:root {
  color-scheme: dark;
  --ink: #0b0d0c;
  --ink-soft: #111411;
  --panel: #171a17;
  --panel-2: #1e221e;
  --line: #343b34;
  --line-bright: #535e53;
  --paper: #ede9df;
  --muted: #a6ada4;
  --amber: #e5aa42;
  --amber-bright: #f5c260;
  --blue: #48a7d1;
  --green: #62c56f;
  --cream: #ead9aa;
  --max: 1360px;
  --pad: clamp(20px, 4vw, 64px);
  --display: "Arial Narrow", "Roboto Condensed", "Helvetica Neue", Arial, sans-serif;
  --sans: Inter, "Segoe UI", Helvetica, Arial, sans-serif;
  --mono: "Cascadia Mono", "SFMono-Regular", Consolas, monospace;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; }
body {
  margin: 0;
  min-width: 320px;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 20;
  opacity: .035;
  background-image: radial-gradient(circle at center, #fff 0 .55px, transparent .75px);
  background-size: 5px 5px;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
code { font-family: var(--mono); }
[data-language="en"] [data-lang="ru"], [data-language="ru"] [data-lang="en"] { display: none !important; }
.shell { width: min(100% - (2 * var(--pad)), var(--max)); margin-inline: auto; }
.sr-only, .skip-link:not(:focus) { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }
.skip-link:focus { position: fixed; z-index: 100; top: 10px; left: 10px; padding: 10px 14px; background: var(--amber); color: var(--ink); }
:focus-visible { outline: 2px solid var(--amber-bright); outline-offset: 4px; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  background: color-mix(in srgb, var(--ink) 88%, transparent);
  backdrop-filter: blur(18px);
  border-bottom: 1px solid color-mix(in srgb, var(--line) 70%, transparent);
}
.header-inner { height: 74px; display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 28px; }
.brand { justify-self: start; display: inline-flex; align-items: center; gap: 11px; font-family: var(--display); font-weight: 900; letter-spacing: .12em; font-size: 1rem; }
.brand-pulse { width: 8px; height: 8px; background: var(--amber); border-radius: 50%; box-shadow: 0 0 0 5px color-mix(in srgb, var(--amber) 12%, transparent); }
.site-nav { display: flex; gap: clamp(18px, 2.4vw, 38px); color: var(--muted); font-size: .8rem; letter-spacing: .08em; text-transform: uppercase; }
.site-nav a, .footer-inner a { transition: color .2s ease; }
.site-nav a:hover, .footer-inner a:hover { color: var(--paper); }
.language-toggle { justify-self: end; border: 0; padding: 8px 0; color: #666d66; background: none; cursor: pointer; font-family: var(--mono); font-size: .75rem; letter-spacing: .08em; }
.language-toggle .language-active { color: var(--amber); }
.nav-toggle { display: none; border: 0; background: none; width: 42px; height: 42px; padding: 11px; cursor: pointer; }
.nav-toggle > span[aria-hidden] { display: block; height: 1px; background: var(--paper); margin: 6px 0; }

.hero { min-height: min(880px, calc(100svh - 74px)); display: grid; grid-template-columns: .82fr 1.18fr; gap: clamp(34px, 7vw, 100px); align-items: center; padding-block: clamp(70px, 9vw, 130px); overflow: hidden; }
.eyebrow, .section-index { margin: 0 0 24px; color: var(--amber); font-family: var(--mono); font-size: .72rem; text-transform: uppercase; letter-spacing: .16em; }
.hero h1, .catalog-intro h2, .engineering h2, .downloads h2, .contact h2 { margin: 0; font-family: var(--display); font-weight: 800; line-height: .9; text-transform: uppercase; letter-spacing: -.05em; }
.hero h1 { font-size: clamp(3.6rem, 7vw, 7.2rem); }
.hero h1 em { color: var(--amber); font-style: normal; }
.hero-copy, .hero-stage { min-width: 0; }
.hero-lede { max-width: 650px; margin: 34px 0 0; color: #bcc2ba; font-size: clamp(1.05rem, 1.5vw, 1.3rem); line-height: 1.55; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 38px; }
.button { display: inline-flex; align-items: center; justify-content: center; gap: 20px; min-height: 52px; padding: 0 22px; border: 1px solid var(--line-bright); font-size: .82rem; font-weight: 700; letter-spacing: .06em; text-transform: uppercase; transition: transform .2s ease, background .2s ease, border-color .2s ease; }
