:root {
  color-scheme: light;
  --ink: #131417;
  --muted: #666a72;
  --paper: #f7f8fa;
  --line: #d9dce2;
  --graphite: #111316;
  --amber: #ffb10a;
  --cyan: #00b7cb;
  --red: #d83a4e;
  --green: #1c9a5f;
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "SF Pro Text", "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); }
a { color: inherit; }
img { display: block; max-width: 100%; }

.site-header {
  height: 70px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 0 clamp(20px, 5vw, 74px);
  background: rgba(247, 248, 250, .96);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 20;
}
.brand { display: inline-flex; align-items: center; gap: 10px; text-decoration: none; font-weight: 760; }
.brand img { width: 36px; height: 36px; border-radius: 8px; }
nav { display: flex; align-items: center; gap: clamp(14px, 3vw, 32px); }
nav a { color: #40434a; text-decoration: none; font-size: .93rem; }
nav a:hover, nav a[aria-current="page"] { color: var(--ink); text-decoration: underline; text-underline-offset: 5px; }

.hero {
  min-height: calc(100vh - 130px);
  max-height: 880px;
  position: relative;
  display: flex;
  align-items: center;
  background: var(--graphite) url('/flipperledger/assets/screens/ipad-atlas.png') center 28% / cover no-repeat;
  overflow: hidden;
}
.hero-shade { position: absolute; inset: 0; background: rgba(10, 11, 13, .72); }
.hero-content { position: relative; width: min(920px, 90vw); margin: 0 auto; color: white; }
.hero-icon { width: 92px; height: 92px; border-radius: 20px; box-shadow: 0 16px 50px rgba(0, 0, 0, .35); }
.eyebrow { margin: 22px 0 8px; color: var(--amber); font-size: .79rem; font-weight: 800; letter-spacing: 0; text-transform: uppercase; }
.eyebrow.dark { color: #9b6500; margin-top: 0; }
h1, h2, p { letter-spacing: 0; }
h1 { font-size: clamp(2.3rem, 7vw, 5.3rem); line-height: .98; max-width: 900px; margin: 0; }
.hero-copy { font-size: clamp(1.05rem, 2.2vw, 1.45rem); line-height: 1.5; max-width: 720px; color: #eef0f4; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 26px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 46px; padding: 0 18px; border-radius: 6px; text-decoration: none; font-weight: 750; }
.button.primary { background: var(--amber); color: #161616; }
.button.secondary { border: 1px solid #d8dbe1; color: white; }

.signal-band { display: grid; grid-template-columns: repeat(4, 1fr); max-width: 1180px; margin: 0 auto; border-left: 1px solid var(--line); }
.signal-band div { padding: 28px; border-right: 1px solid var(--line); }
.signal-band strong { display: block; font-size: 1.8rem; color: var(--cyan); }
.signal-band span { color: var(--muted); font-size: .88rem; }

.section { max-width: 1180px; margin: 0 auto; padding: clamp(70px, 10vw, 130px) clamp(20px, 5vw, 70px); }
.intro, .boundary { display: grid; grid-template-columns: minmax(0, 1.1fr) minmax(260px, .9fr); gap: clamp(30px, 8vw, 100px); align-items: start; }
h2 { font-size: clamp(1.85rem, 4vw, 3.3rem); line-height: 1.08; margin: 0 0 20px; }
.intro > p, .boundary > p, .feature-copy > p, .document-lede { color: var(--muted); font-size: 1.08rem; line-height: 1.72; }

.feature-band { display: grid; grid-template-columns: minmax(300px, .9fr) minmax(360px, 1.1fr); align-items: center; gap: clamp(36px, 8vw, 110px); padding: clamp(70px, 9vw, 120px) max(6vw, calc((100vw - 1180px) / 2)); }
.feature-band figure { margin: 0; }
.feature-band figure img { max-height: 760px; width: 100%; object-fit: contain; object-position: center; filter: drop-shadow(0 24px 34px rgba(13, 16, 20, .18)); }
.feature-band figcaption { margin-top: 12px; color: var(--muted); text-align: center; font-size: .8rem; }
.atlas-band { background: #f0f4f5; }
.pulse-band { background: #fff8e8; }
.evidence-band { background: #f6f1f5; }
.index { display: block; font: 700 3rem/1 ui-monospace, "SFMono-Regular", monospace; color: var(--red); margin-bottom: 28px; }
.feature-copy ul { padding-left: 20px; line-height: 1.9; }
.feature-copy li::marker { color: var(--cyan); }
.boundary { border-top: 1px solid var(--line); }

.document-shell { max-width: 880px; margin: 0 auto; padding: clamp(65px, 9vw, 120px) 24px; }
.document-shell h1 { font-size: clamp(2.5rem, 7vw, 4.7rem); margin-bottom: 28px; }
.document-shell section { padding: 30px 0; border-top: 1px solid var(--line); }
.document-shell h2 { font-size: 1.35rem; margin-bottom: 10px; }
.document-shell section p { color: #4f535b; line-height: 1.72; margin: 0; }
.document-shell code { background: #e8eaee; padding: 2px 5px; border-radius: 3px; overflow-wrap: anywhere; }
.contact .button { margin-top: 22px; }

footer { min-height: 110px; padding: 28px clamp(20px, 5vw, 74px); background: var(--graphite); color: #d7dae0; display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 18px; font-size: .86rem; }
footer a { color: white; }

@media (max-width: 760px) {
  .site-header { height: auto; min-height: 66px; padding: 12px 18px; }
  .brand span { display: none; }
  nav { gap: 14px; }
  .hero { min-height: calc(82vh - 66px); background-position: 58% top; }
  .hero-content { padding: 50px 0; }
  .hero-icon { width: 72px; height: 72px; border-radius: 16px; }
  .signal-band { grid-template-columns: 1fr 1fr; }
  .signal-band div { padding: 20px; border-bottom: 1px solid var(--line); }
  .intro, .boundary, .feature-band { grid-template-columns: 1fr; }
  .feature-band { padding-left: 20px; padding-right: 20px; }
  .pulse-band figure { order: 2; }
  .feature-band figure img { max-height: 620px; }
  footer { justify-content: flex-start; }
}