:root {
  color-scheme: dark;
  --bg: #0b0b14;
  --bg-card: rgba(255, 255, 255, 0.04);
  --bg-card-strong: rgba(255, 255, 255, 0.07);
  --border: rgba(255, 255, 255, 0.08);
  --border-strong: rgba(255, 255, 255, 0.16);
  --fg: #f3f3f7;
  --muted: #a8a8c0;
  --pink: #ff8fc4;
  --aqua: #9ee7ff;
  --mint: #a6f7d3;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--fg);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP",
    "Yu Gothic UI", "Segoe UI", sans-serif;
  font-size: 16px;
  line-height: 1.85;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

.site-shell {
  max-width: 720px;
  margin: 0 auto;
  padding: 24px 20px 64px;
}

/* ---- header ---- */

.site-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 16px;
  margin-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.site-header .brand {
  font-size: 0.98rem;
  font-weight: 800;
  letter-spacing: 0.02em;
  background: linear-gradient(90deg, var(--pink) 0%, var(--aqua) 60%, var(--mint) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
  text-decoration: none;
}

.site-header nav a {
  font-size: 0.84rem;
  margin-left: 14px;
  color: var(--muted);
  text-decoration: none;
}

.site-header nav a:hover,
.site-header nav a:focus-visible {
  color: var(--fg);
}

/* ---- breadcrumb ---- */

.breadcrumb {
  font-size: 0.78rem;
  color: var(--muted);
  margin: 0 0 24px;
}

.breadcrumb a {
  color: var(--muted);
  text-decoration: none;
}

.breadcrumb a:hover { color: var(--aqua); }

.breadcrumb .sep { padding: 0 6px; opacity: 0.5; }

/* ---- article ---- */

article.lp {
  padding-bottom: 8px;
}

article.lp .eyebrow {
  display: inline-block;
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  color: var(--pink);
  margin: 0 0 8px;
  text-transform: uppercase;
}

article.lp h1 {
  font-size: 1.6rem;
  line-height: 1.35;
  margin: 0 0 12px;
  letter-spacing: 0.01em;
}

article.lp .lead {
  font-size: 1rem;
  color: var(--fg);
  margin: 0 0 28px;
}

article.lp h2 {
  font-size: 1.18rem;
  margin: 40px 0 8px;
  padding-left: 12px;
  border-left: 3px solid var(--pink);
  letter-spacing: 0.01em;
}

article.lp h3 {
  font-size: 1rem;
  margin: 24px 0 6px;
  color: var(--aqua);
}

article.lp p,
article.lp li {
  font-size: 0.95rem;
}

article.lp ul,
article.lp ol {
  padding-left: 1.2em;
  margin: 4px 0 14px;
}

article.lp ul li::marker { color: var(--mint); }
article.lp ol li::marker { color: var(--aqua); }

article.lp a { color: var(--aqua); }

/* ---- cards / callouts ---- */

.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 16px 18px;
  margin: 14px 0;
}

.card.tight { padding: 12px 14px; }

.card .card-title {
  font-size: 0.92rem;
  font-weight: 700;
  margin: 0 0 6px;
  color: var(--aqua);
}

.note {
  background: rgba(255, 143, 196, 0.07);
  border: 1px solid rgba(255, 143, 196, 0.25);
  border-radius: 12px;
  padding: 12px 14px;
  font-size: 0.9rem;
  margin: 14px 0;
}

.faq dt {
  font-weight: 700;
  color: var(--mint);
  margin-top: 16px;
}

.faq dd {
  margin: 4px 0 0;
  padding: 0;
  color: var(--fg);
}

/* ---- topic / category grid ---- */

.topic-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 10px;
  margin: 12px 0 6px;
}

.topic-grid li {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 10px 14px;
  font-size: 0.92rem;
  list-style: none;
}

.topic-grid li::marker { content: ""; }

@media (min-width: 540px) {
  .topic-grid { grid-template-columns: 1fr 1fr; }
}

/* ---- CTA ---- */

.cta {
  margin: 36px 0 16px;
  text-align: center;
}

.cta a {
  display: inline-block;
  padding: 14px 28px;
  border-radius: 999px;
  background: linear-gradient(95deg, var(--pink) 0%, var(--aqua) 100%);
  color: #0b0b14;
  font-weight: 800;
  font-size: 1rem;
  text-decoration: none;
  box-shadow: 0 16px 40px rgba(255, 143, 196, 0.18);
}

.cta a:hover,
.cta a:focus-visible {
  filter: brightness(1.05);
}

.cta-sub {
  display: block;
  font-size: 0.78rem;
  color: var(--muted);
  margin-top: 8px;
}

/* ---- related links ---- */

.related {
  margin-top: 48px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
}

.related h2 {
  font-size: 0.95rem;
  margin: 0 0 10px;
  color: var(--muted);
  border-left: none;
  padding-left: 0;
  letter-spacing: 0.02em;
}

.related ul {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
}

@media (min-width: 540px) {
  .related ul { grid-template-columns: 1fr 1fr; }
}

.related li a {
  display: block;
  padding: 12px 14px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  text-decoration: none;
  color: var(--fg);
  font-size: 0.92rem;
}

.related li a:hover,
.related li a:focus-visible {
  border-color: var(--border-strong);
  background: var(--bg-card-strong);
}

.related li a .label {
  display: block;
  color: var(--muted);
  font-size: 0.74rem;
  margin-bottom: 2px;
  letter-spacing: 0.02em;
}

/* ---- footer ---- */

.site-footer {
  margin-top: 40px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  font-size: 0.78rem;
  color: var(--muted);
  text-align: center;
}

.site-footer a {
  color: var(--muted);
  text-decoration: underline;
  text-underline-offset: 3px;
  margin: 0 6px;
}

.site-footer a:hover,
.site-footer a:focus-visible { color: var(--fg); }

/* ---- small utilities ---- */

.muted { color: var(--muted); }
.small { font-size: 0.82rem; }
.center { text-align: center; }
.pink { color: var(--pink); }
.aqua { color: var(--aqua); }
.mint { color: var(--mint); }