.button:hover { transform: translateY(-2px); border-color: var(--paper); }
.button-primary { background: var(--amber); border-color: var(--amber); color: #16130d; }
.button-primary:hover { background: var(--amber-bright); border-color: var(--amber-bright); }
.button-quiet { color: var(--muted); }

.hero-stage { position: relative; min-height: 565px; isolation: isolate; }
.stage-grid { position: absolute; inset: 4% -30% -7% 2%; z-index: -1; opacity: .52; background-image: linear-gradient(var(--line) 1px, transparent 1px), linear-gradient(90deg, var(--line) 1px, transparent 1px); background-size: 46px 46px; mask-image: linear-gradient(to bottom, transparent, #000 18%, #000 78%, transparent); transform: perspective(800px) rotateY(-9deg) rotateX(5deg); }
.device { position: absolute; margin: 0; overflow: hidden; border: 1px solid #535953; border-radius: 8px; background: #151715; box-shadow: 0 30px 80px #000b; }
.device img { width: 100%; height: auto; }
.device-system { width: 86%; right: 0; top: 5%; transform: rotate(1.4deg); }
.device-optivalve { width: 67%; left: 2%; top: 53%; transform: rotate(-2.5deg); box-shadow: 0 24px 65px #000c; }
.stage-readout { position: absolute; right: 4%; bottom: 2%; display: flex; align-items: center; gap: 8px; color: #747c74; font-family: var(--mono); font-size: .64rem; letter-spacing: .05em; }
.stage-readout i { width: 16px; height: 1px; background: #3d443d; }

.section-rule { border-top: 1px solid var(--line); }
.catalog-intro { display: grid; grid-template-columns: 1fr 1fr; gap: 50px; padding-block: clamp(80px, 10vw, 140px); align-items: end; }
.catalog-intro h2, .engineering h2, .downloads h2, .contact h2 { font-size: clamp(2.7rem, 5.5vw, 5.6rem); }
.section-lede, .downloads-head > p { max-width: 580px; margin: 0 0 2px; color: var(--muted); font-size: clamp(1.05rem, 1.5vw, 1.25rem); }

.product { position: relative; display: grid; grid-template-columns: 42px minmax(280px, .78fr) minmax(480px, 1.42fr); gap: clamp(24px, 4vw, 64px); align-items: center; padding-block: clamp(70px, 9vw, 126px); border-top: 1px solid var(--line); }
.product-number { align-self: start; padding-top: 8px; color: #626a62; font-family: var(--mono); font-size: .75rem; }
.product-copy { max-width: 470px; }
.product-kicker { display: flex; justify-content: space-between; gap: 20px; color: var(--muted); font-family: var(--mono); font-size: .68rem; letter-spacing: .11em; }
.product h3 { margin: 20px 0 0; font-family: var(--display); font-size: clamp(3rem, 5vw, 5.3rem); line-height: .95; letter-spacing: -.05em; text-transform: uppercase; }
.product-subtitle { margin: 8px 0 27px !important; color: var(--amber) !important; font-family: var(--mono); font-size: .78rem !important; letter-spacing: .11em; text-transform: uppercase; }
.product-copy > p:not(.product-subtitle) { color: #c2c7bf; font-size: 1.02rem; }
.feature-list { list-style: none; margin: 28px 0 34px; padding: 0; border-top: 1px solid var(--line); }
.feature-list li { position: relative; padding: 11px 0 11px 21px; border-bottom: 1px solid var(--line); color: var(--muted); font-size: .83rem; }
.feature-list li::before { content: "+"; position: absolute; left: 0; color: var(--amber); font-family: var(--mono); }
.text-link { display: inline-flex; align-items: center; gap: 24px; padding-bottom: 7px; border-bottom: 1px solid var(--amber); color: var(--paper); font-size: .78rem; font-weight: 700; letter-spacing: .07em; text-transform: uppercase; }
.text-link span[aria-hidden] { color: var(--amber); transition: transform .2s ease; }
.text-link:hover span[aria-hidden] { transform: translate(3px, 3px); }
.product-visual { min-width: 0; }
.media-carousel {
  --carousel-accent: var(--amber);
  --carousel-active-text: var(--ink);
  padding: clamp(12px, 1.8vw, 22px);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--ink-soft);
  box-shadow: 0 24px 70px #0007;
}
.carousel-toolbar { display: flex; align-items: center; justify-content: space-between; gap: 16px; margin-bottom: 13px; }
