:root {
    --bg: #0a0b0d;
    --panel: #111317;
    --fg: #e9ecef;
    --dim: #8a9099;
    --rule: #23262b;
    --err: #e5866f;
    --mono: "IBM Plex Mono", ui-monospace, Menlo, monospace;
    --sans: "IBM Plex Sans", system-ui, -apple-system, sans-serif;
  }
  * { box-sizing: border-box; }
  html, body { margin: 0; background: var(--bg); color: var(--fg); }
  body {
    font-family: var(--sans);
    min-height: 100svh;
    display: flex;
    flex-direction: column;
    padding: max(24px, env(safe-area-inset-top)) max(20px, env(safe-area-inset-right)) max(24px, env(safe-area-inset-bottom)) max(20px, env(safe-area-inset-left));
    position: relative;
  }
  body::before {
    content: "";
    position: fixed;
    inset: 0;
    background: url("topo.svg") center / cover no-repeat;
    opacity: .16;
    -webkit-mask-image: radial-gradient(ellipse 75% 70% at 72% 40%, #000 30%, transparent 85%);
            mask-image: radial-gradient(ellipse 75% 70% at 72% 40%, #000 30%, transparent 85%);
    pointer-events: none;
    z-index: 0;
  }
  .wrap { position: relative; z-index: 1; width: 100%; max-width: 1120px; margin: 0 auto; flex: 1; display: flex; flex-direction: column; }
  header { display: flex; justify-content: space-between; align-items: center; gap: 16px; padding-bottom: 20px; border-bottom: 1px solid var(--rule); }
  header img { height: 18px; width: auto; display: block; }
  a.logo { border: 0; }
  nav { display: flex; align-items: center; gap: 22px; }
  a.nav { font: 500 12px/1 var(--mono); letter-spacing: .14em; text-transform: uppercase; border: 0; color: var(--dim); }
  a.nav:hover, a.nav[aria-current] { color: var(--fg); }
  p.more { margin: 32px 0 0; font: 500 12px/1 var(--mono); letter-spacing: .14em; text-transform: uppercase; }
  p.more a { border-bottom: 1px solid var(--dim); padding-bottom: 4px; }
  .label { font-family: var(--mono); font-size: 11px; letter-spacing: .14em; text-transform: uppercase; color: var(--dim); }
  .btn {
    font: 500 12px/1 var(--mono);
    letter-spacing: .14em;
    text-transform: uppercase;
    color: var(--bg);
    background: var(--fg);
    border: 1px solid var(--fg);
    padding: 12px 18px;
    cursor: pointer;
  }
  .btn:hover { background: transparent; color: var(--fg); }
  .btn.ghost { background: transparent; color: var(--fg); border-color: var(--rule); }
  .btn.ghost:hover { border-color: var(--fg); }
  main { flex: 1; display: flex; flex-direction: column; justify-content: center; padding: 72px 0; }
  h1 {
    font-weight: 300;
    font-size: clamp(38px, 7.4vw, 92px);
    line-height: 1.02;
    letter-spacing: -0.025em;
    margin: 18px 0 28px;
    max-width: 13ch;
    text-wrap: balance;
  }
  h1.hero { max-width: none; white-space: nowrap; font-size: clamp(32px, 4.7vw, 70px); }
  @media (max-width: 900px) { h1.hero { font-size: clamp(32px, 8.6vw, 70px); } }
  p.tagline { font: 400 clamp(13px, 1.2vw, 15px)/1.4 var(--mono); letter-spacing: .16em; text-transform: uppercase; color: var(--fg); margin: -8px 0 26px; }
  p.lede { font-size: clamp(16px, 1.6vw, 19px); line-height: 1.6; color: var(--dim); max-width: 44ch; margin: 0; }
  dl { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); margin: 0; border-top: 1px solid var(--rule); }
  dl div { padding: 18px 20px 0 0; }
  dl div + div { padding-left: 20px; border-left: 1px solid var(--rule); }
  dt { margin-bottom: 8px; }
  dd { margin: 0; font-family: var(--mono); font-size: 14px; }
  a { color: var(--fg); text-decoration: none; border-bottom: 1px solid var(--dim); }
  a:hover { border-color: var(--fg); }
  footer { display: flex; justify-content: space-between; gap: 16px; padding-top: 40px; }

  /* contact panel */
  dialog {
    width: min(560px, 100vw);
    max-width: 100vw;
    height: 100svh;
    max-height: 100svh;
    margin: 0 0 0 auto;
    padding: 0;
    border: 0;
    border-left: 1px solid var(--rule);
    background: var(--panel);
    color: var(--fg);
  }
  dialog::backdrop { background: rgba(5, 6, 8, .72); }
  .panel { display: flex; flex-direction: column; min-height: 100%; padding: max(24px, env(safe-area-inset-top)) 28px max(28px, env(safe-area-inset-bottom)); }
  .panel-head { display: flex; justify-content: space-between; align-items: center; padding-bottom: 20px; border-bottom: 1px solid var(--rule); }
  .close { background: none; border: 0; color: var(--dim); font: 400 12px var(--mono); letter-spacing: .14em; text-transform: uppercase; cursor: pointer; padding: 8px 0 8px 12px; }
  .close:hover { color: var(--fg); }
  .panel h2 { font-weight: 300; font-size: 34px; letter-spacing: -0.02em; line-height: 1.1; margin: 28px 0 8px; }
  .panel p.note { color: var(--dim); line-height: 1.55; margin: 0 0 24px; font-size: 15px; }
  form { display: grid; gap: 18px; }
  .row2 { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
  label.f { display: grid; gap: 8px; }
  input, select, textarea {
    font: 400 16px/1.4 var(--sans);
    color: var(--fg);
    background: var(--bg);
    border: 1px solid var(--rule);
    border-radius: 0;
    padding: 12px 12px;
    width: 100%;
  }
  select { appearance: none; background-image: linear-gradient(45deg, transparent 50%, var(--dim) 50%), linear-gradient(135deg, var(--dim) 50%, transparent 50%); background-position: calc(100% - 18px) 50%, calc(100% - 13px) 50%; background-size: 5px 5px; background-repeat: no-repeat; padding-right: 36px; }
  textarea { min-height: 140px; resize: vertical; }
  input:focus, select:focus, textarea:focus { outline: none; border-color: var(--fg); }
  .opt { color: var(--dim); text-transform: none; letter-spacing: 0; }
  .hp { position: absolute; left: -9999px; width: 1px; height: 1px; overflow: hidden; }
  .status { font: 400 13px/1.5 var(--mono); color: var(--dim); min-height: 20px; }
  .status.err { color: var(--err); }
  .sent h2 { margin-top: 40px; }

