:root {
  color-scheme: light;
  --background: #f5f7f6;
  --surface: #ffffff;
  --text: #17201c;
  --muted: #5f6d66;
  --line: #dce4df;
  --accent: #176b45;
  --accent-soft: #e8f4ed;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", "Noto Sans JP", sans-serif;
  font-size: 16px;
  line-height: 1.75;
}

main {
  width: min(920px, calc(100% - 32px));
  margin: 40px auto;
  padding: clamp(24px, 5vw, 56px);
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: 0 12px 36px rgba(23, 32, 28, 0.06);
}

h1, h2, h3 { line-height: 1.35; }
h1 { margin: 0 0 12px; font-size: clamp(30px, 5vw, 44px); }
h2 { margin: 42px 0 12px; padding-top: 6px; font-size: 24px; }
h3 { margin: 24px 0 8px; font-size: 18px; }
p, ul, ol { margin: 10px 0; }
ul, ol { padding-left: 1.5rem; }
li + li { margin-top: 6px; }
a { color: var(--accent); text-underline-offset: 3px; }
strong { font-weight: 700; }

.meta {
  margin: 0 0 28px;
  color: var(--muted);
}

.notice {
  margin: 24px 0;
  padding: 16px 18px;
  background: var(--accent-soft);
  border-left: 4px solid var(--accent);
  border-radius: 8px;
}

.toc {
  margin: 28px 0 36px;
  padding: 20px 24px;
  background: #fafcfb;
  border: 1px solid var(--line);
  border-radius: 12px;
}

.toc h2 { margin: 0 0 8px; padding: 0; font-size: 18px; }

table {
  width: 100%;
  margin: 18px 0;
  border-collapse: collapse;
  font-size: 15px;
}

th, td {
  padding: 12px;
  border: 1px solid var(--line);
  text-align: left;
  vertical-align: top;
}

th { background: #f3f7f5; }

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

@media (max-width: 640px) {
  main { width: 100%; margin: 0; border: 0; border-radius: 0; }
  table { display: block; overflow-x: auto; }
}