.carousel-tabs { min-width: 0; display: flex; flex-wrap: wrap; gap: 6px; }
.carousel-tabs button, .carousel-nav button {
  border: 1px solid var(--line);
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-family: var(--mono);
  font-size: .65rem;
  letter-spacing: .07em;
  text-transform: uppercase;
}
.carousel-tabs button { min-height: 33px; padding: 6px 11px; }
.carousel-tabs button[aria-selected="true"] { border-color: var(--carousel-accent); background: var(--carousel-accent); color: var(--carousel-active-text); }
.carousel-nav { flex: none; display: flex; align-items: center; gap: 7px; }
.carousel-nav button { width: 33px; height: 33px; padding: 0; font-size: .83rem; }
.carousel-nav button:hover { border-color: var(--carousel-accent); color: var(--carousel-accent); }
.carousel-nav output { min-width: 49px; color: #6f786f; font-family: var(--mono); font-size: .58rem; text-align: center; letter-spacing: .08em; }
.carousel-stage { position: relative; min-width: 0; overflow: hidden; touch-action: pan-y; }
.carousel-panel { width: 100%; margin: 0; overflow: hidden; }
.carousel-panel:not([hidden]) { animation: carousel-in .24s ease both; }
.carousel-panel[hidden] { display: none; }
.image-panel { background: #151715; }
.image-panel img { width: 100%; height: auto; }
@keyframes carousel-in { from { opacity: 0; transform: translateX(10px); } to { opacity: 1; transform: translateX(0); } }

.system68-carousel .carousel-stage { background: #161915; }
.system68-carousel .image-panel { aspect-ratio: 1.74; }
.system68-carousel .image-panel img { width: 100%; height: 100%; object-fit: contain; }
.system-flow-panel { aspect-ratio: 1.74; display: grid; grid-template-rows: auto 1fr auto; gap: clamp(12px, 2vw, 24px); padding: clamp(16px, 2.6vw, 32px); background: #111511; border: 1px solid #394039; }
.diagram-heading { display: grid; gap: 5px; }
.diagram-heading strong { font-family: var(--display); font-size: clamp(1rem, 2vw, 1.55rem); line-height: 1; text-transform: uppercase; letter-spacing: -.02em; }
.system-flow { display: grid; grid-template-columns: 1.25fr .32fr .48fr .32fr 1fr; gap: clamp(7px, 1.2vw, 15px); align-items: center; }
.channel-bank, .bus-bank { display: grid; gap: 7px; }
.flow-chip { min-width: 0; min-height: 57px; display: grid; grid-template-columns: auto 1fr auto; grid-template-rows: auto auto; align-items: center; gap: 2px 10px; padding: 8px 10px; border: 1px solid #454c45; background: #1a1e1a; }
.flow-chip small { color: #747d74; font-family: var(--mono); font-size: .56rem; }
.flow-chip strong { font-size: clamp(.63rem, 1vw, .78rem); text-transform: uppercase; }
.flow-chip span { grid-column: 3; grid-row: 1 / 3; color: var(--amber); font-family: var(--mono); font-size: .54rem; text-transform: uppercase; }
.flow-chip > i { grid-column: 1 / 3; height: 2px; overflow: hidden; background: linear-gradient(90deg, #596159 0 17%, var(--amber) 17% 25%, #596159 25% 43%, var(--amber) 43% 57%, #596159 57% 76%, var(--amber) 76% 82%, #596159 82%); opacity: .7; }
.flow-chip-bus { grid-template-columns: auto 1fr; min-height: 82px; border-color: #66522c; }
.flow-chip-bus span { grid-column: 1 / -1; grid-row: auto; }
.flow-sum { aspect-ratio: 1; display: grid; place-items: center; align-content: center; gap: 0; border: 1px solid var(--amber); border-radius: 50%; background: #242018; box-shadow: 0 0 0 5px #e5aa4212; }
.flow-sum small, .flow-sum span { color: #8f968f; font-family: var(--mono); font-size: .48rem; letter-spacing: .08em; }
.flow-sum strong { color: var(--amber); font-family: Georgia, serif; font-size: clamp(1.2rem, 2.8vw, 2.4rem); font-weight: 400; line-height: .9; }
.flow-wire { display: grid; place-items: center; gap: 5px; color: #818a81; font-family: var(--mono); font-size: .46rem; }
.flow-wire i { width: 100%; height: 1px; background: var(--amber); position: relative; }
.flow-wire i::after { content: ""; position: absolute; right: -1px; top: -3px; width: 6px; height: 6px; border-top: 1px solid var(--amber); border-right: 1px solid var(--amber); transform: rotate(45deg); }
