:root {
  /* base surfaces */
  --ink: #0C0F13;
  --ink-2: #12161C;
  --ink-3: #191F27;
  --paper: #F4F5F3;
  --paper-2: #FFFFFF;
  --paper-3: #EAECE9;

  /* borders */
  --line-dark: #2B333C;
  --line-light: #DBDFDC;

  /* brand */
  --cyan: #00E5FF;
  --cyan-deep: #007A94;
  --violet: #7B61FF;
  --violet-deep: #5A3FDB;
  --green: #00D4A1;
  --green-deep: #00926E;

  /* text */
  --text-dark: #EEF2F4;
  --text-dark-muted: #8C9BA6;
  --text-light: #10151A;
  --text-light-muted: #5B6469;

  --font-display: 'Space Grotesk', sans-serif;
  --font-body: 'Inter', sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* contextual tokens — redefined per section */
  --fg: var(--text-dark);
  --fg-muted: var(--text-dark-muted);
  --surface: var(--ink-2);
  --surface-2: var(--ink-3);
  --border: var(--line-dark);
  --accent: var(--cyan);
  --accent-2: var(--violet);
  --accent-3: var(--green);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; }
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; animation-iteration-count: 1 !important; transition-duration: 0.01ms !important; scroll-behavior: auto !important; }
}

body {
  background: var(--ink);
  color: var(--text-dark);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  overflow-x: hidden;
}

a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.section-light {
  --fg: var(--text-light);
  --fg-muted: var(--text-light-muted);
  --surface: var(--paper-2);
  --surface-2: var(--paper-3);
  --border: var(--line-light);
  --accent: var(--cyan-deep);
  --accent-2: var(--violet-deep);
  --accent-3: var(--green-deep);
  background: var(--paper);
  color: var(--text-light);
}
.section-dark {
  background: var(--ink-2);
  color: var(--text-dark);
}

/* ─── NAV (always dark — persistent chrome) ─── */
nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  display: flex; align-items: center; justify-content: space-between;
  padding: 18px 60px;
  background: rgba(12,15,19,0.82);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--line-dark);
}
.nav-logo { font-family: var(--font-display); font-size: 22px; font-weight: 700; letter-spacing: 0.08em; color: var(--text-dark); text-decoration: none; }
.nav-logo span { color: var(--cyan); }
.nav-links { display: flex; gap: 36px; list-style: none; }
.nav-links a { font-family: var(--font-body); font-size: 13px; font-weight: 500; color: var(--text-dark-muted); text-decoration: none; letter-spacing: 0.05em; text-transform: uppercase; transition: color 0.2s; }
.nav-links a:hover { color: var(--cyan); }
.nav-cta { background: transparent; border: 1px solid var(--cyan); color: var(--cyan); font-family: var(--font-display); font-size: 13px; font-weight: 600; letter-spacing: 0.06em; padding: 9px 22px; cursor: pointer; text-decoration: none; transition: background 0.2s, color 0.2s; }
.nav-cta:hover { background: var(--cyan); color: var(--ink); }

/* ─── HERO ─── */
.hero { min-height: 100vh; display: flex; flex-direction: column; justify-content: center; padding: 140px 60px 100px; position: relative; overflow: hidden; }
.hero::before { content:''; position:absolute; top:-200px; right:-200px; width:700px; height:700px; background: radial-gradient(circle, rgba(0,229,255,0.06) 0%, transparent 70%); pointer-events:none; }
.hero::after { content:''; position:absolute; bottom:-150px; left:-100px; width:500px; height:500px; background: radial-gradient(circle, rgba(123,97,255,0.05) 0%, transparent 70%); pointer-events:none; }

.hero-eyebrow { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.2em; color: var(--cyan); text-transform: uppercase; margin-bottom: 28px; display:flex; align-items:center; gap:12px; }
.hero-eyebrow::before { content:''; display:inline-block; width:32px; height:1px; background: var(--cyan); }

