:root {
  --max: 1100px;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, "Noto Sans JP", sans-serif;
}

body {
  margin: 0;
  line-height: 1.75;
  color: #0f172a;
  background: #fff;
}

.site-header {
  background: #0f172a;
  color: #fff;
}

.wrap {
  max-width: var(--max);
  margin: auto;
  padding: 24px;
}

nav {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 16px;
}

nav a {
  color: #cbd5e1;
  text-decoration: none;
}

nav a:hover {
  color: #fff;
  text-decoration: underline;
}

h1 {
  margin: 0 0 8px;
  font-size: clamp(24px, 3vw, 36px);
}

.lead {
  margin: 0 0 20px;
  color: #cbd5e1;
}

.card {
  margin: 18px 0;
  padding: 18px;
  border: 1px solid #e5e7eb;
  border-radius: 8px;
  background: #fff;
}

.btn {
  display: inline-block;
  padding: 10px 14px;
  border: 1px solid #0ea5e9;
  border-radius: 8px;
  text-decoration: none;
}

.btn.primary {
  color: #fff;
  background: #0ea5e9;
}

.site-footer {
  margin-top: 40px;
  color: #64748b;
}

.site-footer a {
  color: #475569;
}

.back-to-top {
  position: fixed;
  right: max(16px, env(safe-area-inset-right));
  bottom: max(16px, env(safe-area-inset-bottom));
  z-index: 20;
  display: grid;
  width: 44px;
  height: 44px;
  padding: 0;
  place-items: center;
  border: 1px solid #0f172a;
  border-radius: 8px;
  color: #0f172a;
  background: #fff;
  box-shadow: 0 2px 8px rgb(15 23 42 / 18%);
  font: inherit;
  font-size: 22px;
  font-weight: 700;
  cursor: pointer;
}

.back-to-top:hover {
  color: #fff;
  background: #0f172a;
}

.back-to-top:focus-visible {
  outline: 3px solid #38bdf8;
  outline-offset: 2px;
}

.back-to-top[hidden] {
  display: none;
}
.column-list{border-top:1px solid #e5e7eb}.column-summary{padding:16px 0;border-bottom:1px solid #e5e7eb}.column-summary h3{margin:4px 0}.column-meta{margin:0 0 6px;color:#64748b;font-size:.9rem}.column-links{display:flex;flex-wrap:wrap;gap:8px 16px;margin:18px 0}