/* AWS-native landing page. White ground, navy type, orange as a scarce accent.
   No external fonts. Amazon Ember first, system fallback. */

:root {
  --aws-orange: #FF9900;
  --aws-orange-hover: #EC7211;
  --aws-navy: #232F3E;
  --aws-ink: #161E2D;
  --aws-blue: #146EB4;
  --aws-blue-dark: #0F5A94;
  --aws-neutral-50: #FAFAFA;
  --aws-neutral-100: #F2F3F3;
  --aws-neutral-200: #E9ECEF;
  --aws-neutral-300: #D5DBDB;
  --aws-neutral-500: #687078;
  --aws-success: #1E8E3E;
  --aws-error: #D13212;

  --font-heading: "Amazon Ember", "Amazon Ember Display", "Helvetica Neue", Arial, sans-serif;
  --font-body: "Amazon Ember", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "Amazon Ember Mono", ui-monospace, "SFMono-Regular", Menlo, Consolas, monospace;

  --radius-sm: 2px;
  --radius-md: 4px;
  --radius-lg: 8px;

  --shadow-sub: 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 10px 28px rgba(22, 30, 45, 0.12);

  --container: 1120px;
  --gutter: clamp(16px, 4vw, 40px);
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: #fff;
  color: var(--aws-navy);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

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

a { color: var(--aws-blue); text-underline-offset: 2px; }
a:hover { color: var(--aws-blue-dark); }

::selection { background: var(--aws-orange); color: var(--aws-ink); }

/* ---------- Topbar ---------- */

.topbar {
  position: sticky; top: 0; z-index: 20;
  background: var(--aws-navy);
  color: #fff;
}
.topbar__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 14px var(--gutter);
  display: flex; align-items: center; gap: 24px;
  justify-content: space-between;
}
.topbar__brand { display: inline-flex; align-items: center; }
.topbar__brand img { filter: none; }
.topbar__nav {
  display: flex; gap: 4px; flex-wrap: wrap;
}
.topbar__nav a {
  color: #fff;
  text-decoration: none;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.01em;
}
.topbar__nav a:hover { background: rgba(255,255,255,0.08); color: #fff; }
.topbar__nav a:focus-visible {
  outline: 2px solid var(--aws-orange);
  outline-offset: 2px;
}
.topbar__ribbon {
  height: 3px;
  background: linear-gradient(90deg,
    var(--aws-orange) 0 18%,
    var(--aws-orange) 18% 22%,
    transparent 22% 100%);
}

/* ---------- Shared ---------- */

.band { padding: clamp(48px, 8vw, 88px) 0; background: #fff; }
.band--alt { background: var(--aws-neutral-100); }
.band--credentials {
  padding: 32px 0;
  background: #fff;
  border-top: 1px solid var(--aws-neutral-200);
  border-bottom: 1px solid var(--aws-neutral-200);
}
.band__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.kicker {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--aws-blue);
  font-weight: 500;
  margin-bottom: 12px;
}
.kicker--light { color: var(--aws-orange); }

.h2 {
  font-family: var(--font-heading);
  color: var(--aws-ink);
  font-weight: 700;
  font-size: clamp(26px, 3.4vw, 36px);
  line-height: 1.2;
  letter-spacing: -0.01em;
  margin: 0 0 20px;
}
.h2--small { font-size: 14px; color: var(--aws-neutral-500); font-weight: 500; letter-spacing: 0.12em; text-transform: uppercase; margin-bottom: 16px; }
.h2--on-dark { color: #fff; }

.lede {
  font-size: 17px;
  max-width: 68ch;
  color: var(--aws-navy);
  margin: 0 0 24px;
}

/* ---------- Hero ---------- */

.hero {
  max-width: var(--container);
  margin: 0 auto;
  padding: clamp(40px, 7vw, 88px) var(--gutter) clamp(40px, 6vw, 72px);
}
.hero__meta {
  display: flex; flex-wrap: wrap; gap: 8px;
  margin-bottom: 24px;
}
.chip {
  display: inline-flex; align-items: center;
  padding: 6px 10px;
  border-radius: 999px;
  background: #fff;
  border: 1px solid var(--aws-neutral-300);
  font-size: 12px;
  color: var(--aws-navy);
  line-height: 1;
}
.chip--mono { font-family: var(--font-mono); letter-spacing: 0.02em; }

