:root {
  --blue: #2F5BE5;
  --blue-dark: #1F47C9;
  --blue-tint: #E8EDFD;
  --ink: #0E0E10;
  --ink-2: #3A3A3E;
  --muted: #8A8A90;
  --line: #E5E5EA;
  --bg: #FFFFFF;
  --bg-soft: #FAFAFB;
  --max: 820px;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}
* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
body {
  font-family: "Arial", "Helvetica Neue", "Hiragino Sans", "Hiragino Kaku Gothic ProN", "Yu Gothic", "Meiryo", sans-serif;
  color: var(--ink-2);
  background: var(--bg);
  line-height: 1.95;
  font-size: 15px;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,0.92);
  backdrop-filter: saturate(180%) blur(14px);
  -webkit-backdrop-filter: saturate(180%) blur(14px);
  border-bottom: 1px solid var(--line);
}
.nav {
  max-width: 1100px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 16px 32px;
}
.brand {
  display: flex; align-items: center; gap: 16px;
  text-decoration: none;
}
.brand img { height: 28px; width: auto; display: block; transition: opacity .2s ease; }
.brand:hover img { opacity: 0.78; }
.brand .tag { color: var(--muted); font-weight: 700; font-size: 11px; letter-spacing: 0.14em; border-left: 1px solid var(--line); padding-left: 14px; }
.back-link {
  color: var(--muted); font-size: 13px; font-weight: 700; letter-spacing: 0.06em;
  transition: color .2s ease;
  display: inline-flex; align-items: center; gap: 6px;
}
.back-link:hover { color: var(--ink); }
.back-link .arrow { transition: transform .2s var(--ease); display: inline-block; }
.back-link:hover .arrow { transform: translateX(-4px); }
@media (max-width: 760px){
  .nav { padding: 14px 20px; }
  .brand .tag { display: none; }
  .brand img { height: 22px; }
}

/* Hero */
.page-hero {
  padding: 96px 32px 64px;
  border-bottom: 1px solid var(--line);
  background: linear-gradient(180deg, #fff 0%, #f8faff 100%);
  text-align: left;
}
.page-hero .container { max-width: var(--max); margin: 0 auto; }
.eyebrow {
  display: inline-block;
  color: var(--blue); font-weight: 700;
  font-size: 12px; letter-spacing: 0.18em;
  margin-bottom: 20px;
}
.eyebrow::before { content: "— "; }
h1.page-title {
  color: var(--ink);
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 700; line-height: 1.2; letter-spacing: 0.01em;
  margin-bottom: 24px;
}
.page-lede { color: var(--muted); font-size: 15px; max-width: 640px; line-height: 1.95; }
@media (max-width: 760px){ .page-hero { padding: 56px 20px 48px; } }

/* Body */
.doc { padding: 80px 32px 120px; }
.doc .container { max-width: var(--max); margin: 0 auto; }
.doc h2 {
  color: var(--ink);
  font-size: 18px; font-weight: 700;
  line-height: 1.6; letter-spacing: 0.02em;
  margin: 56px 0 16px;
  padding-top: 32px;
  border-top: 1px solid var(--line);
}
.doc h2:first-of-type { margin-top: 0; padding-top: 0; border-top: 0; }
.doc h2 .num { color: var(--blue); margin-right: 8px; letter-spacing: 0.04em; }
.doc p { margin-bottom: 16px; color: var(--ink-2); }
.doc ol, .doc ul { margin: 12px 0 16px 24px; }
.doc ol li, .doc ul li { margin-bottom: 8px; color: var(--ink-2); }
.doc ol ol, .doc ol ul, .doc ul ol, .doc ul ul { margin-top: 8px; }
.doc .lead-in { color: var(--ink-2); font-size: 15px; line-height: 1.95; margin-bottom: 48px; }
.doc .meta {
  margin-top: 64px; padding-top: 32px;
  border-top: 1px solid var(--line);
  color: var(--muted); font-size: 13px;
}
.doc .meta b { color: var(--ink); font-weight: 700; }
.contact-block {
  margin-top: 24px;
  padding: 20px 24px;
  background: var(--bg-soft);
  border-radius: 10px;
  color: var(--ink-2); font-size: 14px; line-height: 1.85;
}
.contact-block b { color: var(--ink); font-weight: 700; }
.contact-block a { color: var(--blue); text-decoration: underline; text-underline-offset: 3px; }

@media (max-width: 760px){ .doc { padding: 56px 20px 80px; } }

/* Footer */
footer { background: #fff; padding: 40px 32px; border-top: 1px solid var(--line); }
.footer-inner { max-width: 1100px; margin: 0 auto; display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; align-items: center; }
.footer-brand .name { color: var(--ink); font-weight: 700; letter-spacing: 0.12em; font-size: 14px; }
.footer-brand .copy { color: var(--muted); font-size: 12px; margin-top: 2px; }
.footer-meta { color: var(--muted); font-size: 12px; }

/* SP typography refinements */
h1, h2, h3, .page-title {
  text-wrap: balance;
  word-break: auto-phrase;
}
p, .page-lede, .lead-in {
  text-wrap: pretty;
  word-break: auto-phrase;
}
@media (max-width: 720px) {
  .page-title { font-size: clamp(28px, 7.4vw, 56px); }
}