:root {
  color-scheme: light;
  --ink: #202530;
  --muted: #667487;
  --line: #dee3ea;
  --paper: #ffffff;
  --fog: #f4f6f9;
  --red: #c6383e;
  --navy: #202e42;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--fog);
  color: var(--ink);
  font: 16px/1.8 system-ui, -apple-system, "Segoe UI", "Noto Sans JP", sans-serif;
}
a { color: #17558a; text-underline-offset: 3px; }
a:hover { opacity: .88; }
.container { width: min(100% - 36px, 980px); margin: 0 auto; }
.site-header { padding: 19px 0; background: var(--paper); border-bottom: 1px solid var(--line); }
.nav { display: flex; justify-content: space-between; align-items: center; gap: 18px; flex-wrap: wrap; }
.brand { font-size: 16px; font-weight: 800; color: var(--navy); text-decoration: none; }
.nav-links { display: flex; flex-wrap: wrap; align-items: center; gap: 15px; font-size: 13px; }
.hero { padding: 66px 0 52px; background: linear-gradient(155deg, #fff 10%, #f7f8fb 74%); }
.eyebrow { color: var(--red); font-weight: 800; font-size: 13px; letter-spacing: .04em; margin: 0 0 12px; }
h1 { font-size: clamp(30px, 5vw, 46px); line-height: 1.4; margin: 0 0 20px; letter-spacing: -.025em; }
h2 { font-size: 26px; margin: 0 0 18px; line-height: 1.45; }
h3 { font-size: 18px; margin: 0 0 10px; }
.lede { font-size: 18px; color: #415066; max-width: 770px; margin: 0 0 25px; }
.hero-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 13px; }
.button { display: inline-flex; padding: 12px 22px; border-radius: 9px; text-decoration: none; font-weight: 750; justify-content: center; align-items: center; }
.button-primary { color: white; background: var(--red); }
.button-secondary { color: var(--navy); background: white; border: 1px solid var(--line); }
.subtle { font-size: 13px; color: var(--muted); }
section.content { padding: 50px 0; }
section.content + section.content { border-top: 1px solid var(--line); }
.grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; }
.card { background: var(--paper); border: 1px solid var(--line); border-radius: 14px; padding: 22px; }
.card p { color: var(--muted); margin: 0; }
.label { color: var(--red); font-size: 13px; font-weight: 850; }
.steps { display: grid; gap: 14px; list-style: none; margin: 20px 0; padding: 0; counter-reset: steps; }
.steps > li { counter-increment: steps; position: relative; background: var(--paper); border: 1px solid var(--line); border-radius: 12px; padding: 18px 20px 18px 64px; }
.steps > li::before { content: counter(steps); position: absolute; top: 17px; left: 17px; width: 30px; height: 30px; border-radius: 50%; background: #e9eff7; color: #1b4a73; font-weight: 850; text-align: center; line-height: 30px; }
.steps strong { display: block; }
code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; padding: 3px 6px; background: #e8edf4; border-radius: 5px; overflow-wrap: anywhere; font-size: .91em; }
.notice { padding: 17px 20px; border: 1px solid #dfcfaa; background: #fffbf0; border-radius: 10px; font-size: 14px; }
.ok-notice { border-color: #c8ddce; background: #f4faf6; }
.table-wrap { overflow-x: auto; }
table { border-collapse: collapse; width: 100%; background: var(--paper); font-size: 14px; }
th, td { padding: 12px 14px; border: 1px solid var(--line); text-align: left; vertical-align: top; }
th { background: #edf1f6; }
.footer { padding: 28px 0 45px; border-top: 1px solid var(--line); color: var(--muted); font-size: 13px; }
.hash { display: block; overflow-wrap: anywhere; word-break: break-all; padding: 10px; background: #e8edf4; border-radius: 8px; font: 12px/1.65 ui-monospace, monospace; }
.callout { background: white; padding: 22px; border: 1px solid var(--line); border-radius: 12px; }
.small { font-size: 13px; }
ul { padding-left: 1.3em; }
@media (max-width: 680px) {
  .hero { padding: 45px 0; }
  .grid { grid-template-columns: 1fr; }
  .hero-actions .button { width: 100%; }
  section.content { padding: 35px 0; }
  h2 { font-size: 23px; }
}