/* Kanji Nova - sumi ink on washi, like the app. No web fonts: nothing is
   fetched from anyone else, so visiting the site tells no third party. */

:root {
  --paper: #fbf9f4;
  --surface: #ffffff;
  --ink: #1c1a17;
  --muted: #6b635b;
  --rule: #e4ddcf;
  --accent: #b02b26;
  --on-accent: #ffffff;
  --serif: 'Hiragino Mincho ProN', 'Yu Mincho', 'Noto Serif JP', 'Noto Serif CJK JP', Georgia, serif;
  --sans: system-ui, -apple-system, 'Segoe UI', Roboto, 'Hiragino Sans', 'Noto Sans JP', sans-serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --paper: #141311;
    --surface: #1d1b19;
    --ink: #f3efe8;
    --muted: #b8b0a6;
    --rule: #2c2926;
    --accent: #e5564e;
    --on-accent: #141311;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font: 17px/1.65 var(--sans);
}

a { color: var(--accent); text-underline-offset: 3px; }

.wrap { max-width: 760px; margin: 0 auto; padding: 0 20px; }

/* Header and footer */
.top { border-bottom: 1px solid var(--rule); }
.top .wrap { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding-block: 14px; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--ink); text-decoration: none; font-weight: 700; }
.seal {
  display: inline-grid; place-items: center;
  width: 32px; height: 32px; border-radius: 6px;
  background: var(--accent); color: var(--on-accent);
  font: 700 19px/1 var(--serif);
}
nav { display: flex; gap: 18px; flex-wrap: wrap; font-size: 15px; }
nav a { color: var(--muted); text-decoration: none; }
nav a:hover, nav a[aria-current='page'] { color: var(--ink); }

footer { border-top: 1px solid var(--rule); margin-top: 72px; color: var(--muted); font-size: 14px; }
footer .wrap { padding-block: 28px; display: grid; gap: 10px; }
footer nav a { color: var(--muted); }

/* Home */
.hero { text-align: center; padding: 72px 0 40px; }
.hero .mark { font: 400 84px/1.1 var(--serif); color: var(--accent); margin: 0; }
.hero h1 { font-size: clamp(32px, 7vw, 46px); line-height: 1.15; margin: 14px 0 8px; }
.hero .lede { color: var(--muted); font-size: 19px; margin: 0 auto; max-width: 34em; }
.badge {
  display: inline-block; margin-top: 26px; padding: 9px 16px;
  border: 1px solid var(--rule); border-radius: 999px;
  color: var(--muted); font-size: 15px; background: var(--surface);
}

.features { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 14px; margin: 24px 0; }
.feature {
  background: var(--surface); border: 1px solid var(--rule); border-radius: 14px;
  padding: 18px 18px 16px;
}
.feature .k { font: 400 30px/1 var(--serif); color: var(--accent); }
.feature h3 { margin: 12px 0 4px; font-size: 17px; }
.feature p { margin: 0; color: var(--muted); font-size: 15px; line-height: 1.55; }

.note { color: var(--muted); font-size: 14px; }

/* Text pages */
.page { padding-top: 40px; }
.page h1 { font-size: clamp(28px, 6vw, 38px); line-height: 1.2; margin: 0 0 6px; }
.page .meta { color: var(--muted); margin: 0 0 28px; font-size: 15px; }
.page h2 { font-size: 21px; margin: 36px 0 8px; }
.page h3 { font-size: 17px; margin: 22px 0 4px; }
.page p, .page li { overflow-wrap: anywhere; }
.page ul, .page ol { padding-left: 22px; }
.page li { margin: 4px 0; }

.card {
  background: var(--surface); border: 1px solid var(--rule); border-radius: 14px;
  padding: 18px 20px; margin: 18px 0;
}
.card > :first-child { margin-top: 0; }
.card > :last-child { margin-bottom: 0; }

.button {
  display: inline-block; padding: 12px 20px; border-radius: 10px;
  background: var(--accent); color: var(--on-accent); font-weight: 700; text-decoration: none;
}

table { border-collapse: collapse; width: 100%; font-size: 15px; }
th, td { text-align: left; vertical-align: top; padding: 10px 8px; border-bottom: 1px solid var(--rule); }
th { color: var(--muted); font-weight: 600; }
.table-scroll { overflow-x: auto; }

details { border-bottom: 1px solid var(--rule); padding: 12px 0; }
summary { cursor: pointer; font-weight: 600; }
details p { margin: 8px 0 0; color: var(--muted); }