.diagram-foot { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; padding-top: 11px; border-top: 1px solid #343b34; color: #969e96; font-size: .64rem; }
.diagram-foot > span { display: flex; gap: 8px; }
.diagram-foot b { color: var(--amber); font-family: var(--mono); font-size: .55rem; }

.broadcurve-carousel { --carousel-accent: var(--cream); --carousel-active-text: #1b1d1d; background: #2f3940; border-color: #657179; color: #f2e8cf; }
.broadcurve-carousel .carousel-tabs button, .broadcurve-carousel .carousel-nav button { border-color: #71808a; color: #cbd1d4; }
.broadcurve-carousel .carousel-tabs button[aria-selected="true"] { color: #1b1d1d; }
.broadcurve-carousel .carousel-nav output { color: #aeb8bd; }
.broadcurve-carousel .image-panel, .broadcurve-carousel .chart-panel { aspect-ratio: 98 / 43; }
.broadcurve-carousel .image-panel { background: #151a1d; }
.broadcurve-carousel .image-panel img { width: 100%; height: 100%; object-fit: contain; }
.chart-panel, .optivalve-chart-panel { display: grid; grid-template-rows: auto 1fr auto auto; gap: clamp(5px, 1vw, 10px); padding: clamp(10px, 1.7vw, 20px); }
.chart-panel { background: #2f3940; border: 1px solid #71808a; }
.chart-head { display: flex; align-items: end; justify-content: space-between; gap: 16px; }
.chart-head strong { font-family: var(--display); font-size: clamp(.84rem, 1.65vw, 1.35rem); line-height: 1; text-align: right; text-transform: uppercase; letter-spacing: -.02em; }
.visual-label { color: #b8c0c4; font-family: var(--mono); font-size: .65rem; letter-spacing: .1em; text-transform: uppercase; }
.curve-frame { position: relative; min-height: 0; border: 1px solid #79848a; background: #273138; }
.curve-frame::after { content: "dB"; position: absolute; top: 10px; left: 12px; color: #9aa6ad; font-family: var(--mono); font-size: .65rem; }
.response-chart { display: block; width: 100%; height: 100%; }
.curve-scale { display: flex; justify-content: space-between; padding: 8px 1px 0; color: #aeb8bd; font-family: var(--mono); font-size: .62rem; }
.chart-note { margin: 0; color: #b8c1c4; font-size: .66rem; line-height: 1.35; }

.optivalve-carousel { --carousel-accent: #d5b25c; background: #9b9a95; border-color: #686d68; }
.optivalve-carousel .carousel-tabs button, .optivalve-carousel .carousel-nav button { border-color: #4e534e; color: #282c28; }
.optivalve-carousel .carousel-nav output { color: #424742; }
.optivalve-carousel .image-panel, .optivalve-carousel .optivalve-chart-panel { aspect-ratio: 92 / 43; }
.optivalve-carousel .image-panel { background: #aaa8a3; }
.optivalve-carousel .image-panel img { width: 100%; height: 100%; object-fit: contain; }
.optivalve-chart-panel { background: #e4e0d5; border: 1px solid #696c66; color: #22251f; }
.optivalve-chart-panel .visual-label, .optivalve-chart-panel .chart-note { color: #656960; }
.dynamics-frame { position: relative; min-height: 0; overflow: hidden; border: 1px solid #8d8d82; background: #d8d5cb; }
.chart-legend { display: flex; flex-wrap: wrap; gap: 14px; font-family: var(--mono); font-size: .55rem; text-transform: uppercase; letter-spacing: .04em; }
.chart-legend span { display: inline-flex; align-items: center; gap: 5px; }
.chart-legend i { width: 13px; height: 2px; background: #777; }
.legend-input i { background: #7f8581; }
.legend-output i, .legend-comp i { background: #b17a1b; }
.legend-gr i, .legend-limit i { background: #222721; }

.racklink-carousel { --carousel-accent: var(--blue); --carousel-active-text: #071018; background: #101820; border-color: #34414c; }
.racklink-carousel .carousel-tabs button, .racklink-carousel .carousel-nav button { border-color: #45515c; color: #aab6bf; }
.racklink-carousel .carousel-tabs button[aria-selected="true"] { color: #071018; }
.racklink-carousel .carousel-nav output { color: #758491; }
.racklink-ui-panel, .racklink-diagram-panel { aspect-ratio: 16 / 9; }
.racklink-ui-panel { background: #20242a; }
.racklink-ui-panel img { width: 100%; height: 100%; object-fit: contain; }
