:root {
  --teal: #0e9f8e;
  --teal-dark: #08606e;
  --ink: #0f2a2a;
  --muted: #4f6b6a;
  --bg: #f6fbfa;
  --card: #ffffff;
  --line: #dcebe8;
  --radius: 18px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e6f4f2;
    --muted: #9db8b5;
    --bg: #0c1a1a;
    --card: #132625;
    --line: #234140;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.6;
}
a { color: var(--teal); }
img { max-width: 100%; display: block; }
.wrap { width: min(1080px, 100% - 32px); margin: 0 auto; }

/* header */
header.top {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
header.top .wrap { display: flex; align-items: center; gap: 12px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font-weight: 800; font-size: 1.25rem; }
.brand img { width: 36px; height: 36px; border-radius: 10px; }
nav.links { margin-left: auto; display: flex; gap: 18px; flex-wrap: wrap; }
nav.links a { color: var(--muted); text-decoration: none; font-weight: 600; font-size: .95rem; }
nav.links a:hover { color: var(--teal); }
@media (max-width: 640px) { nav.links .hide-sm { display: none; } }

/* hero */
.hero {
  background: linear-gradient(135deg, #0e9f8e 0%, #08606e 100%);
  color: #fff;
  padding: 72px 0 84px;
  overflow: hidden;
}
.hero .wrap { display: grid; grid-template-columns: 1.1fr .9fr; gap: 40px; align-items: center; }
@media (max-width: 820px) { .hero .wrap { grid-template-columns: 1fr; } .phone { display: none; } }
.hero h1 { font-size: clamp(2.2rem, 5vw, 3.4rem); line-height: 1.1; margin: 0 0 16px; }
.hero p.lead { font-size: 1.15rem; opacity: .92; margin: 0 0 28px; max-width: 34em; }
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  background: #111; color: #fff; text-decoration: none;
  padding: 12px 22px; border-radius: 14px; font-weight: 700;
  border: 1px solid rgba(255,255,255,.25);
}
.btn small { display: block; font-weight: 500; font-size: .7rem; opacity: .8; line-height: 1; }
.btn .big { line-height: 1.1; }
.btn.secondary { background: rgba(255,255,255,.14); }
.cta { display: flex; gap: 12px; flex-wrap: wrap; }
.badges { margin-top: 24px; display: flex; gap: 16px; flex-wrap: wrap; font-size: .9rem; opacity: .92; }

/* phone mock */
.phone {
  justify-self: center;
  width: 270px; height: 540px; border-radius: 40px;
  background: #0b1717; padding: 14px;
  box-shadow: 0 30px 60px rgba(0,0,0,.35);
  transform: rotate(3deg);
}
.screen { width: 100%; height: 100%; border-radius: 28px; background: #10201d; overflow: hidden; display: flex; flex-direction: column; }
.screen .bar { background: #16302c; color: #e6f4f2; padding: 14px 16px; font-weight: 700; font-size: .95rem; }
.screen .msgs { flex: 1; padding: 12px; display: flex; flex-direction: column; gap: 8px; }
.bubble { max-width: 78%; padding: 8px 12px; border-radius: 16px; font-size: .85rem; color: #e6f4f2; background: #24403b; }
.bubble.me { align-self: flex-end; background: var(--teal); color: #fff; border-bottom-right-radius: 4px; }
.bubble.them { border-bottom-left-radius: 4px; }
.sticker { font-size: 3rem; align-self: flex-end; animation: bob 2.4s ease-in-out infinite; }
.voice { display: flex; align-items: center; gap: 8px; }
.voice span { display: inline-block; width: 3px; background: #fff; border-radius: 2px; }
@keyframes bob { 50% { transform: translateY(-6px) rotate(-6deg); } }
@media (prefers-reduced-motion: reduce) { .sticker { animation: none; } }

/* sections */
section { padding: 72px 0; }
section h2 { font-size: clamp(1.6rem, 3.5vw, 2.2rem); margin: 0 0 8px; }
section p.sub { color: var(--muted); margin: 0 0 32px; max-width: 46em; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px; }
.card .ico { font-size: 1.8rem; }
.card h3 { margin: 8px 0 6px; font-size: 1.1rem; }
.card p { margin: 0; color: var(--muted); font-size: .95rem; }
.alt { background: var(--card); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.steps { counter-reset: s; display: grid; gap: 14px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.steps li { list-style: none; counter-increment: s; background: var(--bg); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 20px 20px 64px; position: relative; }
.steps li::before { content: counter(s); position: absolute; left: 18px; top: 18px; width: 32px; height: 32px; border-radius: 50%; background: var(--teal); color: #fff; display: grid; place-items: center; font-weight: 800; }
.steps { padding: 0; margin: 0; }
.faq details { background: var(--card); border: 1px solid var(--line); border-radius: 14px; padding: 14px 18px; margin-bottom: 10px; }
.faq summary { cursor: pointer; font-weight: 700; }
.faq p { color: var(--muted); margin: 10px 0 0; }

/* document pages */
.doc { padding: 48px 0 72px; }
.doc .wrap { max-width: 820px; }
.doc h1 { font-size: clamp(1.8rem, 4vw, 2.4rem); margin: 0 0 4px; }
.doc .updated { color: var(--muted); margin: 0 0 28px; }
.doc h2 { font-size: 1.3rem; margin: 32px 0 8px; }
.doc li { margin: 6px 0; }
.note { background: color-mix(in srgb, var(--teal) 12%, var(--card)); border: 1px solid var(--line); border-radius: 14px; padding: 16px 18px; }

/* footer */
footer { border-top: 1px solid var(--line); padding: 32px 0; color: var(--muted); font-size: .9rem; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 12px 24px; align-items: center; }
footer nav { display: flex; flex-wrap: wrap; gap: 16px; margin-left: auto; }
footer a { color: var(--muted); }

/* demo video */
.video-frame {
  border-radius: 22px; overflow: hidden; background: #062f33;
  box-shadow: 0 24px 60px rgba(8, 96, 110, .25);
  border: 1px solid var(--line);
  aspect-ratio: 16 / 9;
}
.video-frame video { width: 100%; height: 100%; display: block; }