:root {
  --bg: #f4f6f4;
  --panel: #ffffff;
  --text: #17201a;
  --muted: #4d5c52;
  --line: #d9e0da;
  --accent: #00913a;
  --accent-dark: #007730;
  --accent-soft: #e6f4ea;
  --shadow: 0 2px 10px rgba(0, 0, 0, .07);
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #101410;
    --panel: #1a211c;
    --text: #eef3ef;
    --muted: #a9b8ad;
    --line: #2d382f;
    --accent: #37c46a;
    --accent-dark: #2aa757;
    --accent-soft: #1d3326;
    --shadow: 0 2px 12px rgba(0, 0, 0, .5);
  }
}
:root[data-theme="dark"] {
  --bg: #101410;
  --panel: #1a211c;
  --text: #eef3ef;
  --muted: #a9b8ad;
  --line: #2d382f;
  --accent: #37c46a;
  --accent-dark: #2aa757;
  --accent-soft: #1d3326;
  --shadow: 0 2px 12px rgba(0, 0, 0, .5);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", "Yu Gothic", Meiryo, sans-serif;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.85;
  -webkit-text-size-adjust: 100%;
}

a { color: var(--accent-dark); }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) a { color: var(--accent); } }
:root[data-theme="dark"] a { color: var(--accent); }

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: var(--accent);
  padding: 12px 16px;
  box-shadow: var(--shadow);
}
.site-title {
  display: block;
  max-width: 760px;
  margin: 0 auto;
  color: #fff;
  text-decoration: none;
  font-size: 19px;
}
.site-title span {
  display: inline-block;
  margin-left: 8px;
  padding: 2px 10px;
  border-radius: 999px;
  background: rgba(255, 255, 255, .22);
  font-size: 15px;
  letter-spacing: .04em;
}

.wrap {
  max-width: 760px;
  margin: 0 auto;
  padding: 24px 16px 56px;
}

.lede {
  font-size: 30px;
  line-height: 1.45;
  margin: 8px 0 12px;
}
.lead-text {
  color: var(--muted);
  font-size: 16px;
  margin: 0 0 24px;
}

/* 紹介コードCTA */
.cta {
  background: var(--panel);
  border: 3px solid var(--accent);
  border-radius: 16px;
  padding: 20px 18px;
  margin: 28px 0;
  box-shadow: var(--shadow);
  text-align: center;
}
.cta-lead { margin: 0 0 14px; font-size: 18px; }
.code-row {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}
.code {
  background: var(--accent-soft);
  color: var(--text);
  border-radius: 10px;
  padding: 8px 16px;
  font-size: 26px;
  font-weight: 700;
  letter-spacing: .08em;
  font-family: "SF Mono", Consolas, monospace;
}
.copy-btn {
  border: 2px solid var(--accent);
  background: transparent;
  color: var(--accent-dark);
  border-radius: 10px;
  padding: 9px 16px;
  font-size: 16px;
  font-weight: 700;
  font-family: inherit;
  cursor: pointer;
}
.copy-btn.done { background: var(--accent); color: #fff; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .copy-btn { color: var(--accent); } }
:root[data-theme="dark"] .copy-btn { color: var(--accent); }

.cta-btn {
  display: block;
  background: var(--accent);
  color: #fff;
  text-decoration: none;
  border-radius: 12px;
  padding: 16px 18px;
  font-size: 18px;
  line-height: 1.4;
}
.cta-btn:active { background: var(--accent-dark); }

.section-title {
  font-size: 22px;
  margin: 36px 0 16px;
  padding-left: 12px;
  border-left: 6px solid var(--accent);
}

/* 記事カード */
.cards { display: grid; gap: 16px; }
.card {
  display: flex;
  gap: 14px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 14px;
  text-decoration: none;
  color: var(--text);
  box-shadow: var(--shadow);
}
.card-thumb {
  width: 108px;
  height: 108px;
  object-fit: cover;
  border-radius: 10px;
  flex: none;
  background: var(--accent-soft);
}
.card-text { min-width: 0; }
.card h2 { font-size: 18px; line-height: 1.5; margin: 0 0 6px; }
.card-date { margin: 0 0 6px; font-size: 14px; color: var(--muted); }
.card-excerpt { margin: 0; font-size: 15px; color: var(--muted); line-height: 1.7; }
@media (max-width: 480px) {
  .card { flex-direction: column; }
  .card-thumb { width: 100%; height: 160px; }
}

/* 記事本文 */
.post h1 { font-size: 27px; line-height: 1.5; margin: 8px 0 10px; }
.post-date { margin: 0 0 20px; color: var(--muted); font-size: 15px; }
.post-body { font-size: 17px; }
.post-body h2 {
  font-size: 23px;
  line-height: 1.5;
  margin: 40px 0 14px;
  padding-left: 12px;
  border-left: 6px solid var(--accent);
}
.post-body h3 { font-size: 20px; margin: 30px 0 10px; }
.post-body p { margin: 0 0 18px; }
.post-body ul, .post-body ol { padding-left: 1.4em; margin: 0 0 18px; }
.post-body li { margin-bottom: 6px; }
.post-body li p { margin: 0; }
.post-body figure { margin: 22px 0; }
.post-body img {
  display: block;
  max-width: 100%;
  height: auto;
  border-radius: 12px;
  border: 1px solid var(--line);
  margin: 0 auto;
}
.post-body figcaption {
  margin-top: 8px;
  text-align: center;
  font-size: 14px;
  color: var(--muted);
}
.post-body hr { border: 0; border-top: 2px dashed var(--line); margin: 32px 0; }
.post-body a { word-break: break-word; }

.post-nav { display: grid; gap: 12px; margin: 28px 0; }
.nav-card {
  display: block;
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 12px 14px;
  text-decoration: none;
  color: var(--text);
  font-size: 16px;
  line-height: 1.5;
}
.nav-card span {
  display: block;
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 4px;
}
.back { text-align: center; font-size: 16px; }

.site-footer {
  border-top: 1px solid var(--line);
  padding: 24px 16px 40px;
  text-align: center;
  color: var(--muted);
  font-size: 15px;
}
.site-footer p { margin: 0 0 8px; }
.site-footer .note { font-size: 14px; }