.racklink-diagram-panel { display: grid; grid-template-rows: auto 1fr auto; padding: clamp(14px, 2.2vw, 28px); background: #101820; color: var(--paper); border: 1px solid #34414c; }
.racklink-brandline { display: flex; align-items: center; gap: 20px; padding-bottom: 26px; border-bottom: 1px solid #34414c; }
.racklink-brandline img { width: 76px; height: 76px; }
.racklink-brandline div { display: grid; gap: 3px; }
.racklink-brandline span { font-family: var(--display); font-size: 2rem; font-weight: 800; letter-spacing: -.03em; }
.racklink-brandline small { color: var(--blue); font-family: var(--mono); font-size: .67rem; letter-spacing: .12em; }
.signal-route { display: grid; grid-template-columns: 1fr .6fr 1.15fr .6fr 1fr; align-items: center; gap: 10px; padding: clamp(40px, 6vw, 80px) 0; }
.route-node { min-height: 116px; padding: 15px; border: 1px solid #45515c; display: flex; flex-direction: column; justify-content: space-between; background: #17212a; }
.route-node small { color: #72808c; font-family: var(--mono); font-size: .62rem; }
.route-node strong { font-size: .9rem; }
.route-node span { color: #93a1ad; font-size: .66rem; text-transform: uppercase; letter-spacing: .06em; }
.route-node-accent { border-color: var(--blue); box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--blue) 30%, transparent); }
.route-wire { display: grid; align-items: center; justify-items: center; color: var(--blue); font-family: var(--mono); font-size: .57rem; }
.route-wire i { display: block; width: 100%; height: 1px; background: var(--blue); }
.route-foot { display: flex; align-items: center; justify-content: flex-end; gap: 8px; margin: 0; color: #95a1aa; font-family: var(--mono); font-size: .65rem; text-transform: uppercase; }
.status-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--green); box-shadow: 0 0 0 4px color-mix(in srgb, var(--green) 13%, transparent); }
.multi-device-panel { gap: 14px; }
.multi-device-route { min-height: 0; display: grid; grid-template-columns: .8fr .8fr 1.25fr; align-items: center; gap: clamp(20px, 4vw, 55px); }
.multi-source, .multi-hub { min-height: 116px; display: grid; place-items: center; align-content: center; gap: 3px; border: 1px solid #45515c; background: #17212a; text-align: center; }
.multi-source small, .multi-source span, .multi-hub span, .multi-targets small { color: #84939f; font-family: var(--mono); font-size: .55rem; text-transform: uppercase; letter-spacing: .06em; }
.multi-source strong, .multi-hub strong { text-transform: uppercase; }
.multi-hub { position: relative; border-color: var(--blue); }
.multi-hub::before, .multi-hub::after { content: ""; position: absolute; top: 50%; width: clamp(20px, 4vw, 55px); height: 1px; background: var(--blue); }
.multi-hub::before { right: 100%; }
.multi-hub::after { left: 100%; }
.multi-hub img { width: 34px; height: 34px; }
.multi-targets { display: grid; gap: 9px; position: relative; }
.multi-targets::before { content: ""; position: absolute; left: calc(clamp(20px, 4vw, 55px) * -1); top: 16%; bottom: 16%; width: 1px; background: var(--blue); }
.multi-targets > div { min-height: 54px; display: grid; grid-template-columns: 18px 1fr; align-items: center; border: 1px solid #45515c; background: #17212a; }
.multi-targets > div > i { align-self: stretch; border-right: 1px solid #45515c; background: linear-gradient(180deg, #17212a, #23313d); }
.multi-targets > div > span { display: grid; padding: 8px 12px; }
.multi-targets strong { font-size: .72rem; }

.engineering { margin-top: clamp(50px, 8vw, 110px); padding-block: clamp(90px, 11vw, 150px); background: var(--paper); color: #171916; }
.engineering-grid { display: grid; grid-template-columns: 1fr 1fr; gap: clamp(50px, 8vw, 120px); }
.engineering .section-index { color: #986715; }
.engineering-copy p:last-child { max-width: 610px; margin: 34px 0 0; color: #555a53; font-size: 1.12rem; }
.engineering-metrics { display: grid; grid-template-columns: 1fr 1fr; border-top: 1px solid #b8b8ae; border-left: 1px solid #b8b8ae; }
