:root {
  --ink: #050a1a;
  --navy: #0a1130;
  --panel: #101a3d;
  --panel-2: #16224b;
  --cyan: #12b5f0;
  --cyan-dim: #0d8fc0;
  --text: #e9eefb;
  --muted: #93a1c4;
  --line: rgba(255, 255, 255, 0.09);
  --line-strong: rgba(255, 255, 255, 0.18);
  --radius: 6px;
  --maxw: 1200px;
  --gutter: 24px;
  --font: "Inter", "Helvetica Neue", Arial, "Noto Sans SC", sans-serif;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--ink);
  color: var(--text);
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

img { display: block; max-width: 100%; }

a { color: inherit; text-decoration: none; }

h1, h2, h3, h4 { margin: 0; font-weight: 650; letter-spacing: -0.015em; line-height: 1.2; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 var(--gutter); }

.eyebrow {
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
  margin-bottom: 14px;
}

.section { padding: 96px 0; }
.section--tight { padding: 72px 0; }

.section-head { max-width: 720px; margin-bottom: 44px; }
.section-head h2 { font-size: clamp(26px, 3.4vw, 40px); margin-bottom: 14px; }
.section-head p { margin: 0; color: var(--muted); font-size: 17px; }

/* ---------- nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(5, 10, 26, 0.82);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.nav-inner {
  display: flex;
  align-items: center;
  gap: 28px;
  height: 68px;
}

.brand { display: flex; align-items: center; gap: 10px; flex: 0 0 auto; }
.brand img { height: 30px; width: auto; }

.nav-links { display: flex; gap: 26px; margin-left: auto; }
.nav-links a { font-size: 15px; color: var(--muted); transition: color 0.18s; }
.nav-links a:hover { color: var(--text); }

.nav-cta {
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  padding: 9px 16px;
  font-size: 14px;
  transition: border-color 0.18s, background 0.18s;
}
.nav-cta:hover { border-color: var(--cyan); background: rgba(18, 181, 240, 0.1); }

.nav-toggle {
  display: none;
  margin-left: auto;
  background: none;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  color: var(--text);
  padding: 7px 11px;
  font-size: 15px;
}

/* ---------- hero ---------- */
.hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(1100px 520px at 78% 8%, rgba(18, 181, 240, 0.18), transparent 62%),
    linear-gradient(168deg, #0b1338 0%, #131c4d 46%, #1a1330 100%);
}

.hero::after {
  content: "";
  position: absolute;
  inset: auto 0 0 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--line-strong), transparent);
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  gap: 40px;
  align-items: center;
  padding: 84px 0 66px;
}

.hero h1 {
  font-size: clamp(32px, 5vw, 58px);
  line-height: 1.1;
  margin-bottom: 18px;
}

.hero-sub {
  font-size: clamp(16px, 1.6vw, 20px);
  color: #c3cee9;
  margin: 0 0 8px;
  max-width: 30ch;
}

.hero-note { color: var(--muted); font-size: 15px; margin: 0 0 30px; max-width: 46ch; }

.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  border-radius: var(--radius);
  padding: 13px 22px;
  font-size: 15px;
  font-weight: 550;
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform 0.16s, background 0.18s, border-color 0.18s;
}
.btn:active { transform: translateY(1px); }

.btn--primary { background: var(--cyan); color: #04101c; }
.btn--primary:hover { background: #35c4f7; }

.btn--ghost { border-color: var(--line-strong); color: var(--text); }
.btn--ghost:hover { border-color: var(--cyan); }

.hero-visual { position: relative; }

.hero-img {
  width: 100%;
  height: auto;
  margin-bottom: 4px;
}

.hero-cap { margin: 0; font-size: 13px; color: var(--muted); text-align: right; }

/* ---------- feature strip ---------- */
.features {
  display: grid;
  grid-template-columns: repeat(6, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.feature {
  background: var(--navy);
  padding: 26px 14px;
  text-align: center;
}

.feature svg { width: 26px; height: 26px; margin: 0 auto 12px; display: block; stroke: var(--cyan); }
.feature span { font-size: 14px; color: #cdd7ee; }

/* ---------- use cases ---------- */
.cases { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 18px; }

.case {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 26px 22px 28px;
  transition: border-color 0.2s, background 0.2s;
}
.case:hover { border-color: var(--line-strong); background: var(--panel-2); }

.case svg { width: 28px; height: 28px; stroke: var(--cyan); margin-bottom: 16px; }
.case h3 { font-size: 18px; margin-bottom: 8px; }
.case p { margin: 0; font-size: 14px; color: var(--muted); }

/* ---------- configurator ---------- */
.config {
  background: linear-gradient(180deg, var(--navy), #0b1436);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 34px;
}

.step-label {
  display: block;
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 12px;
  letter-spacing: 0.02em;
}

.config-steps {  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 22px 26px;
}

