:root {
  --bg: #ffffff;
  --fg: #1a1a1a;
  --muted: #6b6b6b;
  --link: #0066cc;
  --border: #e5e5e5;
  --code-bg: #f5f5f7;
  --header-bg: #fafafa;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #1a1a1a;
    --fg: #f5f5f7;
    --muted: #a0a0a0;
    --link: #4da3ff;
    --border: #303030;
    --code-bg: #2a2a2a;
    --header-bg: #141414;
  }
}

* { box-sizing: border-box; }

html { font-size: 16px; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Hiragino Sans", "Yu Gothic", system-ui, sans-serif;
  line-height: 1.7;
  -webkit-text-size-adjust: 100%;
}

.site-header {
  background: var(--header-bg);
  border-bottom: 1px solid var(--border);
  padding: 1rem 1.5rem;
}

.brand {
  text-decoration: none;
  color: var(--fg);
  font-weight: 600;
  letter-spacing: 0.02em;
  font-size: 1.05rem;
}

.brand:hover { opacity: 0.7; }

.content {
  max-width: 720px;
  margin: 2.5rem auto;
  padding: 0 1.5rem;
}

h1, h2, h3, h4 { line-height: 1.3; }
h1 { font-size: 1.8rem; margin-top: 0; }
h2 {
  font-size: 1.35rem;
  margin-top: 2.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--border);
}
h3 { font-size: 1.1rem; margin-top: 1.75rem; }
h4 { font-size: 1rem; margin-top: 1.5rem; color: var(--muted); }

p { margin: 0.85em 0; }

a { color: var(--link); }
a:hover { text-decoration: underline; }

ul, ol { padding-left: 1.5em; }
li { margin: 0.25em 0; }

code {
  background: var(--code-bg);
  padding: 0.1em 0.4em;
  border-radius: 3px;
  font-size: 0.9em;
  font-family: "SF Mono", Menlo, Consolas, monospace;
}

pre {
  background: var(--code-bg);
  border-radius: 6px;
  padding: 1em;
  overflow-x: auto;
}

pre code { background: transparent; padding: 0; font-size: 0.85em; }

table {
  border-collapse: collapse;
  width: 100%;
  margin: 1rem 0;
  font-size: 0.95em;
}
th, td {
  border: 1px solid var(--border);
  padding: 0.5rem 0.75rem;
  text-align: left;
  vertical-align: top;
}
th { background: var(--code-bg); font-weight: 600; }

hr { border: none; border-top: 1px solid var(--border); margin: 2rem 0; }

blockquote {
  border-left: 3px solid var(--border);
  margin: 1em 0;
  padding: 0.25em 0 0.25em 1em;
  color: var(--muted);
}

.site-footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem;
  color: var(--muted);
  font-size: 0.85rem;
  text-align: center;
}

.inquiry-form-placeholder {
  border: 1px dashed var(--border);
  border-radius: 6px;
  padding: 1.5rem;
  text-align: center;
  margin: 1.5rem 0;
  background: var(--code-bg);
}

.inquiry-form-placeholder em {
  color: var(--muted);
  font-style: normal;
}