.engineering-metrics article { min-height: 175px; display: flex; flex-direction: column; justify-content: space-between; padding: 22px; border-right: 1px solid #b8b8ae; border-bottom: 1px solid #b8b8ae; }
.engineering-metrics strong { font-family: var(--display); font-size: clamp(2.2rem, 4vw, 4.2rem); letter-spacing: -.04em; }
.engineering-metrics span { color: #656a62; font-family: var(--mono); font-size: .68rem; text-transform: uppercase; letter-spacing: .08em; }
.engineering-path { grid-column: 1 / -1; display: grid; grid-template-columns: auto 1fr auto 1fr auto 1fr auto; align-items: center; margin-top: 25px; }
.engineering-path > span { display: grid; gap: 5px; min-width: 110px; }
.engineering-path b { color: #986715; font-family: var(--mono); font-size: .62rem; }
.engineering-path span span { font-size: .72rem; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; }
.engineering-path i { height: 1px; margin: 0 15px; background: #999b92; }

.downloads { padding-block: clamp(90px, 11vw, 150px); }
.downloads-head { display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: end; padding-top: clamp(70px, 8vw, 110px); padding-bottom: 60px; }
.download-list { border-top: 1px solid var(--line-bright); }
.download-row { position: relative; display: grid; grid-template-columns: minmax(220px, 1fr) minmax(220px, auto); gap: 28px; align-items: center; padding: 25px 0; border-bottom: 1px solid var(--line); }
.download-product { display: flex; align-items: center; gap: 18px; }
.download-index { color: #626a62; font-family: var(--mono); font-size: .62rem; }
.download-product h3 { margin: 0; font-family: var(--display); font-size: 1.45rem; letter-spacing: -.02em; text-transform: uppercase; }
.download-product div > span { color: var(--muted); font-family: var(--mono); font-size: .65rem; }
.download-menu { position: relative; justify-self: end; width: 220px; }
.download-menu > summary { list-style: none; cursor: pointer; }
.download-menu > summary::-webkit-details-marker { display: none; }
.download-button { display: flex; align-items: center; justify-content: space-between; gap: 18px; width: 100%; padding: 12px 14px; border: 1px solid var(--line-bright); font-size: .67rem; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; transition: color .2s, background .2s, border-color .2s; }
.download-button:hover, .download-menu[open] .download-button { background: var(--amber); border-color: var(--amber); color: var(--ink); }
.download-arrow { transition: transform .2s ease; }
.download-menu[open] .download-arrow { transform: rotate(180deg); }
.download-options { position: absolute; z-index: 15; top: calc(100% + 8px); right: 0; width: max(100%, 290px); border: 1px solid var(--line-bright); background: #111411; box-shadow: 0 18px 45px #000b; }
.download-option { display: flex; align-items: center; justify-content: space-between; gap: 22px; padding: 14px; border-bottom: 1px solid var(--line); }
.download-option:last-child { border-bottom: 0; }
.download-option > span:first-child { display: grid; gap: 2px; }
.download-option strong { font-size: .78rem; }
.download-option small { color: var(--muted); font-family: var(--mono); font-size: .61rem; white-space: nowrap; }
a.download-option { transition: color .2s, background .2s; }
a.download-option:hover, a.download-option:focus-visible { background: var(--panel-2); color: var(--amber-bright); }
.download-option-unavailable { color: #747b74; opacity: .62; cursor: not-allowed; }
.file-verification { margin-top: 34px; border: 1px solid var(--line); background: #0d100e; }
.file-verification > summary { list-style: none; display: flex; justify-content: space-between; gap: 20px; padding: 17px 20px; cursor: pointer; color: #9ca49b; font-size: .73rem; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; }
.file-verification > summary::-webkit-details-marker { display: none; }
.file-verification > summary > span[aria-hidden] { color: var(--amber); font-family: var(--mono); font-size: 1rem; transition: transform .2s; }
