/* Keystone public site — brand tokens from brand/README.md. */
:root {
  --paper: #fbfbfc; --panel: #ffffff; --ink: #15181d; --muted: #596070;
  --line: #e3e6ea; --chip: #f0f2f4;
  --brand: #1e6e59; --signal: #2fa37d; --deep: #123f32; --on-brand: #ffffff; --link: #1e6e59;
  --logo-light: block; --logo-dark: none;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --paper: #0e1013; --panel: #15181d; --ink: #e9eaec; --muted: #9aa1ad;
    --line: #262b32; --chip: #1c2026;
    --brand: #2a8468; --signal: #3fbe93; --deep: #0b2a21; --on-brand: #ffffff; --link: #3fbe93;
    --logo-light: none; --logo-dark: block;
  }
}
:root[data-theme="dark"] {
  --paper: #0e1013; --panel: #15181d; --ink: #e9eaec; --muted: #9aa1ad;
  --line: #262b32; --chip: #1c2026;
  --brand: #2a8468; --signal: #3fbe93; --deep: #0b2a21; --on-brand: #ffffff; --link: #3fbe93;
  --logo-light: none; --logo-dark: block;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0; background: var(--paper); color: var(--ink);
  font: 16px/1.6 Inter, "Helvetica Neue", Arial, sans-serif;
}
a { color: var(--link); }
img { max-width: 100%; }
.wrap { max-width: 960px; margin: 0 auto; padding: 0 16px; }
.muted { color: var(--muted); }
.small { font-size: 14px; }

/* Header */
.site-header { border-bottom: 1px solid var(--line); }
.site-header .wrap { display: flex; align-items: center; gap: 20px; min-height: 64px; flex-wrap: wrap; }
.logo { display: flex; align-items: center; }
.logo img { height: 30px; width: auto; }
.logo .light { display: var(--logo-light); }
.logo .dark { display: var(--logo-dark); }
.site-nav { display: flex; gap: 18px; margin-left: auto; align-items: center; flex-wrap: wrap; }
.site-nav a { color: var(--ink); text-decoration: none; font-weight: 500; font-size: 15px; }
.site-nav a:hover { color: var(--link); }
.site-nav a[aria-current="page"] { color: var(--link); }

/* Buttons */
.cta {
  display: inline-block; background: var(--brand); color: var(--on-brand);
  text-decoration: none; font-weight: 600; padding: 11px 20px; border-radius: 8px;
  border: 0; font: inherit; font-weight: 600; cursor: pointer;
}
.cta:hover { background: var(--deep); }
.cta.ghost { background: transparent; color: var(--link); border: 1px solid var(--line); }
.cta.ghost:hover { border-color: var(--brand); background: transparent; }
.site-nav .cta { color: var(--on-brand); padding: 8px 14px; }

/* Hero */
.hero { padding: 64px 0 40px; }
.kicker { color: var(--link); font-weight: 600; letter-spacing: .06em; text-transform: uppercase; font-size: 13px; margin: 0; }
h1 { font-size: clamp(30px, 5.5vw, 46px); line-height: 1.12; letter-spacing: -.02em; margin: 10px 0 16px; font-weight: 600; }
.lead { font-size: 19px; color: var(--muted); max-width: 64ch; margin: 0 0 28px; }
.actions { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }

/* Sections */
section { padding: 36px 0; }
h2 { font-size: 26px; letter-spacing: -.01em; margin: 0 0 8px; font-weight: 600; }
h3 { font-size: 16px; margin: 0 0 6px; font-weight: 600; }
.section-lead { color: var(--muted); max-width: 64ch; margin: 0 0 24px; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 14px; }
.card { background: var(--panel); border: 1px solid var(--line); border-radius: 10px; padding: 18px 20px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }
.grid.two { grid-template-columns: repeat(auto-fit, minmax(min(100%, 360px), 1fr)); }