.hero-h1 { font-family: var(--font-display); font-size: clamp(38px, 5.2vw, 68px); font-weight: 700; line-height: 1.12; letter-spacing: -0.01em; max-width: 920px; margin-bottom: 32px; color: var(--text-dark); }
.hero-h1 .dim { color: var(--text-dark-muted); font-weight: 400; }
.hero-h1 .accent { color: var(--cyan); }

.hero-body { font-size: 18px; color: var(--text-dark-muted); max-width: 560px; line-height: 1.7; margin-bottom: 48px; }

.hero-ctas { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 90px; }
.btn-primary { background: var(--cyan); color: var(--ink); font-family: var(--font-display); font-size: 14px; font-weight: 700; letter-spacing: 0.05em; padding: 16px 36px; border: none; cursor: pointer; text-decoration: none; display: inline-block; transition: opacity 0.2s, transform 0.2s; }
.btn-primary:hover { opacity: 0.88; transform: translateY(-1px); }
.btn-secondary { background: transparent; color: var(--fg); font-family: var(--font-display); font-size: 14px; font-weight: 500; letter-spacing: 0.05em; padding: 15px 36px; border: 1px solid var(--border); cursor: pointer; text-decoration: none; display: inline-block; transition: border-color 0.2s, color 0.2s; }
.btn-secondary:hover { border-color: var(--accent); color: var(--accent); }

.hero-compare { display: flex; gap: 0; border: 1px solid var(--line-dark); max-width: 640px; }
.hero-compare-col { flex: 1; padding: 24px 28px; }
.hero-compare-col:first-child { border-right: 1px solid var(--line-dark); }
.hero-compare-label { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.15em; text-transform: uppercase; color: var(--text-dark-muted); margin-bottom: 10px; }
.hero-compare-value { font-family: var(--font-display); font-size: 22px; font-weight: 700; }
.hero-compare-col:first-child .hero-compare-value { color: var(--text-dark); }
.hero-compare-col:last-child .hero-compare-value { color: var(--cyan); }
.hero-compare-sub { font-size: 12px; color: var(--text-dark-muted); margin-top: 6px; }

/* ─── SECTION SHARED ─── */
.section { padding: 120px 60px; position: relative; }
.section-eyebrow { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.2em; color: var(--accent); text-transform: uppercase; margin-bottom: 24px; display:flex; align-items:center; gap:12px; }
.section-eyebrow::before { content:''; display:inline-block; width:24px; height:1px; background: var(--accent); }
.section-h2 { font-family: var(--font-display); font-size: clamp(28px, 3.6vw, 48px); font-weight: 700; line-height: 1.15; letter-spacing: -0.01em; max-width: 780px; margin-bottom: 24px; color: var(--fg); }
.section-h2 .accent { color: var(--accent); }
.section-h2 .accent-v { color: var(--accent-2); }
.section-lead { font-size: 17px; color: var(--fg-muted); max-width: 620px; line-height: 1.75; }
.divider { height: 1px; background: var(--line-dark); margin: 0 60px; }
.section-light + .divider, .section-light ~ .divider { background: var(--line-light); }

/* ─── WHY / CONTEXT (2) ─── */
.why-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1px; background: var(--border); border: 1px solid var(--border); margin-top: 56px; }
.why-card { background: var(--surface); padding: 44px 40px; }
.why-card-label { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.15em; text-transform: uppercase; margin-bottom: 16px; }
.why-card.digital .why-card-label { color: var(--fg-muted); }
.why-card.physical .why-card-label { color: var(--accent); }
.why-card-body { font-size: 16px; color: var(--fg); line-height: 1.7; }

/* ─── WHAT (3) ─── */
.what-statement { padding: 100px 60px; text-align: center; }
.what-statement-eyebrow { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.2em; color: var(--text-dark-muted); text-transform: uppercase; margin-bottom: 28px; }
.what-statement-text { font-family: var(--font-display); font-size: clamp(28px, 4vw, 52px); font-weight: 700; line-height: 1.25; max-width: 920px; margin: 0 auto; letter-spacing: -0.01em; color: var(--text-dark); }
.what-statement-text .accent { color: var(--cyan); }

