:root {
  --bg: #fbfbfa;
  --surface: #ffffff;
  --ink: #16181d;
  --ink-2: #454b54;
  --ink-3: #767d87;
  --line: #e4e6e3;
  --accent: #167a45;
  --accent-soft: #eef5f0;
  --code-bg: #14171c;
  --maxw: 46rem;
}

* { box-sizing: border-box; }

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

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", "Segoe UI", sans-serif;
  font-size: 17px;
  line-height: 1.85;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); }

/* header */
.site-head {
  display: flex; align-items: center; justify-content: space-between;
  gap: 1rem; flex-wrap: wrap;
  max-width: var(--maxw); margin: 0 auto; padding: 1.4rem 1.25rem;
}
.brand { display: inline-flex; align-items: center; gap: .5rem; text-decoration: none; color: var(--ink); }
.brand-mark { font-size: 1.15rem; }
.brand-name { font-weight: 700; letter-spacing: .02em; }
.site-head nav { display: flex; gap: 1.1rem; font-size: .93rem; }
.site-head nav a { color: var(--ink-2); text-decoration: none; }
.site-head nav a:hover { color: var(--accent); }

main { max-width: var(--maxw); margin: 0 auto; padding: 0 1.25rem 4rem; }

/* hero */
.hero { padding: 2.2rem 0 2.6rem; border-bottom: 1px solid var(--line); }
.hero h1 { font-size: clamp(1.7rem, 5vw, 2.3rem); line-height: 1.4; margin: 0 0 1rem; letter-spacing: -.01em; }
.hero-lead { color: var(--ink-2); margin: 0; font-size: 1.02rem; }

/* listing */
.section-title { font-size: .82rem; letter-spacing: .16em; color: var(--ink-3); font-weight: 600; margin: 2.4rem 0 1rem; }
.cards { list-style: none; padding: 0; margin: 0; display: grid; gap: .9rem; }
.card a { display: block; text-decoration: none; color: inherit; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; padding: 1.25rem 1.35rem; transition: border-color .15s, transform .15s; }
.card a:hover { border-color: #c9cfc9; transform: translateY(-1px); }
.card h2 { font-size: 1.14rem; line-height: 1.55; margin: .35rem 0 .5rem; }
.card-date { font-size: .8rem; color: var(--ink-3); margin: 0; font-variant-numeric: tabular-nums; }
.card-desc { font-size: .95rem; color: var(--ink-2); margin: 0; }
.card.empty { color: var(--ink-3); padding: 1.25rem; }

/* post */
.post-head { padding: 2.2rem 0 1.6rem; border-bottom: 1px solid var(--line); margin-bottom: 2rem; }
.post-meta { font-size: .82rem; color: var(--ink-3); margin: 0 0 .7rem; font-variant-numeric: tabular-nums; }
.post-head h1 { font-size: clamp(1.55rem, 4.6vw, 2.1rem); line-height: 1.45; margin: 0 0 .9rem; letter-spacing: -.01em; }
.post-lead { color: var(--ink-2); margin: 0; }

.post-body h2 { font-size: 1.35rem; margin: 2.8rem 0 .9rem; padding-top: .3rem; line-height: 1.5; border-top: 2px solid var(--ink); display: inline-block; padding-right: .2rem; }
.post-body h3 { font-size: 1.1rem; margin: 2rem 0 .7rem; line-height: 1.55; }
.post-body p { margin: 0 0 1.25rem; }
.post-body ul, .post-body ol { padding-left: 1.35rem; margin: 0 0 1.35rem; }
.post-body li { margin-bottom: .5rem; }
.post-body strong { font-weight: 700; }
.post-body blockquote { margin: 1.5rem 0; padding: .9rem 1.1rem; background: var(--accent-soft); border-left: 3px solid var(--accent); border-radius: 0 8px 8px 0; color: var(--ink-2); }
.post-body blockquote p:last-child { margin-bottom: 0; }
.post-body hr { border: 0; border-top: 1px solid var(--line); margin: 2.5rem 0; }

