/* Biplane site — shared styles. Dark-first, follows the browser theme, responsive. */
:root {
  --bg: #0a0e14;
  --bg2: #0f141c;
  --panel: #131a24;
  --border: #223041;
  --text: #e8eef5;
  --muted: #93a4b7;
  --accent: #4c9aff;
  --accent2: #7ee0c2;
  --glow: rgba(76, 154, 255, 0.35);
}
@media (prefers-color-scheme: light) {
  :root {
    --bg: #f7f9fc;
    --bg2: #eef2f7;
    --panel: #ffffff;
    --border: #d7dfe9;
    --text: #16202c;
    --muted: #5c6b7c;
    --accent: #0b6cdd;
    --accent2: #0c8f6f;
    --glow: rgba(11, 108, 221, 0.18);
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.65 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* nav */
nav {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; gap: 20px;
  padding: 12px clamp(16px, 4vw, 40px);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
nav .brand { display: flex; align-items: center; gap: 10px; font-weight: 750; font-size: 17px; color: var(--text); }
nav .links { margin-left: auto; display: flex; gap: 4px clamp(8px, 2vw, 22px); flex-wrap: wrap; }
nav .links a { color: var(--muted); font-size: 14px; font-weight: 550; padding: 6px 8px; border-radius: 6px; }
nav .links a:hover { color: var(--text); text-decoration: none; background: var(--panel); }
nav .gh {
  border: 1px solid var(--border); border-radius: 8px; padding: 6px 14px;
  color: var(--text) !important; background: var(--panel);
}

main { max-width: 1080px; margin: 0 auto; padding: 0 clamp(16px, 4vw, 40px) 60px; }

/* hero */
.hero { position: relative; text-align: center; padding: clamp(48px, 9vw, 96px) 0 40px; overflow: hidden; }
.hero::before {
  content: ""; position: absolute; inset: -40% -20% auto; height: 130%;
  background: radial-gradient(ellipse 60% 50% at 50% 0%, var(--glow), transparent 70%);
  pointer-events: none;
}
.hero .plane { display: inline-block; animation: climb 2.4s ease-in-out infinite alternate; filter: drop-shadow(0 6px 24px var(--glow)); }
@keyframes climb {
  0% { transform: translate(-10px, 8px) rotate(1deg); }
  100% { transform: translate(10px, -8px) rotate(-2deg); }
}
.hero h1 {
  font-size: clamp(42px, 8vw, 72px); margin: 10px 0 6px; letter-spacing: -1.5px; line-height: 1.05;
}
.hero .tagline {
  font-size: clamp(19px, 3vw, 26px); font-weight: 700; margin: 0 0 14px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero .sub { color: var(--muted); max-width: 620px; margin: 0 auto 30px; font-size: clamp(15px, 2vw, 18px); }
.cta { display: flex; gap: 12px; justify-content: center; flex-wrap: wrap; }
.cta a {
  padding: 12px 26px; border-radius: 10px; font-weight: 650; font-size: 15px; text-decoration: none;
}
.cta a:hover { text-decoration: none; filter: brightness(1.1); }
.cta .primary { background: linear-gradient(90deg, var(--accent), color-mix(in srgb, var(--accent) 60%, var(--accent2))); color: #fff; box-shadow: 0 6px 24px var(--glow); }
.cta .ghost { border: 1px solid var(--border); color: var(--text); background: var(--panel); }

/* sections */
section { margin-top: clamp(48px, 7vw, 84px); }
h2 { font-size: clamp(24px, 4vw, 34px); letter-spacing: -0.5px; margin: 0 0 8px; }
.lede { color: var(--muted); max-width: 700px; margin: 0 0 26px; }

/* the two wings */
.wings { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 16px; }
.wing { background: linear-gradient(180deg, var(--panel), var(--bg2)); border: 1px solid var(--border); border-radius: 14px; padding: 22px 24px; }
.wing h3 { margin: 0 0 8px; font-size: 18px; }
.wing p { margin: 0; color: var(--muted); font-size: 15px; }
.wing .chip { display: inline-block; font-size: 12px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; color: var(--accent); margin-bottom: 10px; }
.wing:last-child .chip { color: var(--accent2); }

