:root {
  --bg: #0B0F19;
  --bg-raised: #111727;
  --bg-card: #141B2D;
  --border: #1F2937;
  --border-strong: #2B3750;
  --text: #F8FAFC;
  --text-dim: #A3AEC2;
  --text-faint: #6B7690;
  --emerald: #34D399;
  --tangerine: #FB923C;
  --red: #F87171;
  --radius: 12px;
  --mono: ui-monospace, "SF Mono", SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, "Helvetica Neue", Arial, sans-serif;
  --on-accent: #04130D;
  color-scheme: dark;
}

/* Light palette: follows the OS unless the visitor picked a theme (data-theme set by theme.js). */
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #F8FAFC;
    --bg-raised: #FFFFFF;
    --bg-card: #FFFFFF;
    --border: #E2E8F0;
    --border-strong: #CBD5E1;
    --text: #0B0F19;
    --text-dim: #334155;
    --text-faint: #64748B;
    --emerald: #047857;
    --tangerine: #C2410C;
    --red: #DC2626;
    --on-accent: #FFFFFF;
    color-scheme: light;
  }
}
:root[data-theme="light"] {
  --bg: #F8FAFC;
  --bg-raised: #FFFFFF;
  --bg-card: #FFFFFF;
  --border: #E2E8F0;
  --border-strong: #CBD5E1;
  --text: #0B0F19;
  --text-dim: #334155;
  --text-faint: #64748B;
  --emerald: #047857;
  --tangerine: #C2410C;
  --red: #DC2626;
  --on-accent: #FFFFFF;
  color-scheme: light;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text-dim);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3 { color: var(--text); line-height: 1.15; margin: 0 0 .6em; letter-spacing: -0.02em; }
h1 { font-size: clamp(2.2rem, 5.5vw, 4rem); font-weight: 750; }
h2 { font-size: clamp(1.7rem, 3.5vw, 2.5rem); font-weight: 700; }
h3 { font-size: 1.2rem; font-weight: 650; }
p { margin: 0 0 1em; }
strong { color: var(--text); font-weight: 600; }
a { color: var(--tangerine); }
:focus-visible { outline: 2px solid var(--tangerine); outline-offset: 3px; border-radius: 4px; }

.container { width: min(1160px, 100% - 32px); margin-inline: auto; }
.accent {
  background: linear-gradient(90deg, var(--emerald), var(--tangerine));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.muted { color: var(--text-faint); }

.skip-link { position: absolute; left: -9999px; top: 8px; z-index: 100; background: var(--emerald); color: var(--bg); padding: 8px 14px; border-radius: 6px; font-weight: 600; }
.skip-link:focus { left: 16px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; gap: 16px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--text); font-weight: 700; letter-spacing: -0.01em; }
.brand-name { text-transform: uppercase; letter-spacing: .12em; font-size: 15px; }
.brand-a { color: var(--tangerine); }
.brand-b { color: var(--emerald); }
.brand-mark { display: block; width: 32px; height: 32px; border-radius: 7px; }
.brand-mark.small { display: inline-block; width: 22px; height: 22px; border-radius: 5px; vertical-align: middle; margin-right: 6px; }
.nav-links { display: flex; align-items: center; gap: 28px; list-style: none; margin: 0; padding: 0; }
.nav-links a { color: var(--text-dim); text-decoration: none; font-size: 15px; }
.nav-links a:hover { color: var(--text); }
.site-header nav { display: flex; align-items: center; gap: 16px; }
.theme-toggle {
  display: inline-flex; align-items: center; justify-content: center; width: 36px; height: 36px; padding: 0;
  border-radius: 8px; border: 1px solid var(--border-strong); background: transparent; color: var(--text-dim); cursor: pointer;
}
.theme-toggle:hover { color: var(--text); border-color: var(--tangerine); }
.theme-toggle[hidden] { display: none; }
.theme-toggle svg { width: 18px; height: 18px; }
.theme-toggle .icon-moon, [data-theme-active="light"] .theme-toggle .icon-sun { display: none; }
[data-theme-active="light"] .theme-toggle .icon-moon { display: block; }
.nav-links .nav-cta { color: var(--emerald); border: 1px solid color-mix(in srgb, var(--emerald) 40%, transparent); padding: 7px 14px; border-radius: 8px; }
.nav-links .nav-cta:hover { background: color-mix(in srgb, var(--emerald) 10%, transparent); color: var(--emerald); }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center; text-align: center;
  padding: 14px 22px; border-radius: 10px; font: 600 16px/1.3 var(--sans);
  text-decoration: none; cursor: pointer; border: 1px solid transparent;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease, border-color .15s ease;
}
.btn-primary { background: var(--emerald); color: var(--on-accent); box-shadow: 0 0 0 0 color-mix(in srgb, var(--emerald) 0%, transparent); }
.btn-primary:hover { transform: translateY(-1px); box-shadow: 0 8px 30px -8px color-mix(in srgb, var(--emerald) 60%, transparent); }
.btn-ghost { color: var(--text); border-color: var(--border-strong); background: color-mix(in srgb, var(--text) 2%, transparent); }
.btn-ghost:hover { border-color: var(--tangerine); color: var(--tangerine); }
.btn-block { width: 100%; }
.btn[disabled] { opacity: .6; cursor: progress; transform: none; }