.hero__h1 {
  font-family: var(--font-heading);
  color: var(--aws-ink);
  font-weight: 700;
  font-size: clamp(34px, 6vw, 64px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  margin: 0 0 20px;
  max-width: 22ch;
}
.hero__sub {
  font-size: clamp(17px, 1.6vw, 19px);
  color: var(--aws-navy);
  max-width: 62ch;
  margin: 0 0 32px;
  line-height: 1.55;
}
.hero__ctas {
  display: flex; flex-wrap: wrap; gap: 12px;
  margin-bottom: 48px;
}

/* Buttons */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 12px 20px;
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-weight: 700;
  font-size: 15px;
  line-height: 1;
  text-decoration: none;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color 160ms ease, color 160ms ease, border-color 160ms ease, transform 80ms ease;
  min-height: 44px;
}
.btn:focus-visible {
  outline: 2px solid var(--aws-ink);
  outline-offset: 2px;
}
.btn--primary {
  background: var(--aws-orange);
  color: var(--aws-ink);
  border-color: var(--aws-orange);
  box-shadow: var(--shadow-sub);
}
.btn--primary:hover { background: var(--aws-orange-hover); border-color: var(--aws-orange-hover); color: #fff; }
.btn--primary:active { transform: translateY(1px); }
.btn--ghost {
  background: #fff;
  color: var(--aws-ink);
  border-color: var(--aws-neutral-300);
}
.btn--ghost:hover { border-color: var(--aws-ink); }
.btn--ghost.btn--on-dark {
  background: transparent;
  color: #fff;
  border-color: rgba(255,255,255,0.4);
}
.btn--ghost.btn--on-dark:hover { border-color: #fff; }
.btn--lg { padding: 16px 24px; font-size: 16px; }

/* Stat strip */
.stat-strip {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  margin: 0;
  border: 1px solid var(--aws-neutral-200);
  border-radius: var(--radius-md);
  overflow: hidden;
  background: #fff;
}
.stat {
  padding: 20px 24px;
  border-right: 1px solid var(--aws-neutral-200);
}
.stat:last-child { border-right: 0; }
.stat dt {
  font-size: 12px;
  font-family: var(--font-mono);
  color: var(--aws-neutral-500);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-bottom: 8px;
}
.stat dd {
  margin: 0;
  font-family: var(--font-heading);
  color: var(--aws-ink);
  font-weight: 700;
  font-size: clamp(22px, 3vw, 30px);
  letter-spacing: -0.01em;
  font-variant-numeric: tabular-nums;
}

/* ---------- Context band ---------- */

.context-grid {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 40px;
  align-items: start;
}
.signal-list {
  list-style: none; margin: 0; padding: 0;
  display: grid; gap: 12px;
}
.signal-list li {
  background: #fff;
  border: 1px solid var(--aws-neutral-200);
  border-left: 3px solid var(--aws-orange);
  border-radius: var(--radius-md);
  padding: 14px 16px;
  font-size: 15px;
  line-height: 1.5;
}
.signal-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  background: var(--aws-neutral-100);
  color: var(--aws-navy);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  margin-right: 8px;
  font-weight: 500;
}

/* ---------- Frame grid ---------- */

.frame-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 24px;
}
.frame-card {
  background: #fff;
  border: 1px solid var(--aws-neutral-200);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sub);
  position: relative;
  display: flex; flex-direction: column; gap: 10px;
}
.frame-card__head { display: flex; align-items: baseline; gap: 12px; }
.frame-card__num {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: 44px;
  letter-spacing: -0.03em;
  color: var(--aws-ink);
  font-variant-numeric: tabular-nums;
  line-height: 1;
}
.frame-card__num span { font-size: 22px; color: var(--aws-neutral-500); font-weight: 500; margin-left: 2px; }
.frame-card h3 {
  font-family: var(--font-heading);
  font-size: 16px;
  font-weight: 700;
  color: var(--aws-navy);
  margin: 0;
}
.frame-card p { margin: 0; color: var(--aws-navy); font-size: 15px; }
.frame-card--mid { border-top: 3px solid var(--aws-blue); }
.frame-card--ai {
  border-top: 3px solid var(--aws-orange);
  background: linear-gradient(180deg, #fff 0%, #FFF7EC 100%);
}

