/* DatumHarbor — root site stylesheet.
   Shares the visual language of the *.datumharbor.com experiment properties:
   light surface, system font stack, single accent colour. No framework. */

:root {
  --project-color: #22315e;
  --accent-soft: #eef1f8;
  --ink: #1a1a2e;
  --ink-soft: #55607a;
  --line: #e0e3ea;
  --bg: #fafafa;
  --surface: #ffffff;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { font-size: 16px; -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  line-height: 1.65;
  color: var(--ink);
  background: var(--bg);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a { color: var(--project-color); text-decoration: none; }
a:hover { text-decoration: underline; }

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

h1, h2, h3 { line-height: 1.25; margin-bottom: 0.5em; color: var(--ink); }
h1 { font-size: 2.25rem; letter-spacing: -0.01em; }
h2 { font-size: 1.5rem; margin-top: 2.25rem; }
h3 { font-size: 1.125rem; margin-top: 1.5rem; }
p { margin-bottom: 1rem; }
ul, ol { padding-left: 1.35em; margin-bottom: 1rem; }
li { margin-bottom: 0.35em; }

code {
  font-family: 'SF Mono', 'Fira Code', Consolas, monospace;
  font-size: 0.88em;
  background: var(--accent-soft);
  padding: 0.15em 0.4em;
  border-radius: 4px;
}

.wrap { max-width: 1100px; margin: 0 auto; padding: 0 1.5rem; width: 100%; }
.narrow { max-width: 780px; }

/* ---------- header ---------- */

.site-header {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
  padding-top: 0.9rem;
  padding-bottom: 0.9rem;
}

.brand {
  display: flex;
  align-items: baseline;
  gap: 0.6rem;
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.01em;
  color: var(--ink);
}
.brand:hover { text-decoration: none; }
.brand .mark {
  width: 0.7rem;
  height: 0.7rem;
  border-radius: 2px;
  background: var(--project-color);
  display: inline-block;
}
.brand .kicker {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--ink-soft);
}

.site-nav { display: flex; gap: 1.35rem; flex-wrap: wrap; font-size: 0.925rem; }
.site-nav a { color: var(--ink-soft); }
.site-nav a:hover { color: var(--project-color); }
.site-nav a[aria-current="page"] { color: var(--project-color); font-weight: 600; }

/* ---------- hero ---------- */

.hero {
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  padding: 3.5rem 0 3rem;
}
.hero .eyebrow {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--project-color);
  margin-bottom: 0.9rem;
}
.hero h1 { font-size: 2.6rem; margin-bottom: 1rem; }
.hero .statement {
  font-size: 1.2rem;
  color: var(--ink-soft);
  max-width: 44em;
  margin-bottom: 0;
}

/* ---------- layout ---------- */

main { flex: 1; padding: 3rem 0 4rem; }
.section { margin-bottom: 3rem; }
.section:last-child { margin-bottom: 0; }
.lede { font-size: 1.05rem; color: var(--ink-soft); max-width: 44em; }

/* ---------- cards ---------- */

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
  margin: 1.5rem 0 0;
}

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
  padding: 1.25rem 1.35rem;
}
.card h3 { margin-top: 0; font-size: 1.05rem; }
.card p { margin-bottom: 0; font-size: 0.925rem; color: var(--ink-soft); }

/* ---------- tables ---------- */

.table-scroll { overflow-x: auto; margin: 1.25rem 0 0; }

table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.925rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
}
th, td { padding: 0.7em 0.9em; text-align: left; border-bottom: 1px solid var(--line); vertical-align: top; }
th { font-weight: 600; background: var(--accent-soft); white-space: nowrap; }
tbody tr:last-child td { border-bottom: 0; }
td code { background: transparent; padding: 0; font-size: 0.95em; }

/* ---------- status / notice ---------- */

.notice {
  background: var(--accent-soft);
  border-left: 3px solid var(--project-color);
  border-radius: 0 8px 8px 0;
  padding: 1.1rem 1.3rem;
  margin: 1.5rem 0 0;
}
.notice p:last-child { margin-bottom: 0; }
.notice .label {
  display: block;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--project-color);
  margin-bottom: 0.35rem;
}

.badge {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  padding: 0.2em 0.55em;
  border-radius: 4px;
  background: var(--accent-soft);
  color: var(--project-color);
  white-space: nowrap;
}

.principle { border-top: 1px solid var(--line); padding: 1rem 0; }
.principle:first-of-type { border-top: 0; }
.principle dt { font-weight: 700; font-size: 0.98rem; }
.principle dt span { color: var(--ink-soft); font-weight: 600; margin-right: 0.5rem; }
.principle dd { color: var(--ink-soft); margin: 0.2rem 0 0; }

dl { margin: 0; }
dt { font-weight: 600; }
dd { margin: 0 0 0.75rem; color: var(--ink-soft); }

/* ---------- footer ---------- */

.site-footer {
  background: var(--surface);
  border-top: 1px solid var(--line);
  padding: 2rem 0;
  font-size: 0.875rem;
  color: var(--ink-soft);
}
.site-footer .wrap {
  display: flex;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
}
.site-footer a { color: var(--ink-soft); }
.site-footer a:hover { color: var(--project-color); }
.site-footer .principles-line { margin-top: 0.35rem; }

/* ---------- utilities ---------- */

.sr-only {
  position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px;
  overflow: hidden; clip: rect(0,0,0,0); border: 0;
}
:focus-visible { outline: 2px solid var(--project-color); outline-offset: 2px; }
.muted { color: var(--ink-soft); }
.stack-sm > * + * { margin-top: 0.5rem; }

@media (max-width: 768px) {
  html { font-size: 15.5px; }
  .hero { padding: 2.5rem 0 2rem; }
  .hero h1 { font-size: 1.9rem; }
  .hero .statement { font-size: 1.05rem; }
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.3rem; }
  main { padding: 2.25rem 0 3rem; }
  .site-header .wrap { gap: 0.75rem; }
}