* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 { font-family: var(--serif); font-weight: 800; letter-spacing: -0.025em; margin: 0; }
h1 { font-size: 34px; line-height: 1.12; }
h2 { font-size: 21px; letter-spacing: -0.015em; }
h3 { font-size: 17px; }
p { margin: 0; text-wrap: pretty; }
a { color: var(--ink); }
.mono { font-family: var(--mono); font-variant-numeric: tabular-nums; }
.muted { color: var(--muted); }

.wrap { max-width: var(--wrap); margin: 0 auto; padding: 0 24px; }

/* Global navigation (plan 8-1a): logo, the tool, then trust links. */
.gnb { background: var(--paper); border-bottom: 1px solid var(--rule); }
.gnb-inner { height: 60px; display: flex; align-items: center; gap: 28px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); }
.brand svg { width: 28px; height: 28px; flex: none; }
.brand span { font-family: var(--serif); font-weight: 800; font-size: 19px; letter-spacing: -0.02em; }
.tool-label { font-size: 13.5px; font-weight: 600; color: var(--ink); text-decoration: none;
  border-bottom: 2px solid var(--ink); padding-bottom: 3px; }
.gnb-links { display: flex; gap: 20px; margin-left: auto; font-size: 13px; }
.gnb-links a { color: var(--muted); text-decoration: none; }
.gnb-links a:hover { color: var(--ink); }

main { padding: 28px 0 64px; }
.panel { background: var(--paper); border: 1px solid var(--rule); border-radius: 10px;
  box-shadow: 0 1px 2px rgba(30, 30, 27, 0.04), 0 8px 24px rgba(30, 30, 27, 0.05); }
.stack { display: flex; flex-direction: column; gap: 18px; }

/* The page h1 on the home page: small, above the tool (the tool's step titles are the big headings). */
.home-h1 { font-family: var(--sans); font-size: 14px; font-weight: 600; letter-spacing: 0; color: var(--muted); line-height: 1.4; }

/* The tool mounts here. Without JavaScript the fallback stays visible. */
#tool { min-height: 120px; }
.tool-fallback { padding: 22px 24px; color: var(--muted); font-size: 14px; }

/* Prose block: what it does, the rules, how to read it, limits, an example.
   This is in the first HTML response on purpose (plan 6-1). */
.prose { padding: 26px 28px; display: flex; flex-direction: column; gap: 14px; }
.prose h2 { margin-bottom: 2px; }
.prose h3 { margin-top: 8px; }
.prose p, .prose li { font-size: 14.5px; color: var(--muted); }
.prose strong { color: var(--ink); font-weight: 600; }
.prose ul { margin: 0; padding-left: 20px; display: flex; flex-direction: column; gap: 6px; }
.example { border-left: 2px solid var(--rule); padding-left: 16px; display: flex;
  flex-direction: column; gap: 4px; font-size: 14px; }

.site-foot { border-top: 1px solid var(--rule); background: var(--paper); }
.site-foot .wrap { padding-top: 20px; padding-bottom: 20px; display: flex; gap: 16px;
  align-items: center; font-size: 12.5px; color: var(--muted); flex-wrap: wrap; }
.foot-links { display: flex; gap: 14px; flex-wrap: wrap; }
.foot-links a { color: var(--muted); }
.foot-links a:hover { color: var(--ink); }
.foot-year { margin-left: auto; }

@media (max-width: 720px) {
  .wrap { padding: 0 16px; }
  .gnb-inner { height: 52px; gap: 14px; }
  .gnb-links { display: none; }
  h1 { font-size: 27px; }
  .prose { padding: 20px; }
}