  @media (max-width: 640px) {
    header img { height: 14px; }
    nav { gap: 14px; }
    .btn { padding: 10px 14px; }
    main { padding: 56px 0; }
    dl { grid-template-columns: 1fr; }
    dl div, dl div + div { padding: 16px 0; border-left: 0; border-bottom: 1px solid var(--rule); }
    footer { flex-direction: column; gap: 6px; }
    dialog { border-left: 0; }
    .panel { padding-left: 20px; padding-right: 20px; }
    .row2 { grid-template-columns: 1fr; }
  }

  /* OPHAN-V page */
  .intro { padding: 64px 0 40px; }
  .intro h1 { max-width: none; margin-bottom: 24px; }
  .intro .lede { max-width: 58ch; }
  figure.plate { margin: 0 0 8px; border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); }
  figure.plate img { display: block; width: 100%; max-width: 900px; height: auto; margin: 0 auto; }
  figure.plate figcaption { padding: 12px 0; border-top: 1px solid var(--rule); }
  section.specs, section.features { padding: 72px 0 24px; }
  .sec-head { display: grid; gap: 10px; padding-bottom: 20px; border-bottom: 1px solid var(--rule); }
  .sec-head h2 { font-weight: 300; font-size: clamp(28px, 3.4vw, 40px); letter-spacing: -0.02em; margin: 0; }
  table { width: 100%; border-collapse: collapse; }
  th, td { text-align: left; vertical-align: top; padding: 16px 0; border-bottom: 1px solid var(--rule); }
  th { width: 34%; font-weight: 400; padding-right: 20px; }
  td { font-family: var(--mono); font-size: 15px; }
  p.fine { color: var(--dim); font-size: 14px; line-height: 1.55; margin: 16px 0 0; }
  .features ol { list-style: none; margin: 0; padding: 0; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .features li { display: grid; grid-template-columns: 44px minmax(0, 1fr); gap: 8px; padding: 22px 24px 22px 0; border-bottom: 1px solid var(--rule); }
  .features li:nth-child(even) { padding-left: 24px; border-left: 1px solid var(--rule); }
  .features h3 { font-weight: 500; font-size: 17px; margin: 0 0 8px; }
  .features p { color: var(--dim); line-height: 1.55; margin: 0; font-size: 15px; }
  section.withheld { margin: 56px 0 0; padding: 24px 0; border-top: 1px solid var(--rule); border-bottom: 1px solid var(--rule); display: grid; gap: 10px; }
  section.withheld p { margin: 0; font-size: 17px; line-height: 1.5; max-width: 60ch; }
  @media (max-width: 640px) {
    .intro { padding: 44px 0 28px; }
    section.specs, section.features { padding: 52px 0 16px; }
    th { width: 44%; }
    td { font-size: 14px; }
    .features ol { grid-template-columns: 1fr; }
    .features li, .features li:nth-child(even) { padding: 18px 0; border-left: 0; }
  }

  /* products dropdown (home) */
  .products { position: relative; margin-top: 32px; align-self: flex-start; }
  .menu { position: absolute; top: calc(100% + 6px); left: 0; z-index: 5; list-style: none; margin: 0; padding: 0; min-width: 300px; background: var(--panel); border: 1px solid var(--rule); }
  .menu a { display: grid; gap: 6px; padding: 16px 18px; border: 0; }
  .menu a:hover { background: var(--bg); }
  .mname { font: 500 14px/1 var(--mono); letter-spacing: .1em; }
  .mdesc { color: var(--dim); font-size: 14px; }

  /* privacy page */
  .legal { padding: 64px 0 40px; max-width: 68ch; }
  .legal h1 { font-size: clamp(36px, 5vw, 60px); margin: 18px 0 32px; }
  .legal h2 { font-weight: 500; font-size: 17px; margin: 32px 0 10px; }
  .legal p { color: var(--dim); line-height: 1.65; margin: 0 0 12px; font-size: 16px; }
  footer a.nav { font-size: 11px; font-weight: 400; }

  /* home hero: text left, aircraft right */
  a.nav { white-space: nowrap; }
  main.hero-grid { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 0.9fr); align-items: center; gap: 32px; }
  .hero-text { min-width: 0; display: flex; flex-direction: column; }
  .hero-img { display: grid; gap: 10px; border: 0; }
  .hero-img img { width: 100%; height: auto; display: block; }
  .hero-img .label { text-align: right; }
  @media (max-width: 900px) {
    main.hero-grid { grid-template-columns: 1fr; gap: 24px; }
    .hero-img .label { text-align: left; }
  }