transition: border-color 0.35s var(--ease);
}
.energy-card:hover { border-color: var(--line-strong); }
.energy-card h3 {
  margin: 0 0 0.55rem;
  font-size: 1rem;
  font-weight: 500;
  color: var(--white);
}
.energy-card p {
  margin: 0;
  color: var(--text-dim);
  font-size: 0.95rem;
}
.energy-visual {
  margin-top: 2.5rem;
}

/* ——— Ecosystem clean (no diagram image) ——— */
.eco-wrap--clean {
  background:
    radial-gradient(ellipse at 50% 0%, rgba(197,206,216,0.06), transparent 55%),
    var(--bg-panel);
}
.eco-wrap--clean .eco-flow {
  border-top: 0;
  padding: 2.25rem 1.25rem;
}

/* ——— Family prose note ——— */
.family-note {
  margin: 0;
  max-width: 58ch;
  padding: 1.35rem 1.5rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-panel);
  color: var(--text-dim);
  font-size: 0.98rem;
  line-height: 1.65;
}