:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #5c6370;
  --border: #e3e6ea;
  --accent: #1a56db;
  --code-bg: #f5f6f8;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg: #16181c;
    --fg: #e6e8ea;
    --muted: #9aa3af;
    --border: #2b2f36;
    --accent: #7aa7ff;
    --code-bg: #1f2228;
  }
}
:root[data-theme="dark"] {
  --bg: #16181c;
  --fg: #e6e8ea;
  --muted: #9aa3af;
  --border: #2b2f36;
  --accent: #7aa7ff;
  --code-bg: #1f2228;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Noto Sans JP", sans-serif;
  line-height: 1.75;
  font-size: 16px;
}
main { max-width: 720px; margin: 0 auto; padding: 4rem 16px 6rem; }
h1 { font-size: 1.9rem; line-height: 1.3; margin: 0 0 .25rem; letter-spacing: -.01em; }
.tagline { color: var(--muted); margin: 0 0 3rem; font-size: 1.05rem; }
h2 { font-size: 1.15rem; margin: 3rem 0 .75rem; letter-spacing: -.005em; }
p { margin: 0 0 1rem; }
ul { margin: 0 0 1rem; padding-left: 1.4rem; }
li { margin-bottom: .4rem; }
code {
  background: var(--code-bg);
  padding: .15em .4em;
  border-radius: 4px;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: .88em;
}
pre {
  background: var(--code-bg);
  padding: 1rem;
  border-radius: 8px;
  overflow-x: auto;
  border: 1px solid var(--border);
}
pre code { background: none; padding: 0; }
a { color: var(--accent); }
.notice {
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 0 8px 8px 0;
  padding: 1rem 1.25rem;
  margin: 2rem 0;
  background: var(--code-bg);
}
.notice p:last-child { margin-bottom: 0; }
footer {
  margin-top: 5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  color: var(--muted);
  font-size: .9rem;
}
footer a { font-weight: 500; }

.breadcrumb {
margin: 0 0 2rem;
font-size: .9rem;
}
.breadcrumb a {
text-decoration: none;
color: var(--muted);
}
.breadcrumb a:hover { color: var(--accent); }