/* ─── LINES OF BUSINESS (4) ─── */
.lines-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; margin-top: 56px; }
.line-card { border: 1px solid var(--border); background: var(--surface); padding: 40px 32px; position: relative; overflow: hidden; transition: border-color 0.3s; }
.line-card::before { content:''; position:absolute; top:0; left:0; right:0; height:3px; }
.line-card.led::before { background: var(--accent); }
.line-card.retrofit::before { background: var(--accent-2); }
.line-card.sensors::before { background: var(--accent-3); }
.line-card:hover { border-color: var(--accent); }
.line-number { font-family: var(--font-mono); font-size: 11px; color: var(--fg-muted); letter-spacing: 0.15em; margin-bottom: 20px; }
.line-title { font-family: var(--font-display); font-size: 22px; font-weight: 700; margin-bottom: 14px; line-height: 1.25; }
.line-card.led .line-title { color: var(--accent); }
.line-card.retrofit .line-title { color: var(--accent-2); }
.line-card.sensors .line-title { color: var(--accent-3); }
.line-desc { font-size: 14px; color: var(--fg-muted); line-height: 1.7; margin-bottom: 24px; }
.line-includes { list-style: none; }
.line-includes li { font-size: 13px; color: var(--fg); padding: 7px 0; border-top: 1px solid var(--border); display: flex; align-items: center; gap: 10px; }
.line-includes li:first-child { border-top: none; }
.line-includes li::before { content: '✓'; font-family: var(--font-mono); font-size: 12px; flex-shrink: 0; }
.line-card.led li::before { color: var(--accent); }
.line-card.retrofit li::before { color: var(--accent-2); }
.line-card.sensors li::before { color: var(--accent-3); }

/* ─── WHAT YOU CAN UNDERSTAND (5) ─── */
.understand-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1px; background: var(--border); border: 1px solid var(--border); margin-top: 56px; }
.understand-card { background: var(--surface); padding: 36px 32px; transition: background 0.3s; }
.understand-card:hover { background: var(--surface-2); }
.understand-card-label { font-family: var(--font-mono); font-size: 10px; color: var(--accent); letter-spacing: 0.15em; text-transform: uppercase; margin-bottom: 14px; }
.understand-card-q { font-family: var(--font-display); font-size: 18px; font-weight: 600; color: var(--fg); line-height: 1.4; }

/* ─── HOW IT WORKS (6) ─── */
.how-flow { display: flex; align-items: center; justify-content: space-between; margin-top: 64px; flex-wrap: wrap; gap: 12px; }
.how-step { flex: 1; min-width: 150px; text-align: center; padding: 32px 16px; border: 1px solid var(--border); background: var(--surface); }
.how-step-num { font-family: var(--font-mono); font-size: 11px; color: var(--accent); letter-spacing: 0.1em; margin-bottom: 14px; }
.how-step-label { font-family: var(--font-display); font-size: 15px; font-weight: 600; color: var(--fg); }
.how-step-tag { font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.08em; color: var(--fg-muted); margin-top: 10px; }
.how-arrow { font-family: var(--font-mono); font-size: 18px; color: var(--border); flex-shrink: 0; }
@media (max-width: 900px) { .how-arrow { transform: rotate(90deg); } }

/* ─── WHY DIFFERENT (7) ─── */
.diff-flow { display: flex; align-items: center; justify-content: center; gap: 20px; margin-top: 56px; flex-wrap: wrap; }
.diff-node { font-family: var(--font-display); font-size: 16px; font-weight: 600; color: var(--fg); border: 1px solid var(--border); background: var(--surface); padding: 16px 28px; }
.diff-node.result { color: var(--accent); border-color: var(--accent); }
.diff-arrow { color: var(--fg-muted); font-family: var(--font-mono); }