/* ---------- Architecture diagram ---------- */

.diagram {
  margin: 32px 0 0;
  background: #fff;
  border: 1px solid var(--aws-neutral-200);
  border-radius: var(--radius-md);
  padding: clamp(16px, 3vw, 28px);
  box-shadow: var(--shadow-md);
}
.diagram__grid {
  display: grid; gap: 12px;
}
.diagram__lane {
  display: grid;
  grid-template-columns: 180px 1fr;
  align-items: center;
  gap: 16px;
  padding: 14px;
  border-radius: var(--radius-md);
  background: var(--aws-neutral-50);
  border: 1px solid var(--aws-neutral-200);
}
.lane__label {
  font-family: var(--font-mono);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--aws-navy);
  font-weight: 500;
  padding: 8px 10px;
  background: #fff;
  border: 1px solid var(--aws-neutral-200);
  border-radius: var(--radius-sm);
  text-align: center;
}
.lane__nodes { display: flex; flex-wrap: wrap; gap: 8px; }
.node {
  display: inline-flex; align-items: center;
  padding: 8px 12px;
  border-radius: var(--radius-sm);
  background: #fff;
  border: 1px solid var(--aws-neutral-300);
  font-size: 13px;
  font-family: var(--font-mono);
  color: var(--aws-ink);
  box-shadow: var(--shadow-sub);
}
.lane--ai { background: #FFF7EC; border-color: #FFDBA3; }
.lane--ai .lane__label { color: var(--aws-ink); border-color: #FFDBA3; }
.lane--ai .node { border-color: #FFDBA3; }

.lane--rules { background: #EEF5FB; border-color: #BFD8EC; }
.lane--rules .lane__label { color: var(--aws-blue-dark); border-color: #BFD8EC; }
.lane--rules .node { border-color: #BFD8EC; }

.lane--code { background: var(--aws-neutral-50); }

.diagram__base {
  display: flex; flex-wrap: wrap; gap: 8px;
  padding: 12px 14px;
  background: var(--aws-navy);
  color: #fff;
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  margin-top: 4px;
  justify-content: space-between;
}
.diagram__base span {
  padding: 4px 8px;
  border: 1px solid rgba(255,255,255,0.18);
  border-radius: var(--radius-sm);
}

.diagram figcaption {
  margin-top: 16px;
  color: var(--aws-neutral-500);
  font-size: 14px;
  font-style: normal;
  max-width: 80ch;
}

/* ---------- Proof ---------- */

.proof-grid {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 40px;
  align-items: start;
}
.proof-copy p {
  font-size: 17px;
  margin: 0 0 16px;
  color: var(--aws-navy);
  max-width: 58ch;
}
.credential-line {
  padding: 12px 14px;
  background: #fff;
  border-left: 3px solid var(--aws-blue);
  border-radius: var(--radius-sm);
  font-size: 15px;
}
.big-stats {
  margin: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--aws-neutral-200);
  border: 1px solid var(--aws-neutral-200);
  border-radius: var(--radius-md);
  overflow: hidden;
}
.big-stats > div {
  background: #fff;
  padding: 22px 20px;
}
.big-stats dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--aws-neutral-500);
  margin-bottom: 8px;
}
.big-stats dd {
  margin: 0;
  font-family: var(--font-heading);
  font-size: clamp(30px, 4vw, 42px);
  font-weight: 700;
  color: var(--aws-ink);
  line-height: 1;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
}
.big-stats dd span { font-size: 18px; color: var(--aws-neutral-500); font-weight: 500; margin-left: 2px; }

/* ---------- Paper ---------- */

.paper-card {
  margin: 0 0 16px;
  background: #fff;
  border: 1px solid var(--aws-neutral-200);
  border-left: 4px solid var(--aws-orange);
  border-radius: var(--radius-md);
  padding: 28px;
  box-shadow: var(--shadow-sub);
}
.paper-card blockquote {
  margin: 0 0 16px;
  font-family: var(--font-heading);
  font-size: 20px;
  line-height: 1.45;
  color: var(--aws-ink);
  font-weight: 400;
  max-width: 60ch;
}
.paper-card__meta {
  display: flex; flex-wrap: wrap; gap: 8px; align-items: center;
}
.pill {
  display: inline-flex; align-items: center;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--aws-neutral-100);
  color: var(--aws-navy);
  font-size: 13px;
  font-family: var(--font-mono);
  text-decoration: none;
  border: 1px solid var(--aws-neutral-200);
}
.pill--link { background: #fff; color: var(--aws-blue); }
.pill--link:hover { color: var(--aws-blue-dark); border-color: var(--aws-blue); }

.aside {
  color: var(--aws-neutral-500);
  font-size: 14px;
  max-width: 70ch;
  margin: 0 0 16px;
}

.extra {
  background: #fff;
  border: 1px solid var(--aws-neutral-200);
  border-radius: var(--radius-md);
  padding: 16px 20px;
  max-width: 720px;
}
.extra summary {
  cursor: pointer;
  font-family: var(--font-heading);
  font-weight: 700;
  color: var(--aws-ink);
  font-size: 15px;
  list-style: none;
  padding: 4px 0;
}
.extra summary::-webkit-details-marker { display: none; }
.extra summary::before {
  content: "+";
  display: inline-block;
  width: 18px;
  color: var(--aws-orange);
  font-weight: 700;
}
.extra[open] summary::before { content: "−"; }
.extra p { margin: 12px 0 0; font-size: 15px; color: var(--aws-navy); }

