:root {
  --bg: #ffffff;
  --text: #1c2420;
  --muted: #5b6660;
  --line: #dde3df;
  --card: #f7f9f8;
  --accent: #196b24;
  --accent-soft: #e8f5ea;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121614;
    --text: #e6ebe8;
    --muted: #9aa5a0;
    --line: #2b332f;
    --card: #1a201d;
    --accent: #7fcf8c;
    --accent-soft: #1d3322;
  }
}

* { 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", sans-serif;
  line-height: 1.75;
}
header.site, main, footer.site { max-width: 960px; margin: 0 auto; padding: 0 16px; }

header.site { display: flex; align-items: baseline; gap: 14px; flex-wrap: wrap; padding-top: 24px; padding-bottom: 16px; border-bottom: 1px solid var(--line); }
.logo { font-weight: 700; font-size: 1.25rem; color: var(--text); text-decoration: none; letter-spacing: .02em; }
.tag { color: var(--muted); font-size: .9rem; }

.intro { padding: 48px 0 24px; }
.intro h1 { font-size: clamp(1.35rem, 3.2vw, 1.9rem); line-height: 1.5; margin: 0 0 16px; }
.intro p { color: var(--muted); max-width: 44em; margin: 0; }

section h2 { font-size: 1.05rem; margin: 32px 0 14px; letter-spacing: .04em; }
section h2 span { color: var(--muted); font-weight: 400; font-size: .85rem; margin-left: 10px; }

.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 14px; }
.card {
  display: flex; flex-direction: column;
  background: var(--card); border: 1px solid var(--line); border-radius: 10px;
  padding: 18px 18px 16px; color: var(--text); text-decoration: none;
  transition: border-color .15s, background .15s;
}
.card:hover, .card:focus-visible { border-color: var(--accent); background: var(--accent-soft); outline: none; }
.card h3 { margin: 0 0 6px; font-size: 1.05rem; }
.card p { margin: 0 0 12px; font-size: .92rem; color: var(--muted); flex: 1; }
.card .meta { font-size: .8rem; color: var(--accent); }

footer.site { margin-top: 56px; padding-top: 18px; padding-bottom: 40px; border-top: 1px solid var(--line); color: var(--muted); font-size: .8rem; }

@media (max-width: 600px) { br.wide { display: none; } .intro { padding-top: 32px; } }