/* Hero */
.hero { position: relative; overflow: hidden; padding: clamp(72px, 12vw, 140px) 0 clamp(64px, 9vw, 110px); border-bottom: 1px solid var(--border); }
.grid-bg {
  position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(color-mix(in srgb, var(--tangerine) 6%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--tangerine) 6%, transparent) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 70% 60% at 50% 30%, #000 30%, transparent 75%);
}
.hero::after {
  content: ""; position: absolute; width: 640px; height: 640px; right: -200px; top: -240px; pointer-events: none;
  background: radial-gradient(circle, color-mix(in srgb, var(--emerald) 16%, transparent), transparent 65%);
}
.hero-inner { position: relative; z-index: 1; max-width: 920px; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 10px; font-family: var(--mono); font-size: 13px;
  color: var(--emerald); border: 1px solid color-mix(in srgb, var(--emerald) 30%, transparent); background: color-mix(in srgb, var(--emerald) 6%, transparent);
  padding: 6px 12px; border-radius: 999px; margin-bottom: 28px;
}
.pulse { width: 8px; height: 8px; border-radius: 50%; background: var(--emerald); box-shadow: 0 0 0 0 color-mix(in srgb, var(--emerald) 70%, transparent); animation: pulse 2s infinite; }
@keyframes pulse { 70% { box-shadow: 0 0 0 10px color-mix(in srgb, var(--emerald) 0%, transparent); } 100% { box-shadow: 0 0 0 0 color-mix(in srgb, var(--emerald) 0%, transparent); } }
.lede { font-size: clamp(1.05rem, 1.8vw, 1.25rem); max-width: 780px; margin-bottom: 36px; }
.cta-row { display: flex; flex-wrap: wrap; gap: 14px; }
.trust-row { display: flex; flex-wrap: wrap; gap: 8px 24px; list-style: none; padding: 0; margin: 48px 0 0; font-family: var(--mono); font-size: 13px; color: var(--text-faint); text-transform: uppercase; letter-spacing: .06em; }
.trust-row li::before { content: "▸ "; color: var(--tangerine); }

/* Sections */
.section { padding: clamp(64px, 9vw, 110px) 0; }
.section-head { max-width: 760px; margin-bottom: 48px; }
.section-tag { font-family: var(--mono); font-size: 13px; color: var(--tangerine); letter-spacing: .04em; margin-bottom: 14px; }

.layer-divider {
  position: relative; border: 0; height: 1px; margin: 0;
  background: linear-gradient(90deg, transparent, var(--border-strong) 20%, var(--border-strong) 80%, transparent);
  overflow: visible;
}
.layer-divider::after {
  content: attr(data-label); position: absolute; left: 50%; top: 50%; transform: translate(-50%, -50%);
  background: var(--bg); padding: 0 14px; font-family: var(--mono); font-size: 11px; letter-spacing: .14em;
  color: var(--text-faint); white-space: nowrap;
}

/* Metric */
.metric { display: grid; grid-template-columns: minmax(0, 5fr) minmax(0, 7fr); gap: clamp(32px, 6vw, 80px); align-items: center; }
.metric-figure {
  display: flex; flex-direction: column; align-items: center; text-align: center;
  background: var(--bg-raised); border: 1px solid var(--border); border-radius: var(--radius); padding: 40px 24px;
}
.ratio { font-family: var(--mono); font-size: clamp(4rem, 10vw, 6.5rem); font-weight: 700; line-height: 1; color: var(--text); }
.ratio .colon { color: var(--emerald); padding: 0 .08em; }
.ratio-label { font-family: var(--mono); font-size: 12px; text-transform: uppercase; letter-spacing: .16em; color: var(--text-faint); margin: 10px 0 28px; }
.devices { display: flex; flex-wrap: wrap; gap: 8px; justify-content: center; }
.chip { font-family: var(--mono); font-size: 12px; padding: 6px 10px; border-radius: 6px; border: 1px solid var(--border-strong); color: var(--text-dim); background: var(--bg-card); }
.converge { width: 1px; height: 36px; margin: 10px 0; background: linear-gradient(var(--border-strong), var(--emerald)); }
.chip-identity { border-color: color-mix(in srgb, var(--emerald) 50%, transparent); color: var(--emerald); background: color-mix(in srgb, var(--emerald) 8%, transparent); }