/* Flow diagram: sensors → Keystone → consumers */
.flow { display: grid; grid-template-columns: 1fr auto 1fr auto 1fr; gap: 12px; align-items: center; }
.flow .col { display: grid; gap: 8px; }
.flow .node { background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 8px 12px; font-size: 14px; }
.flow .node strong { display: block; font-size: 14px; }
.flow .node span { color: var(--muted); font-size: 13px; }
.flow .hub { background: var(--deep); color: #e9f3ef; border: 0; text-align: center; padding: 22px 16px; border-radius: 10px; }
.flow .hub strong { font-size: 18px; color: #fff; }
.flow .hub span { color: #b9d6cb; }
.flow .arrow { color: var(--muted); font-size: 22px; text-align: center; }
.flow .label { font-size: 12px; text-transform: uppercase; letter-spacing: .06em; color: var(--muted); font-weight: 600; }
@media (max-width: 720px) {
  .flow { grid-template-columns: 1fr; }
  .flow .arrow { transform: rotate(90deg); }
}

/* Status table */
.status { width: 100%; border-collapse: collapse; background: var(--panel); border: 1px solid var(--line); border-radius: 10px; overflow: hidden; }
.status th, .status td { text-align: left; padding: 12px 16px; border-bottom: 1px solid var(--line); vertical-align: top; font-size: 15px; }
.status tr:last-child td { border-bottom: 0; }
.status th { font-size: 13px; color: var(--muted); font-weight: 600; text-transform: uppercase; letter-spacing: .04em; }
.pill { display: inline-block; font-size: 12px; line-height: 1.4; font-weight: 600; padding: 3px 9px; border-radius: 12px; }
.status td:last-child { width: 40%; }
.pill.done { background: var(--brand); color: var(--on-brand); }
.pill.next { background: var(--chip); color: var(--muted); border: 1px solid var(--line); }

/* Demo band */
.band { background: var(--deep); color: #e9f3ef; border-radius: 12px; padding: 28px; display: flex; gap: 20px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.band h2 { color: #fff; }
.band p { margin: 0; color: #b9d6cb; max-width: 56ch; }
.band .cta { background: #3fbe93; color: #0e1013; }
.band .cta:hover { background: #fff; }

/* Long-form (visitor guide) */
.prose { max-width: 70ch; padding: 48px 0 24px; }
.prose h1 { font-size: clamp(28px, 5vw, 38px); }
.prose h2 { font-size: 22px; margin: 36px 0 10px; }
.prose p, .prose li { font-size: 17px; }
.prose ul, .prose ol { padding-left: 22px; }
.prose li { margin: 6px 0; }
.callout { background: var(--chip); border: 1px solid var(--line); border-left: 4px solid var(--brand); border-radius: 8px; padding: 14px 18px; margin: 20px 0; }

/* Login */
.login-body { min-height: 100vh; display: grid; place-items: center; padding: 16px; }
.login { width: 100%; max-width: 400px; background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 28px; }
.login .brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); margin-bottom: 18px; }
.login .brand .name { font-weight: 600; font-size: 20px; }
.login .brand .parent { color: var(--muted); font-size: 13px; border-left: 1px solid var(--line); padding-left: 10px; }
.login h1 { font-size: 24px; margin: 0 0 6px; }
.login form { display: grid; gap: 10px; margin: 18px 0; }
.login label { font-weight: 600; font-size: 14px; }
.login input { font: inherit; padding: 10px 12px; border: 1px solid var(--line); border-radius: 8px; background: var(--paper); color: var(--ink); }
.login input:focus { outline: 2px solid var(--signal); outline-offset: 1px; }
.login .cta { width: 100%; }
.error { color: #b4442e; background: color-mix(in srgb, #b4442e 10%, transparent); border-radius: 8px; padding: 10px 12px; margin: 12px 0 0; font-size: 14px; }

/* Footer */
.site-footer { border-top: 1px solid var(--line); margin-top: 48px; padding: 24px 0 40px; color: var(--muted); font-size: 14px; }
.site-footer .wrap { display: flex; gap: 16px; flex-wrap: wrap; justify-content: space-between; }
.site-footer a { color: var(--muted); }