:root {
  --bg: #202020;
  --text: #c7d0ed;
  --heading: #cbd5f2;
  --accent: #79a9e9;
  --nav: #c8cfe4;
  --container: 1180px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  background: var(--bg);
  color: var(--text);
  font-family: "Montserrat", Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}
img { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
.container { width: min(calc(100% - 48px), var(--container)); margin: 0 auto; }
.sr-only { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); white-space: nowrap; border: 0; }

.site-header {
  position: absolute;
  inset: 0 0 auto;
  z-index: 10;
  padding: 28px 0;
}
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 48px; }
.brand { width: clamp(220px, 27vw, 340px); flex: 0 0 auto; }
.brand img { width: 100%; }
.nav { display: flex; align-items: center; gap: clamp(28px, 4vw, 58px); }
.nav a { color: var(--nav); font-size: clamp(16px, 1.55vw, 22px); font-weight: 400; transition: color .2s ease, transform .2s ease; }
.nav a:hover, .nav a:focus-visible, .nav a.active { color: #eef3ff; transform: translateY(-1px); }
.menu-toggle { display: none; width: 44px; height: 44px; padding: 9px; border: 1px solid rgba(199,208,237,.3); border-radius: 10px; background: rgba(32,32,32,.85); }
.menu-toggle span:not(.sr-only) { display: block; height: 2px; margin: 5px 0; background: var(--heading); transition: .2s ease; }

.hero {
  position: relative;
  min-height: 700px;
  overflow: hidden;
  padding-top: 132px;
}
.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at 50% 45%, rgba(46,60,125,.14), transparent 38%);
  pointer-events: none;
}
.circuit { position: absolute; left: 50%; width: max(1200px, 100vw); max-width: none; transform: translateX(-50%); object-fit: cover; pointer-events: none; user-select: none; }
.circuit-top { top: 256px; }
.circuit-bottom { bottom: 10%; transform: scaleX(-1); left: 0%;}
.hero-content { position: relative; z-index: 2; display: grid; place-items: center; min-height: 1220px; text-align: center; }
h1 { margin: 0; color: var(--heading); font-size: clamp(28px, 6vw, 38px); line-height: 1.16; font-weight: 400; letter-spacing: .03em; text-shadow: 0 3px 24px rgba(0,0,0,.4); }

.about { position: relative; min-height: 900px; overflow: hidden; padding: 20px 0 48px; }
.about-inner { position: relative; z-index: 2; }
.section-mark { width: min(440px, 42vw); margin: 92px auto 16px; }
.content-card { width: min(100%, 570px); margin: 92px auto 0; }
.content-card h2 { margin: 0 0 22px; color: var(--heading); font-size: 20px; line-height: 1.2; font-weight: 700; }
.content-card h3 { margin: 30px 0 12px; color: var(--heading); font-size: 21px; line-height: 1.25; font-weight: 700; }
.content-card p { margin: 0 0 17px; font-size: 18px; line-height: 1.27; letter-spacing: .01em; }
.tagline { margin: 72px 0 0; text-align: center; color: var(--heading); font-size: clamp(20px, 2vw, 27px); }
.side-art { position: absolute; bottom: 160px; width: min(28vw, 335px); pointer-events: none; user-select: none; opacity: .2;}
.side-art-left { left: 0; }
.side-art-right { right: 0; }
.placeholder-section { min-height: 1px; }

@media (max-width: 900px) {
  .site-header { position: fixed; padding: 12px 0; background: rgba(32,32,32,.92); backdrop-filter: blur(10px); box-shadow: 0 1px 0 rgba(199,208,237,.08); }
  .brand { width: 205px; }
  .menu-toggle { display: block; position: relative; z-index: 12; }
  .nav {
    position: fixed;
    inset: 0 0 auto;
    display: grid;
    gap: 0;
    padding: 92px 24px 24px;
    background: rgba(25,25,27,.98);
    transform: translateY(-110%);
    transition: transform .25s ease;
    box-shadow: 0 12px 30px rgba(0,0,0,.35);
  }
  .nav.open { transform: translateY(0); }
  .nav a { padding: 16px 0; border-bottom: 1px solid rgba(199,208,237,.1); font-size: 18px; }
  .menu-toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
  .menu-toggle[aria-expanded="true"] span:nth-child(2) { opacity: 0; }
  .menu-toggle[aria-expanded="true"] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }
  .hero { min-height: 660px; padding-top: 82px; }
  .hero-content { min-height: 840px; }
  .circuit { width: 1050px; opacity: .85; }
  .circuit-top { top: 112px; }
  .content-card { width: min(100%, 630px); }
  .side-art { opacity: .2; width: 310px; bottom: 80px; }
  .side-art-left { left: -125px; }
  .side-art-right { right: -125px; }
  .about { padding-top: 0; }
}

@media (max-width: 600px) {
  .container { width: min(calc(100% - 30px), var(--container)); }
  .brand { width: 175px; }
  .hero { min-height: 520px; }
  .hero-content { min-height: 600px; padding-inline: 6px; }
  h1 { font-size: clamp(18px, 6vw, 38px); line-height: 1.14; }
  .circuit { width: 920px; opacity: .72; }
  .circuit-top { top: 100px; }
  .circuit-bottom { bottom: 10%; }
  .section-mark { margin-top:32px; width: min(360px, 94vw);}
  .content-card h2 { font-size: 18px; }
  .content-card h2 br { display: none; }
  .content-card h3 { font-size: 20px; margin-top: 28px; }
  .content-card p { font-size: 16px; line-height: 1.45; }
  .tagline { margin-top: 48px; font-size: 19px; line-height: 1.35; }
  .side-art { width: 260px; opacity: .12; bottom: 100px; }
}

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