.post-body code { background: #eef0ec; padding: .12em .38em; border-radius: 4px; font-size: .88em; font-family: ui-monospace, SFMono-Regular, Menlo, monospace; }
.post-body pre { background: var(--code-bg); color: #e6e9ee; padding: 1.1rem 1.2rem; border-radius: 10px; overflow-x: auto; margin: 0 0 1.5rem; font-size: .86rem; line-height: 1.7; }
.post-body pre code { background: none; padding: 0; color: inherit; font-size: inherit; }

.post-body table { width: 100%; border-collapse: collapse; margin: 0 0 1.6rem; font-size: .93rem; display: block; overflow-x: auto; }
.post-body th, .post-body td { border: 1px solid var(--line); padding: .6rem .75rem; text-align: left; vertical-align: top; }
.post-body th { background: #f3f5f2; font-weight: 600; white-space: nowrap; }

/* cta */
.cta { background: var(--surface); border: 1px solid var(--line); border-top: 3px solid var(--accent); border-radius: 12px; padding: 1.6rem 1.5rem; margin: 3rem 0 0; }
.cta-label { font-size: .74rem; letter-spacing: .14em; color: var(--accent); font-weight: 700; margin: 0 0 .6rem; }
.cta h3 { font-size: 1.12rem; line-height: 1.6; margin: 0 0 .8rem; }
.cta p { font-size: .95rem; color: var(--ink-2); margin: 0 0 .9rem; }
.cta-spec { font-size: .87rem !important; color: var(--ink-3) !important; }
.cta-btn { display: inline-block; background: var(--accent); color: #fff; text-decoration: none; font-weight: 600; padding: .8rem 1.4rem; border-radius: 8px; font-size: .96rem; }
.cta-btn:hover { background: #12653a; }
.cta-fine { font-size: .82rem !important; color: var(--ink-3) !important; margin: .85rem 0 0 !important; }

.back { margin: 2.5rem 0 0; font-size: .93rem; }
.back a { text-decoration: none; }

/* footer */
.site-foot { border-top: 1px solid var(--line); max-width: var(--maxw); margin: 0 auto; padding: 2rem 1.25rem 3rem; }
.foot-note { font-size: .9rem; color: var(--ink-2); margin: 0 0 .4rem; }
.foot-sub { font-size: .82rem; color: var(--ink-3); margin: 0; }

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101215; --surface: #171a1f; --ink: #e9ecef; --ink-2: #b3bac2; --ink-3: #848d97;
    --line: #262b32; --accent: #4ec98a; --accent-soft: #16241c; --code-bg: #0b0d10;
  }
  .post-body code { background: #21262d; }
  .post-body th { background: #1c2027; }
  .card a:hover { border-color: #3a424c; }
  .cta-btn { color: #08120c; }
  .cta-btn:hover { background: #6ad79e; }
}

/* 記事内の図版（スクリーンショット） */
.post-body img {
  display: block;
  max-width: 100%;
  height: auto;
  margin: 1.6rem auto;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: #fff;
}

/* 広告表記（景表法5条3号・内閣府告示19号）— 本文より前に、読者が最初に認識できる位置へ */
.aff-disclosure {
  display: block;
  margin: 1.4rem 0 1.8rem;
  padding: .85rem 1rem;
  border: 1px solid var(--line);
  border-left: 4px solid #b8860b;
  border-radius: 4px;
  background: color-mix(in srgb, #b8860b 6%, transparent);
  font-size: .875rem;
  line-height: 1.7;
}
.aff-disclosure strong { display: block; margin-bottom: .25rem; font-size: .9rem; }
.aff-disclosure span { display: block; opacity: .85; }

/* 記事中の広告リンク */
.aff-link {
  margin: 1.6rem 0;
  padding: .9rem 1rem;
  border: 1px solid var(--line);
  border-radius: 6px;
}
.aff-link a { font-weight: 600; }
.aff-link .aff-note { display: block; margin-top: .3rem; font-size: .85rem; opacity: .8; }