.ctrl--select select {
  width: 100%;
  background: var(--panel-2);
  color: var(--text);
  border: 1px solid var(--line-strong);
  border-radius: var(--radius);
  padding: 11px 12px;
  font: inherit;
  font-size: 15px;
  color-scheme: dark;
}
.ctrl--select select:focus-visible { outline: 2px solid var(--cyan); outline-offset: 1px; }

.ctrl--range output { float: right; color: var(--text); font-variant-numeric: tabular-nums; }

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  margin: 14px 0 0;
  background: var(--line-strong);
  border-radius: 2px;
  cursor: pointer;
}
input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--cyan);
  border: 3px solid var(--navy);
}
input[type="range"]::-moz-range-thumb {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--cyan);
  border: 3px solid var(--navy);
}
input[type="range"]:focus-visible { outline: 2px solid var(--cyan); outline-offset: 4px; }

.config-note {
  margin: 24px 0 0;
  font-size: 13px;
  color: var(--muted);
  max-width: 74ch;
}

.config-result { margin-top: 30px; border-top: 1px solid var(--line); padding-top: 26px; }
.config-result h3 { font-size: 16px; margin-bottom: 6px; }
.config-result > p { margin: 0 0 18px; font-size: 14px; color: var(--muted); }

/* ---------- product cards ---------- */
.cards { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 18px; }
.cards--few { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.card {
  display: flex;
  flex-direction: column;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  transition: border-color 0.2s, transform 0.2s;
}
.card:hover { border-color: var(--line-strong); transform: translateY(-2px); }

.card-media {
  aspect-ratio: 1 / 1;
  background: #171e23;
  display: grid;
  place-items: center;
  padding: 10px;
}
.card-media img { width: 100%; height: 100%; object-fit: contain; }

.card-body { padding: 18px 18px 20px; display: flex; flex-direction: column; gap: 8px; flex: 1; }
.card-series { font-size: 12px; letter-spacing: 0.1em; text-transform: uppercase; color: var(--muted); }
.card-body h3 { font-size: 16px; }
.card-specs { margin: 0; padding: 0; list-style: none; font-size: 13px; color: var(--muted); display: grid; gap: 3px; }
.card-price { margin-top: auto; padding-top: 10px; font-size: 14px; color: #cdd7ee; }
.card-price b { color: var(--text); font-weight: 600; }

/* ---------- contact ---------- */
.contact { background: var(--navy); border-top: 1px solid var(--line); }

.contact-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
  gap: 48px;
  align-items: start;
}

.contact-list { display: grid; gap: 2px; margin: 0; }

.contact-row {
  display: grid;
  grid-template-columns: 116px minmax(0, 1fr);
  gap: 16px;
  align-items: baseline;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}
.contact-row dt { font-size: 13px; color: var(--muted); }
.contact-row dd { margin: 0; font-size: 17px; }
.contact-row dd a:hover { color: var(--cyan); }

.qr {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 24px;
  text-align: center;
}
.qr img { width: 200px; height: 200px; margin: 0 auto 14px; background: #fff; border-radius: 4px; padding: 8px; }
.qr p { margin: 0; font-size: 14px; color: var(--muted); }
.qr strong { display: block; color: var(--text); font-size: 15px; margin-bottom: 4px; }

/* ---------- footer ---------- */
.footer { padding: 34px 0 44px; border-top: 1px solid var(--line); }
.footer-inner { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; justify-content: space-between; }
.footer p { margin: 0; font-size: 13px; color: var(--muted); }
.footer nav { display: flex; gap: 20px; font-size: 13px; }
.footer nav a { color: var(--muted); }
.footer nav a:hover { color: var(--text); }

/* ---------- reveal (progressive enhancement: visible without JS) ---------- */
.reveal.pre { opacity: 0; transform: translateY(14px); }
.reveal.pre.in { opacity: 1; transform: none; transition: opacity 0.5s ease, transform 0.5s ease; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal.pre { opacity: 1; transform: none; }
  .card:hover { transform: none; }
}

/* ---------- responsive ---------- */
@media (max-width: 1040px) {
  .hero-grid { grid-template-columns: 1fr; padding: 56px 0 44px; }
  .hero-visual { order: -1; }
  .features { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .cases { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .cards { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .cards--few { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .contact-grid { grid-template-columns: 1fr; gap: 32px; }
}

@media (max-width: 720px) {
  .section { padding: 64px 0; }
  .nav-links { display: none; }
  .nav-links.open {
    display: flex;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    flex-direction: column;
    gap: 0;
    background: var(--navy);
    border-bottom: 1px solid var(--line);
    padding: 8px var(--gutter) 16px;
  }
  .nav-links.open a { padding: 11px 0; border-bottom: 1px solid var(--line); }
  .nav-cta { display: none; }
  .nav-toggle { display: block; }
  .features { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .cases { grid-template-columns: 1fr; }
  .cards { grid-template-columns: 1fr; }
  .cards--few { grid-template-columns: 1fr; }
  .config { padding: 22px 18px; }
  .contact-row { grid-template-columns: 1fr; gap: 4px; }
}