.file-verification[open] > summary > span[aria-hidden] { transform: rotate(45deg); }
.verification-content { padding: 3px 20px 20px; color: var(--muted); font-size: .8rem; }
.verification-content > p { max-width: 760px; margin: 0 0 18px; }
.verification-list { border-top: 1px solid var(--line); }
.verification-list > div { display: grid; grid-template-columns: minmax(190px, .8fr) minmax(240px, 1.6fr) auto; gap: 16px; align-items: center; padding: 12px 0; border-bottom: 1px solid var(--line); }
.verification-list strong { font-size: .72rem; }
.verification-list code { min-width: 0; overflow: hidden; text-overflow: ellipsis; color: #858e85; font-size: .62rem; white-space: nowrap; }
.verification-list button { border: 0; padding: 0; background: none; color: var(--amber); cursor: pointer; font-size: .63rem; text-transform: uppercase; }
.install-notes { margin-top: 52px; border-top: 1px solid var(--line); }
.install-notes details { border-bottom: 1px solid var(--line); }
.install-notes summary { list-style: none; display: flex; justify-content: space-between; gap: 20px; padding: 20px 0; cursor: pointer; font-size: .83rem; font-weight: 700; text-transform: uppercase; letter-spacing: .05em; }
.install-notes summary::-webkit-details-marker { display: none; }
.install-notes summary > span[aria-hidden] { color: var(--amber); font-family: var(--mono); font-size: 1rem; transition: transform .2s; }
.install-notes details[open] summary > span[aria-hidden] { transform: rotate(45deg); }
.details-content { max-width: 850px; padding: 0 0 22px; color: var(--muted); }
.details-content code { color: #d4d8d1; font-size: .83em; overflow-wrap: anywhere; }

.contact { padding-block: clamp(100px, 13vw, 180px); background: var(--amber); color: #16130d; }
.contact .section-index { color: #6b4c14; }
.contact-inner { display: grid; grid-template-columns: 1.15fr .85fr; column-gap: clamp(50px, 8vw, 120px); align-items: end; }
.contact-inner .section-index { grid-column: 1 / -1; }
.contact h2 { max-width: 850px; }
.contact-inner > p:not(.section-index) { max-width: 540px; margin: 0 0 12px; color: #5b451d; font-size: 1.05rem; }
.email-copy { grid-column: 2; justify-self: start; margin-top: 30px; padding: 0 0 8px; display: grid; gap: 3px; border: 0; border-bottom: 2px solid #16130d; background: none; color: #16130d; text-align: left; cursor: pointer; }
.email-copy > span { font-family: var(--display); font-size: clamp(1.6rem, 3vw, 3rem); font-weight: 800; letter-spacing: -.04em; }
.email-copy small { font-family: var(--mono); font-size: .62rem; text-transform: uppercase; letter-spacing: .08em; }
.site-footer { border-top: 1px solid var(--line); }
.legal-note { padding-top: 30px; max-width: 980px; color: #666e66; font-size: .68rem; line-height: 1.55; }
.footer-inner { min-height: 92px; display: flex; align-items: center; justify-content: space-between; gap: 30px; color: #757d75; font-family: var(--mono); font-size: .65rem; text-transform: uppercase; letter-spacing: .08em; }
.footer-inner a { color: var(--paper); display: flex; gap: 12px; }
.toast { position: fixed; left: 50%; bottom: 28px; z-index: 60; transform: translate(-50%, 20px); padding: 11px 16px; background: var(--paper); color: var(--ink); font-family: var(--mono); font-size: .7rem; text-transform: uppercase; letter-spacing: .06em; opacity: 0; pointer-events: none; transition: opacity .2s, transform .2s; box-shadow: 0 10px 40px #0008; }
.toast.visible { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 1050px) {
  .hero { grid-template-columns: 1fr; min-height: 0; }
  .hero-copy { max-width: 760px; }
  .hero-stage { min-height: 520px; width: min(850px, 100%); margin-inline: auto; }
  .product { grid-template-columns: 32px 1fr; }
  .product-visual { grid-column: 2; }
  .download-row { grid-template-columns: 1.2fr .65fr auto; }
}

@media (max-width: 760px) {
  :root { --pad: 20px; }
  .header-inner { grid-template-columns: 1fr auto auto; height: 66px; gap: 8px; }
  .nav-toggle { display: block; grid-column: 2; }