/* features */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; }
.card {
  background: var(--panel); border: 1px solid var(--border); border-radius: 14px; padding: 20px 22px;
  transition: transform .18s ease, border-color .18s ease;
}
.card:hover { transform: translateY(-3px); border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
.card b { display: block; margin-bottom: 6px; font-size: 15.5px; }
.card span { color: var(--muted); font-size: 14px; }

/* prose pages (terms/privacy/contact) + explainer */
.prose h2 { margin-top: 34px; }
.prose h3 { font-size: 17px; margin: 22px 0 6px; }
.prose p, .prose li { color: var(--muted); }
.prose .updated { font-size: 13px; color: var(--muted); }

/* contact form */
form.contact { display: grid; gap: 12px; max-width: 560px; }
form.contact label { font-size: 14px; font-weight: 600; }
form.contact input, form.contact textarea {
  width: 100%; font: inherit; color: var(--text); background: var(--panel);
  border: 1px solid var(--border); border-radius: 10px; padding: 11px 13px;
}
form.contact textarea { min-height: 140px; resize: vertical; }
form.contact button {
  justify-self: start; font: inherit; font-weight: 650; color: #fff; cursor: pointer;
  background: linear-gradient(90deg, var(--accent), color-mix(in srgb, var(--accent) 60%, var(--accent2)));
  border: 0; border-radius: 10px; padding: 12px 26px; box-shadow: 0 6px 24px var(--glow);
}

/* footer */
footer { border-top: 1px solid var(--border); margin-top: clamp(48px, 7vw, 84px); padding: 26px clamp(16px, 4vw, 40px) 40px; }
.footgrid { max-width: 1080px; margin: 0 auto; display: flex; flex-wrap: wrap; gap: 10px 26px; }
.footgrid a { color: var(--muted); font-size: 14px; }
.footgrid a:hover { color: var(--text); }
.legal { max-width: 1080px; margin: 14px auto 0; color: var(--muted); font-size: 13px; line-height: 1.6; }

/* product shot */
.shot { margin-top: 34px; }
.shot img {
  display: block; width: 100%; height: auto; border-radius: 14px;
  border: 1px solid var(--border); box-shadow: 0 18px 60px rgba(0,0,0,.35);
}
.shot figcaption { color: var(--muted); font-size: 13.5px; margin-top: 10px; text-align: center; }

/* accessibility: no motion for users who asked for none */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .hero .plane, .plane { animation: none !important; }
  .card { transition: none; }
}

/* compact nav on small screens: anchors are reachable by scrolling anyway */
@media (max-width: 640px) {
  nav .links a:not(.gh):not([href="/contact.html"]) { display: none; }
}

/* app-window frame for product shots */
.window { border-radius: 14px; overflow: hidden; border: 1px solid var(--border); box-shadow: 0 24px 70px rgba(0,0,0,.4); background: #f6f8fa; }
.winbar { display: flex; align-items: center; gap: 6px; padding: 10px 14px; background: var(--panel); border-bottom: 1px solid var(--border); }
.winbar i { width: 11px; height: 11px; border-radius: 50%; display: inline-block; }
.winbar i:nth-child(1) { background: #ff5f57; } .winbar i:nth-child(2) { background: #febc2e; } .winbar i:nth-child(3) { background: #28c840; }
.winbar span { margin-left: 8px; font-size: 12.5px; color: var(--muted); }
.window img { display: block; width: 100%; height: auto; border: 0; border-radius: 0; box-shadow: none; }

/* section eyebrows */
.eyebrow { display: block; font-size: 12.5px; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; margin-bottom: 8px;
  background: linear-gradient(90deg, var(--accent), var(--accent2)); -webkit-background-clip: text; background-clip: text; color: transparent; }