/* ---------- Routing ---------- */

.routing-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 24px;
}
.routing-card {
  background: #fff;
  border: 1px solid var(--aws-neutral-200);
  border-radius: var(--radius-md);
  padding: 24px;
  box-shadow: var(--shadow-sub);
}
.routing-card h3 {
  font-family: var(--font-heading);
  font-size: 17px;
  color: var(--aws-ink);
  margin: 0 0 10px;
  font-weight: 700;
}
.routing-card p { margin: 0; font-size: 15px; color: var(--aws-navy); }

/* ---------- Credential badge row ---------- */

.badge-row {
  list-style: none; margin: 0; padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 8px;
}
.badge {
  display: flex; flex-direction: column; gap: 2px;
  padding: 10px 14px;
  background: var(--aws-neutral-50);
  border: 1px solid var(--aws-neutral-200);
  border-radius: var(--radius-sm);
}
.badge__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--aws-neutral-500);
  text-transform: uppercase;
}
.badge__v {
  font-size: 14px;
  color: var(--aws-ink);
  font-weight: 500;
  font-family: var(--font-body);
}

/* ---------- CTA ---------- */

.cta {
  background: var(--aws-navy);
  color: #fff;
  padding: clamp(56px, 8vw, 96px) 0;
  position: relative;
  overflow: hidden;
}
.cta::before {
  content: "";
  position: absolute; inset: 0;
  background:
    radial-gradient(ellipse 600px 280px at 15% 110%, rgba(255,153,0,0.18), transparent 60%),
    radial-gradient(ellipse 500px 220px at 90% -10%, rgba(20,110,180,0.22), transparent 60%);
  pointer-events: none;
}
.cta__inner {
  display: grid;
  grid-template-columns: 1.4fr 1fr;
  gap: 40px;
  align-items: start;
  position: relative;
  z-index: 1;
}
.cta__sub {
  font-size: 17px;
  color: rgba(255,255,255,0.82);
  max-width: 58ch;
  margin: 0 0 24px;
}
.cta__actions { display: flex; flex-wrap: wrap; gap: 12px; }

.cta__card {
  background: rgba(255,255,255,0.06);
  border: 1px solid rgba(255,255,255,0.14);
  border-radius: var(--radius-md);
  padding: 20px;
  backdrop-filter: blur(4px);
}
.cta__card-row {
  display: flex; justify-content: space-between; gap: 12px;
  padding: 10px 0;
  border-bottom: 1px dashed rgba(255,255,255,0.14);
  font-size: 14px;
}
.cta__card-row:last-child { border-bottom: 0; }
.cta__card-row span { color: rgba(255,255,255,0.7); font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.08em; text-transform: uppercase; }
.cta__card-row strong { color: #fff; font-weight: 700; text-align: right; }

/* ---------- Footer ---------- */

.foot {
  background: var(--aws-ink);
  color: rgba(255,255,255,0.7);
  padding: 28px 0;
}
.foot__inner {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 var(--gutter);
}
.foot__line {
  margin: 0 0 8px;
  font-size: 14px;
  color: #fff;
}
.foot__line a { color: var(--aws-orange); text-decoration: none; }
.foot__line a:hover { color: #fff; }
.foot__fine {
  margin: 0;
  font-size: 12px;
  color: rgba(255,255,255,0.55);
  max-width: 88ch;
  line-height: 1.5;
}

/* ---------- Responsive ---------- */

@media (max-width: 960px) {
  .context-grid,
  .proof-grid,
  .cta__inner { grid-template-columns: 1fr; }
  .frame-grid,
  .routing-grid { grid-template-columns: 1fr; }
  .badge-row { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 720px) {
  .topbar__inner { flex-direction: column; align-items: flex-start; gap: 12px; padding: 12px var(--gutter); }
  .topbar__nav { gap: 2px; }
  .topbar__nav a { padding: 6px 8px; font-size: 13px; }

  .stat-strip { grid-template-columns: 1fr; }
  .stat { border-right: 0; border-bottom: 1px solid var(--aws-neutral-200); }
  .stat:last-child { border-bottom: 0; }

  .big-stats { grid-template-columns: 1fr; }

  .diagram__lane { grid-template-columns: 1fr; }
  .lane__label { text-align: left; }

  .badge-row { grid-template-columns: 1fr; }

  .hero__h1 { max-width: none; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}