/* Comparison */
.compare { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.compare-col { border-radius: var(--radius); padding: clamp(24px, 3.5vw, 40px); border: 1px solid var(--border); background: var(--bg-raised); }
.col-label { font-family: var(--mono); font-size: 12px; text-transform: uppercase; letter-spacing: .1em; color: var(--text-faint); display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.legacy h3 { color: var(--text-dim); }
.modern {
  position: relative; background: linear-gradient(180deg, color-mix(in srgb, var(--emerald) 7%, transparent), color-mix(in srgb, var(--tangerine) 2%, transparent) 60%), var(--bg-card);
  border-color: color-mix(in srgb, var(--emerald) 45%, transparent); box-shadow: 0 0 0 1px color-mix(in srgb, var(--emerald) 8%, transparent), 0 24px 60px -30px color-mix(in srgb, var(--emerald) 45%, transparent);
}
.modern .col-label { color: var(--emerald); }
.badge { background: var(--emerald); color: var(--on-accent); padding: 2px 8px; border-radius: 4px; font-size: 11px; font-weight: 700; }
.spec-list { list-style: none; padding: 0; margin: 24px 0 0; display: grid; gap: 18px; }
.spec-list li { position: relative; padding: 0 0 18px 30px; border-bottom: 1px dashed var(--border); }
.spec-list li:last-child { border-bottom: 0; padding-bottom: 0; }
.spec-list li::before { position: absolute; left: 0; top: 1px; font-family: var(--mono); font-weight: 700; }
.legacy .spec-list li::before { content: "✕"; color: var(--red); }
.modern .spec-list li::before { content: "✓"; color: var(--emerald); }

/* OS grid */
.os-grid { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 20px; }
.os-card {
  background: var(--bg-raised); border: 1px solid var(--border); border-radius: var(--radius); padding: 28px 24px;
  transition: border-color .2s ease, transform .2s ease;
}
.os-card:hover { border-color: color-mix(in srgb, var(--tangerine) 50%, transparent); transform: translateY(-2px); }
.os-id { display: inline-block; font-family: var(--mono); font-size: 11px; letter-spacing: .12em; color: var(--tangerine); border: 1px solid color-mix(in srgb, var(--tangerine) 35%, transparent); padding: 3px 8px; border-radius: 4px; margin-bottom: 20px; }
.os-card p:last-child { margin: 0; font-size: 15.5px; }

/* Audit */
.audit { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: clamp(32px, 6vw, 72px); align-items: start; }
.check-list { list-style: none; padding: 0; margin: 28px 0 0; display: grid; gap: 10px; }
.check-list li { font-family: var(--mono); font-size: 14px; color: var(--text); }
.check-list li::before { content: "[✓] "; color: var(--emerald); }
.audit-form { background: var(--bg-card); border: 1px solid var(--border-strong); border-radius: var(--radius); padding: clamp(24px, 3.5vw, 36px); }
.field { margin-bottom: 18px; }
.field label { display: block; font-size: 14px; font-weight: 600; color: var(--text); margin-bottom: 8px; }
.field input, .field select {
  width: 100%; padding: 12px 14px; border-radius: 8px; font: 16px/1.4 var(--sans);
  color: var(--text); background: var(--bg); border: 1px solid var(--border-strong);
  transition: border-color .15s ease, box-shadow .15s ease;
}
.field select { appearance: none; background-image: linear-gradient(45deg, transparent 50%, var(--text-faint) 50%), linear-gradient(135deg, var(--text-faint) 50%, transparent 50%); background-position: calc(100% - 20px) 55%, calc(100% - 15px) 55%; background-size: 5px 5px; background-repeat: no-repeat; padding-right: 40px; }
.field input:focus, .field select:focus { outline: none; border-color: var(--emerald); box-shadow: 0 0 0 3px color-mix(in srgb, var(--emerald) 20%, transparent); }
.field [aria-invalid="true"] { border-color: var(--red); }
.field-error { color: var(--red); font-size: 13px; margin: 6px 0 0; min-height: 0; }
.field-error:empty { display: none; }
.hp { position: absolute; left: -10000px; width: 1px; height: 1px; overflow: hidden; }
.form-note { font-size: 13px; color: var(--text-faint); margin: 14px 0 0; }
.form-status { margin: 14px 0 0; font-family: var(--mono); font-size: 14px; }
.form-status:empty { display: none; }
.form-status.ok { color: var(--emerald); }
.form-status.err { color: var(--red); }

/* Footer */
.site-footer { border-top: 1px solid var(--border); padding: 32px 0; font-size: 14px; }
.privacy-notice { max-width: 860px; padding-bottom: 24px; margin-bottom: 24px; border-bottom: 1px solid var(--border); }
.privacy-notice h2 { font-family: var(--mono); font-size: 12px; font-weight: 600; text-transform: uppercase; letter-spacing: .12em; color: var(--text-faint); margin-bottom: 10px; }
.privacy-notice p { font-size: 13px; line-height: 1.7; color: var(--text-faint); margin: 0; }
.footer-inner { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 12px; }
.footer-inner p { margin: 0; }

/* Responsive */
@media (max-width: 960px) {
  .os-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .metric, .audit, .compare { grid-template-columns: 1fr; }
}
@media (max-width: 720px) {
  .nav-links li:not(:last-child) { display: none; }
  .cta-row .btn { width: 100%; }
  .os-grid { grid-template-columns: 1fr; }
  .layer-divider::after { font-size: 10px; letter-spacing: .1em; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}