:root {
  --accent: #0a7d4f;
  --text: #222;
  --muted: #777;
  --bg: #fafaf8;
  --card: #ffffff;
  --border: #e5e5e0;
}

* { box-sizing: border-box; margin: 0; padding: 0; }

body {
  font-family: "Hiragino Kaku Gothic ProN", "Hiragino Sans", "Yu Gothic", Meiryo, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.9;
}

header {
  background: var(--accent);
  color: #fff;
  padding: 28px 16px;
  text-align: center;
}

header h1 { font-size: 26px; letter-spacing: 1px; }
header h1 a { color: #fff; text-decoration: none; }
header p { font-size: 13px; opacity: 0.9; margin-top: 6px; }

main {
  max-width: 720px;
  margin: 0 auto;
  padding: 32px 16px 64px;
}

.post-card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px 22px;
  margin-bottom: 18px;
}

.post-card a { color: var(--accent); text-decoration: none; font-weight: bold; font-size: 18px; }
.post-card a:hover { text-decoration: underline; }
.post-card .date { color: var(--muted); font-size: 13px; margin-bottom: 4px; }
.post-card .excerpt { font-size: 14px; color: #444; margin-top: 8px; }

article h1 { font-size: 24px; line-height: 1.5; margin-bottom: 8px; }
article .date { color: var(--muted); font-size: 13px; margin-bottom: 28px; }
article h2 {
  font-size: 20px;
  margin: 40px 0 16px;
  padding: 8px 12px;
  background: #eef5f1;
  border-left: 4px solid var(--accent);
  border-radius: 3px;
}
article h3 { font-size: 17px; margin: 28px 0 12px; color: var(--accent); }
article p { margin-bottom: 16px; }
article ul, article ol { margin: 0 0 16px 24px; }
article li { margin-bottom: 6px; }

table {
  width: 100%;
  border-collapse: collapse;
  margin: 16px 0 24px;
  font-size: 14px;
  background: var(--card);
}
th, td { border: 1px solid var(--border); padding: 10px 12px; text-align: left; }
th { background: #eef5f1; }

.note {
  background: #fff8e6;
  border: 1px solid #f0e0b0;
  border-radius: 8px;
  padding: 14px 16px;
  font-size: 13.5px;
  margin: 24px 0;
}

.back { display: inline-block; margin-top: 40px; color: var(--accent); text-decoration: none; }
.back:hover { text-decoration: underline; }

footer {
  text-align: center;
  color: var(--muted);
  font-size: 12px;
  padding: 24px 16px 40px;
}