:root {
  --ink: #17252a;
  --muted: #52646a;
  --line: #d9e3e5;
  --bg: #ffffff;
  --band: #f3f7f7;
  --brand: #0f5e6b;
  --brand-ink: #ffffff;
  --accent: #e8f2f3;
  --radius: 12px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --ink: #e6eef0;
    --muted: #a7b8bc;
    --line: #2c3c40;
    --bg: #0f181b;
    --band: #152226;
    --brand: #4fb3c2;
    --brand-ink: #0b1416;
    --accent: #1b2d32;
  }
}
* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", "Segoe UI", sans-serif;
  font-size: 17px;
  line-height: 1.75;
  overflow-wrap: anywhere;
}
a { color: var(--brand); }
img { max-width: 100%; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 16px; }
.skip { position: absolute; left: -999px; }
.skip:focus { left: 16px; top: 8px; background: var(--bg); padding: 6px 10px; z-index: 10; }

.top { border-bottom: 1px solid var(--line); background: var(--bg); position: sticky; top: 0; z-index: 5; }
.top-in { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 8px 20px; padding-top: 12px; padding-bottom: 12px; }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; color: var(--ink); font-weight: 700; font-size: 18px; line-height: 1.2; }
.brand small { display: block; font-weight: 500; font-size: 12px; color: var(--muted); letter-spacing: .02em; }
.nav { display: flex; flex-wrap: wrap; gap: 4px 16px; font-size: 15px; }
.nav a { color: var(--ink); text-decoration: none; padding: 4px 0; }
.nav a[aria-current="page"], .nav a:hover { color: var(--brand); text-decoration: underline; text-underline-offset: 4px; }

.crumbs { max-width: 1080px; margin: 16px auto 0; padding: 0 16px; font-size: 14px; color: var(--muted); }
.crumbs a { color: var(--muted); }
.crumbs .sep { margin: 0 6px; }

.hero { padding: 64px 0 48px; background: linear-gradient(180deg, var(--accent), var(--bg)); }
.hero h1 { font-size: clamp(30px, 5vw, 46px); line-height: 1.3; margin: 8px 0 16px; }
.eyebrow { color: var(--brand); font-weight: 700; margin: 0; font-size: 15px; }
.lead { font-size: 19px; color: var(--muted); max-width: 46em; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 24px; }
.btn { display: inline-block; background: var(--brand); color: var(--brand-ink); padding: 12px 20px; border-radius: 999px; text-decoration: none; font-weight: 700; }
.btn.ghost { background: transparent; color: var(--brand); border: 2px solid var(--brand); }

section { padding: 40px 0; }
section.band { background: var(--band); }
h2 { font-size: 26px; line-height: 1.4; margin: 0 0 20px; }
h3 { font-size: 19px; margin: 0 0 6px; }

.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 16px; }
.grid.three { grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); }
.card { display: block; border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; text-decoration: none; color: var(--ink); background: var(--bg); }
.card:hover { border-color: var(--brand); }
.card p, .pain p { margin: 0; color: var(--muted); font-size: 16px; }
.pain { border-left: 4px solid var(--brand); padding: 4px 0 4px 16px; }

.steps { list-style: none; padding: 0; margin: 0 0 16px; display: grid; grid-template-columns: repeat(auto-fill, minmax(180px, 1fr)); gap: 12px; counter-reset: s; }
.steps li { counter-increment: s; border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; background: var(--bg); }
.steps li::before { content: counter(s); display: inline-block; width: 28px; height: 28px; border-radius: 50%; background: var(--brand); color: var(--brand-ink); text-align: center; line-height: 28px; font-weight: 700; margin-bottom: 8px; }
.steps strong { display: block; }
.steps span { color: var(--muted); font-size: 15px; }
.checks { padding-left: 1.2em; }
.checks li { margin: 4px 0; }

.prose { padding-top: 24px; padding-bottom: 24px; max-width: 820px; }
.prose h1 { font-size: clamp(28px, 4vw, 38px); line-height: 1.35; margin: 8px 0 12px; }
.prose h2 { font-size: 23px; margin: 36px 0 12px; padding-top: 8px; border-top: 1px solid var(--line); }
.prose ul, .prose ol { padding-left: 1.3em; }
.prose li { margin: 4px 0; }
.prose table { width: 100%; border-collapse: collapse; margin: 12px 0; font-size: 15px; display: block; overflow-x: auto; }
.prose th, .prose td { border: 1px solid var(--line); padding: 8px 10px; text-align: left; vertical-align: top; min-width: 7em; }
.prose th { background: var(--band); }
.prose details { border: 1px solid var(--line); border-radius: var(--radius); padding: 12px 16px; margin: 10px 0; }
.prose summary { cursor: pointer; font-weight: 700; }
.related { padding-top: 0; }

.cta { background: var(--brand); color: var(--brand-ink); padding: 32px 0; }
.cta .wrap { display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between; gap: 12px; }
.cta p { margin: 0; font-size: 20px; font-weight: 700; }
.cta .btn { background: var(--brand-ink); color: var(--brand); }

.foot { border-top: 1px solid var(--line); padding: 32px 0 24px; font-size: 14px; color: var(--muted); }
.foot-in { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 16px 40px; }
.foot-brand { color: var(--ink); font-weight: 700; }
.foot-brand span { font-weight: 400; color: var(--muted); }
.foot-nav { display: grid; grid-template-columns: repeat(auto-fill, minmax(120px, 1fr)); gap: 4px 20px; flex: 1 1 100%; min-width: 0; max-width: 560px; }
@media (min-width: 720px) { .foot-nav { flex: 1 1 0; } }
.foot-nav a { color: var(--muted); text-decoration: none; }
.foot-nav a:hover { color: var(--brand); }
.foot-note { margin-top: 16px; font-size: 13px; }
.foot-note p { margin: 4px 0; }

/* 語言切換（2026-10-19 build_i18n.py附加） */
.langs { display: flex; gap: 10px; font-size: 14px; }
.langs a { text-decoration: none; color: var(--muted); }
.langs a[aria-current] { color: var(--ink); font-weight: 600; }
.badge { display: inline-block; vertical-align: middle; margin-left: 8px; font-size: 13px; font-weight: 600; line-height: 1; padding: 5px 9px; border-radius: 999px; background: var(--accent); color: var(--brand); white-space: nowrap; }
.contact-form { max-width: 640px; margin-top: 24px; }
.contact-form label { display: block; font-weight: 600; margin-bottom: 6px; }
.contact-form input, .contact-form select, .contact-form textarea { width: 100%; box-sizing: border-box; font: inherit; padding: 10px 12px; border: 1px solid var(--line, #c9d1d9); border-radius: 8px; background: var(--bg); color: var(--ink); }
.contact-form .form-note { font-size: 14px; color: var(--muted); }
.contact-form .hp { position: absolute; left: -10000px; width: 1px; height: 1px; overflow: hidden; }
:lang(ja) body, html:lang(ja) body { font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", "Yu Gothic", "Segoe UI", sans-serif; }