  .language-toggle { grid-column: 3; padding-left: 9px; }
  .site-nav { position: absolute; top: 66px; left: 0; right: 0; display: none; flex-direction: column; gap: 0; padding: 10px var(--pad) 20px; background: #0b0d0cf5; border-bottom: 1px solid var(--line); }
  .site-nav.open { display: flex; }
  .site-nav a { padding: 12px 0; border-bottom: 1px solid var(--line); }
  .hero { padding-top: 70px; }
  .hero h1 { font-size: clamp(3.25rem, 16vw, 5.2rem); }
  [data-language="ru"] .hero h1 { font-size: clamp(2.6rem, 13.5vw, 4.75rem); letter-spacing: -.06em; }
  .hero-stage { min-height: 390px; }
  .device-system { width: 98%; }
  .device-optivalve { width: 83%; top: 55%; }
  .catalog-intro, .downloads-head, .engineering-grid, .contact-inner { grid-template-columns: 1fr; }
  .catalog-intro { gap: 28px; }
  .product { grid-template-columns: 1fr; gap: 28px; }
  .product-number { display: none; }
  .product-copy { max-width: none; }
  .product-visual { grid-column: 1; }
  .carousel-toolbar { align-items: flex-start; flex-wrap: wrap; }
  .carousel-tabs { width: 100%; }
  .carousel-nav { margin-left: auto; }
  .system-flow-panel { aspect-ratio: auto; min-height: 470px; }
  .system-flow { grid-template-columns: 1fr; }
  .channel-bank { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .bus-bank { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .flow-chip { min-height: 70px; grid-template-columns: 1fr; grid-template-rows: auto auto auto; justify-items: center; text-align: center; }
  .flow-chip small, .flow-chip strong, .flow-chip span, .flow-chip > i { grid-column: 1; grid-row: auto; }
  .flow-chip > i { width: 100%; }
  .flow-sum { width: 62px; justify-self: center; }
  .flow-wire { width: 100%; height: 23px; }
  .flow-wire i { width: 1px; height: 100%; }
  .flow-wire i::after { right: -3px; top: auto; bottom: -1px; transform: rotate(135deg); }
  .diagram-foot { grid-template-columns: 1fr; gap: 7px; }
  .broadcurve-carousel .chart-panel { aspect-ratio: auto; min-height: 310px; }
  .optivalve-carousel .optivalve-chart-panel { aspect-ratio: auto; min-height: 325px; }
  .chart-head { display: grid; align-content: start; }
  .chart-head strong { text-align: left; }
  .racklink-diagram-panel { aspect-ratio: auto; min-height: 540px; }
  .signal-route { grid-template-columns: 1fr; gap: 8px; padding: 28px 0; }
  .route-node { min-height: 90px; }
  .route-wire { height: 34px; }
  .route-wire i { width: 1px; height: 100%; }
  .multi-device-route { grid-template-columns: 1fr; gap: 24px; }
  .multi-hub::before, .multi-hub::after { left: 50%; width: 1px; height: 24px; }
  .multi-hub::before { top: auto; right: auto; bottom: 100%; }
  .multi-hub::after { top: 100%; }
  .multi-targets::before { display: none; }
  .engineering-grid { gap: 55px; }
  .engineering-path { grid-template-columns: 1fr; gap: 0; }
  .engineering-path > span { min-height: 55px; }
  .engineering-path i { width: 1px; height: 28px; margin: 3px 0 10px 7px; }
  .downloads-head { gap: 30px; }
  .download-row { grid-template-columns: 1fr; gap: 18px; }
  .download-menu { justify-self: stretch; width: 100%; }
  .download-options { position: static; width: 100%; margin-top: 8px; }
  .verification-list > div { grid-template-columns: 1fr auto; }
  .verification-list code { grid-column: 1 / -1; grid-row: 2; }
  .contact-inner > p:not(.section-index) { margin-top: 20px; }
  .email-copy { grid-column: 1; }
  .footer-inner { flex-wrap: wrap; padding-block: 26px; }
}

@media (max-width: 460px) {
  .hero-stage { min-height: 315px; }
  .stage-readout { display: none; }
  .engineering-metrics { grid-template-columns: 1fr; }
  .engineering-metrics article { min-height: 135px; }
  .carousel-tabs button { padding-inline: 9px; font-size: .6rem; }
  .chart-legend { gap: 8px; }
  .footer-inner { display: grid; justify-content: start; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { scroll-behavior: auto !important; transition-duration: .01ms !important; animation-duration: .01ms !important; animation-iteration-count: 1 !important; }
}