:root {
  color-scheme: light dark;
  --bg: #ffffff;
  --bg-soft: #f5f6f8;
  --card: #ffffff;
  --border: #e4e6eb;
  --text: #1c1e21;
  --text-soft: #5b6270;
  --accent: #d9577a;
  --accent-soft: #fdecf1;
  --radius: 14px;
  --maxw: 760px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #14161a;
    --bg-soft: #1b1e24;
    --card: #1b1e24;
    --border: #2b2f37;
    --text: #e8eaed;
    --text-soft: #a2a9b4;
    --accent: #f08aa6;
    --accent-soft: #3a1f28;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Hiragino Kaku Gothic ProN",
    "Noto Sans JP", "Yu Gothic", Meiryo, system-ui, sans-serif;
  line-height: 1.75;
  font-size: 16px;
  letter-spacing: 0.01em;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

/* header */
.site-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg);
  position: sticky;
  top: 0;
  z-index: 10;
}
.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 60px;
}
.brand { font-weight: 700; font-size: 1.15rem; color: var(--text); }
.brand:hover { text-decoration: none; }
.nav { display: flex; gap: 18px; flex-wrap: wrap; }
.nav a { color: var(--text-soft); font-size: 0.95rem; }
.nav a[aria-current="page"] { color: var(--text); font-weight: 600; }

/* main */
main { padding: 40px 0 8px; }
h1 { font-size: 1.7rem; line-height: 1.4; margin: 0 0 8px; }
h2 { font-size: 1.25rem; margin: 40px 0 12px; }
h3 { font-size: 1.02rem; margin: 26px 0 6px; }
p { margin: 12px 0; }
.lead { font-size: 1.05rem; color: var(--text-soft); margin-top: 0; }
.updated { color: var(--text-soft); font-size: 0.9rem; }

ul { padding-left: 1.25em; }
li { margin: 6px 0; }

.hero {
  padding: 16px 0 8px;
}
.hero h1 { font-size: 1.9rem; }

.cards { display: grid; gap: 14px; margin: 28px 0; }
@media (min-width: 620px) { .cards { grid-template-columns: 1fr 1fr; } }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px 18px 16px;
}
.card h3 { margin-top: 0; }
.card p { margin-bottom: 0; color: var(--text-soft); font-size: 0.95rem; }

.callout {
  background: var(--accent-soft);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  margin: 24px 0;
}
.callout p { margin: 6px 0; }
.callout strong { color: var(--text); }

.faq h3 { border-top: 1px solid var(--border); padding-top: 18px; }
.faq h3:first-of-type { border-top: 0; padding-top: 0; }
.faq p { color: var(--text); }

.btnrow { display: flex; gap: 12px; flex-wrap: wrap; margin: 22px 0; }
.btn {
  display: inline-block;
  padding: 10px 18px;
  border-radius: 10px;
  border: 1px solid var(--accent);
  color: var(--accent);
  font-weight: 600;
  font-size: 0.95rem;
}
.btn:hover { text-decoration: none; background: var(--accent-soft); }
.btn.primary { background: var(--accent); color: #fff; }
.btn.primary:hover { background: var(--accent); opacity: 0.92; }

/* footer */
.site-footer {
  border-top: 1px solid var(--border);
  margin-top: 48px;
  padding: 28px 0 40px;
  color: var(--text-soft);
  font-size: 0.9rem;
}
.site-footer .wrap { display: flex; flex-direction: column; gap: 6px; }
.site-footer .nav { gap: 14px; }

code { background: var(--bg-soft); padding: 1px 5px; border-radius: 5px; font-size: 0.9em; }
hr { border: 0; border-top: 1px solid var(--border); margin: 32px 0; }