/* Prototype C — "Product Platform": тёмная тема, устройство в центре, табы по применениям */
:root{
  --bg:#070e16; --bg-2:#0d1822; --bg-3:#132230; --ink:#e9f4fa; --muted:#8fa7b8;
  --cyan:#03c4ef; --cyan-2:#42d3f0; --line:rgba(3,196,239,.22); --maxw:1200px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Arial,sans-serif;
  font-size:17px;line-height:1.65}
img{max-width:100%;height:auto;display:block}
a{color:var(--cyan-2);text-decoration:none}
.wrap{max-width:var(--maxw);margin:0 auto;padding:0 24px}
.eyebrow{font-size:12px;letter-spacing:.24em;text-transform:uppercase;color:var(--cyan);font-weight:700;margin:0 0 14px}

/* reveal on scroll */
.rv{opacity:0;transform:translateY(22px);transition:opacity .6s ease,transform .6s ease}
.rv.in{opacity:1;transform:none}
@media(prefers-reduced-motion:reduce){.rv{opacity:1;transform:none;transition:none}}

/* header */
.hdr{position:sticky;top:0;z-index:60;background:rgba(7,14,22,.85);backdrop-filter:blur(10px);
  border-bottom:1px solid rgba(255,255,255,.07)}
.hdr__in{display:flex;align-items:center;justify-content:space-between;gap:20px;min-height:70px}
.hdr__logo img{width:155px}
.nav{display:flex;gap:22px;list-style:none;margin:0;padding:0;align-items:center}
.nav a{color:var(--ink);font-size:12.5px;letter-spacing:.09em;text-transform:uppercase;font-weight:600;opacity:.85}
.nav a:hover{opacity:1;color:var(--cyan)}
.nav__sub{position:relative}
.nav__sub>a::after{content:"▾";margin-left:6px;font-size:10px}
.nav__sub ul{display:none;position:absolute;left:-16px;top:100%;background:var(--bg-3);list-style:none;margin:0;
  padding:8px 0;min-width:250px;border:1px solid var(--line);border-radius:0 0 12px 12px}
.nav__sub:hover ul,.nav__sub:focus-within ul{display:block}
.nav__sub ul a{display:block;padding:10px 20px;text-transform:none;letter-spacing:0;font-size:14px;font-weight:500}
.burger{display:none;background:none;border:0;color:var(--ink);font-size:24px;cursor:pointer}

/* hero */
.hero{position:relative;overflow:hidden;padding:96px 0 80px;text-align:center}
.hero>img.bg{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;opacity:.5}
.hero::after{content:"";position:absolute;inset:0;
  background:radial-gradient(ellipse at 50% 40%,rgba(7,14,22,.35),rgba(7,14,22,.96) 72%)}
.hero__in{position:relative;z-index:2}
.hero h1{font-size:clamp(46px,9vw,96px);font-weight:200;margin:0 0 20px;letter-spacing:.02em}
.hero h1 sup{font-size:.3em;vertical-align:super;color:var(--cyan)}
.hero p{max-width:900px;margin:0 auto;font-size:clamp(13px,1.5vw,17px);letter-spacing:.07em;
  text-transform:uppercase;color:#a9c9da;line-height:1.75}

/* device */
.device{padding:10px 0 90px;position:relative;z-index:3;margin-top:-20px}
/* картинка катетера идёт со своей светлой подложкой — рамку делаем прозрачной,
   иначе на тёмной теме получается «карточка в карточке» */
.device__frame{border-radius:22px;overflow:hidden;
  box-shadow:0 26px 70px rgba(0,0,0,.5),0 0 0 1px var(--line)}
.device__frame img{margin:0 auto;width:100%;max-width:1100px}
.caps{display:grid;grid-template-columns:repeat(5,1fr);gap:14px;margin-top:30px}
.cap{background:var(--bg-3);border:1px solid rgba(255,255,255,.07);border-radius:14px;padding:20px 18px;
  font-size:14.5px;line-height:1.5;transition:border-color .15s,transform .15s}
.cap:hover{border-color:var(--cyan);transform:translateY(-3px)}
.cap i{display:block;width:26px;height:2px;background:var(--cyan);margin-bottom:14px}

section{padding:88px 0}
h2{font-size:clamp(26px,3.4vw,38px);font-weight:400;margin:0 0 26px;letter-spacing:.01em}
h2 sup{font-size:.38em;vertical-align:super;color:var(--cyan)}
.mission p{margin:0 0 20px;text-align:justify;color:#c2d6e2;max-width:960px}

/* tabs */
.tabs{border-top:1px solid rgba(255,255,255,.08);background:var(--bg-2)}
.tabbar{display:flex;gap:8px;flex-wrap:wrap;margin-bottom:34px}
.tab{background:transparent;border:1px solid rgba(255,255,255,.14);color:var(--ink);border-radius:999px;
  padding:12px 24px;font-size:13px;font-weight:600;letter-spacing:.06em;text-transform:uppercase;cursor:pointer}
.tab[aria-selected="true"]{background:var(--cyan);border-color:var(--cyan);color:#062133}
.panel{display:none;grid-template-columns:300px 1fr;gap:44px;align-items:center}
.panel.on{display:grid}
.panel img{width:260px;border-radius:16px;border:1px solid var(--line)}
.panel h3{margin:0 0 16px;font-size:23px;font-weight:600}
.panel p{margin:0 0 16px;color:#c2d6e2;text-align:justify}
.panel p:last-child{margin:0}
.panel .tagline{color:var(--cyan-2);font-size:15px;letter-spacing:.03em}

/* audience */
.cols{display:grid;grid-template-columns:1fr 1fr;gap:26px}
.box{background:var(--bg-2);border:1px solid rgba(255,255,255,.08);border-radius:18px;padding:40px;
  transition:border-color .15s}
.box:hover{border-color:var(--cyan)}
.box h3{margin:0 0 16px;font-size:21px;font-weight:600}
.box p{margin:0;text-align:justify;color:#c2d6e2}

/* footer */
.ftr{background:#04090f;color:var(--muted);padding:56px 0 30px;font-size:15px;border-top:1px solid rgba(255,255,255,.07)}
.ftr__in{display:grid;grid-template-columns:1.2fr 1fr 1fr;gap:30px}
.ftr img{width:150px;margin-bottom:18px}
.ftr__cr{margin-top:36px;padding-top:20px;border-top:1px solid rgba(255,255,255,.08);font-size:13px;color:#5f7788}

@media(max-width:1080px){.caps{grid-template-columns:repeat(2,1fr)}}
@media(max-width:980px){
  .burger{display:block}
  .nav{display:none;position:absolute;left:0;right:0;top:70px;background:var(--bg-3);
    flex-direction:column;align-items:flex-start;gap:0;padding:12px 24px 20px}
  .nav.open{display:flex}
  .nav>li{width:100%;padding:10px 0}
  .nav__sub ul{display:block;position:static;border:0;padding:6px 0 0 14px}
  .panel.on,.cols,.ftr__in{grid-template-columns:1fr;gap:26px}
  .panel img{width:200px}
  section{padding:56px 0}
  .device__frame{padding:18px}
}
@media(max-width:560px){.caps{grid-template-columns:1fr}}