/* ─── USE CASES (8) ─── */
.cases-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px; background: var(--border); border: 1px solid var(--border); margin-top: 56px; }
.case-tile { background: var(--surface); padding: 32px 20px; text-align: center; font-family: var(--font-display); font-size: 15px; font-weight: 600; color: var(--fg); transition: color 0.3s, background 0.3s; }
.case-tile:hover { color: var(--accent); background: var(--surface-2); }

/* ─── VISION (9) ─── */
.vision-callout { background: var(--ink-3); border: 1px solid var(--cyan-deep); margin: 0 60px 120px; padding: 72px 80px; position: relative; overflow: hidden; }
.vision-callout::before { content:''; position:absolute; top:-100px; right:-100px; width:400px; height:400px; background: radial-gradient(circle, rgba(0,229,255,0.08) 0%, transparent 70%); pointer-events:none; }
.vision-label { font-family: var(--font-mono); font-size: 11px; color: var(--cyan); letter-spacing: 0.2em; text-transform: uppercase; margin-bottom: 28px; }
.vision-text { font-family: var(--font-display); font-size: clamp(22px, 2.6vw, 34px); font-weight: 700; line-height: 1.35; letter-spacing: -0.01em; max-width: 780px; color: var(--text-dark); }
.vision-text .grey { color: var(--text-dark-muted); font-weight: 400; }
.vision-text .accent { color: var(--cyan); }

/* ─── CTA FINAL ─── */
.cta-final { padding: 140px 60px; text-align: center; position: relative; overflow: hidden; }
.cta-final::before { content:''; position:absolute; top:50%; left:50%; transform:translate(-50%,-50%); width:800px; height:400px; background: radial-gradient(ellipse, rgba(0,229,255,0.05) 0%, transparent 70%); pointer-events:none; }
.cta-final-eyebrow { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.2em; color: var(--cyan); text-transform: uppercase; margin-bottom: 28px; }
.cta-final-h2 { font-family: var(--font-display); font-size: clamp(32px, 4.4vw, 52px); font-weight: 700; line-height: 1.2; letter-spacing: -0.01em; margin-bottom: 20px; color: var(--text-dark); }
.cta-final-q { font-size: 19px; color: var(--text-dark); max-width: 560px; margin: 0 auto 16px; font-weight: 500; }
.cta-final-body { font-size: 16px; color: var(--text-dark-muted); max-width: 480px; margin: 0 auto 44px; line-height: 1.7; }
.cta-final-actions { display: flex; justify-content: center; }

/* ─── FOOTER ─── */
footer { background: var(--ink-2); border-top: 1px solid var(--line-dark); padding: 48px 60px; display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 24px; }
.footer-logo { font-family: var(--font-display); font-size: 20px; font-weight: 700; letter-spacing: 0.08em; color: var(--text-dark); }
.footer-logo span { color: var(--cyan); }
.footer-tagline { font-family: var(--font-mono); font-size: 11px; color: var(--text-dark-muted); letter-spacing: 0.05em; margin-top: 6px; }
.footer-copy { font-family: var(--font-mono); font-size: 11px; color: var(--text-dark-muted); letter-spacing: 0.05em; }

/* ─── RESPONSIVE ─── */
@media (max-width: 900px) {
  nav { padding: 16px 24px; }
  .nav-links { display: none; }
  .hero { padding: 100px 24px 60px; }
  .section, .what-statement, .cta-final { padding: 72px 24px; }
  .why-grid { grid-template-columns: 1fr; }
  .lines-grid { grid-template-columns: 1fr; }
  .understand-grid { grid-template-columns: 1fr; }
  .cases-grid { grid-template-columns: repeat(2, 1fr); }
  .vision-callout { margin: 0 24px 72px; padding: 44px 28px; }
  .divider { margin: 0 24px; }
  footer { flex-direction: column; align-items: flex-start; padding: 36px 24px; }
  .hero-compare { flex-direction: column; }
  .hero-compare-col:first-child { border-right: none; border-bottom: 1px solid var(--line-dark); }
}