:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --ink: #1b2330;
  --muted: #586174;
  --line: #d9dde4;
  --accent: #1d4ed8;
  --accent-ink: #ffffff;
  --soft: #e8eefc;
  --ok: #166534;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #12151a;
    --surface: #1b1f26;
    --ink: #e6e9ef;
    --muted: #9aa3b2;
    --line: #2f3541;
    --accent: #6b9bff;
    --accent-ink: #0b1220;
    --soft: #1c2740;
    --ok: #7ee2a0;
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Hiragino Sans", "Yu Gothic UI", "Noto Sans JP", "Meiryo", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.85;
}
a { color: var(--accent); text-underline-offset: 3px; }
a:focus-visible, .btn:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; }

.wrap { width: 100%; max-width: 980px; margin: 0 auto; padding: 0 20px; }

/* ---- header / footer ---- */
.site-header { border-bottom: 1px solid var(--line); background: var(--surface); }
.site-header .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; min-height: 60px; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-weight: 700; }
.brand img { width: 30px; height: 30px; border-radius: 7px; }
.site-nav { display: flex; gap: 18px; flex-wrap: wrap; font-size: 14px; }
.site-nav a { color: var(--muted); text-decoration: none; }
.site-nav a:hover { color: var(--accent); text-decoration: underline; }

.site-footer { margin-top: 72px; border-top: 1px solid var(--line); background: var(--surface); padding: 28px 0 40px; font-size: 14px; color: var(--muted); }
.site-footer .wrap { display: flex; flex-direction: column; gap: 10px; }
.site-footer nav { display: flex; gap: 18px; flex-wrap: wrap; }
.site-footer p { margin: 0; }

/* ---- buttons ---- */
.btn { display: inline-block; padding: 11px 20px; border-radius: 8px; border: 1px solid var(--accent); background: var(--accent); color: var(--accent-ink); font-weight: 700; text-decoration: none; }
.btn.ghost { background: transparent; color: var(--accent); }
.btn-row { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 24px; }

/* ---- top page ---- */
.hero { padding: 56px 0 24px; }
.hero .wrap { display: grid; gap: 40px; align-items: center; }
.hero h1 { margin: 0 0 16px; font-size: clamp(28px, 5vw, 42px); line-height: 1.35; letter-spacing: 0.01em; }
.hero p.lead { margin: 0; color: var(--muted); max-width: 30em; }
@media (min-width: 840px) { .hero .wrap { grid-template-columns: 1fr 1fr; } }

.demo { background: var(--surface); border: 1px solid var(--line); border-radius: 10px; overflow: hidden; font-size: 14px; line-height: 1.7; }
.demo-bar { display: flex; justify-content: space-between; padding: 8px 14px; background: var(--soft); border-bottom: 1px solid var(--line); font-weight: 700; font-size: 13px; }
.demo-bar span:last-child { color: var(--muted); font-weight: 400; }
.demo-body { padding: 12px 16px 14px; }
.demo-body h3 { margin: 12px 0 2px; font-size: 14px; padding-bottom: 2px; border-bottom: 1px solid var(--line); }
.demo-body h3:first-child { margin-top: 0; }
.demo-body p { margin: 4px 0; }
.demo-note { margin: 8px 0 0; font-size: 12px; color: var(--muted); }

section.block { padding: 48px 0 0; }
section.block h2 { margin: 0 0 16px; font-size: 24px; line-height: 1.4; }
.prose { max-width: 40rem; }
.prose p { margin: 0 0 1em; }

.steps { max-width: 40rem; margin: 0; padding-left: 1.4em; }
.steps li { margin-bottom: 8px; }

.plans { width: 100%; border-collapse: collapse; background: var(--surface); border: 1px solid var(--line); }
.plans th, .plans td { padding: 12px 14px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
.plans thead th { background: var(--soft); }
.plans tbody th { width: 28%; font-weight: 600; background: transparent; }
.plans tr:last-child th, .plans tr:last-child td { border-bottom: 0; }
.table-scroll { overflow-x: auto; }

.plain-list { margin: 0; padding-left: 1.3em; max-width: 40rem; }
.plain-list li { margin-bottom: 6px; }

.caution { max-width: 40rem; padding: 14px 18px; border-left: 4px solid var(--accent); background: var(--soft); border-radius: 0 8px 8px 0; }
.caution p { margin: 0 0 6px; }
.caution p:last-child { margin-bottom: 0; }

/* ---- legal pages ---- */
.doc { padding: 40px 0 0; }
.doc .wrap { max-width: 760px; }
.doc h1 { margin: 0 0 8px; font-size: 28px; line-height: 1.4; }
.doc .meta { margin: 0 0 32px; color: var(--muted); font-size: 14px; }
.doc h2 { margin: 36px 0 8px; font-size: 18px; line-height: 1.5; padding-bottom: 4px; border-bottom: 1px solid var(--line); }
.doc p, .doc li { margin: 0 0 0.8em; }
.doc ul, .doc ol { padding-left: 1.4em; margin: 0 0 1em; }

.spec { margin: 0; border: 1px solid var(--line); background: var(--surface); border-radius: 8px; }
.spec .row { display: grid; border-bottom: 1px solid var(--line); }
.spec .row:last-child { border-bottom: 0; }
.spec dt { padding: 12px 16px 0; font-weight: 700; }
.spec dd { margin: 0; padding: 0 16px 12px; }
@media (min-width: 680px) {
  .spec .row { grid-template-columns: 14em 1fr; }
  .spec dt, .spec dd { padding: 12px 16px; }
}